The evaluation of continuous fetal heart rate monitoring in high-risk pregnancy ALBERT
D.
HAVERKAMP.
HORACE
E.
THOMPSON,
JOHN
G.
O.Ol). This trend is unexplained. Forty-six of the auscultatetl patients had nonreassuring fetal heart rate patterns. Three of these patients (7 per cent) had either very low Apgar scores or prolonged neonatal problems. In reviewing these three cases,
it was felt
that
knowledge
of the
monitor
tracing
*For further reference, the internal electronically monitored patients will be called the monitored group and the auscultated patients, with the monitor not available. will be
at the time would not have changed the outcome of these infants. There are definite differences in the two groups in the frequency distribution of the methods of delivery due to the higher rate of cesarean sections in the monitored group (Table VI). Cesarean sections were significantly more prevalent (P < 0.01) in the moni-
called
tored
the auscultated
group.
group
(40
of the
242
patients
or
lfi.5
per
cent)
Continuous FHR monitoring in high-risk pregnancy
Volume Number
125 3
Table
IV. Race and marital
status Monitored
Ausculated
Marital RlXe White Spanish-American Black American Indian Oriental Total
Table
313
status
Marital
No.
S
M
D
W
46 105 34 6 - 0 191
15 32 19 1 0 8
28 63 14 5 - 0 110
3 9 1 0 22 13
0 1 0 0
No. 60 97 28 6
S
M
19 30 21 2
38 64 4 2 A 108
status D
W
3 3 3 2 0
0 0 3 0 !? 0
ii
V. Heart rate FHR pattern, early labor < 5 cm.
Normal Acceleration Early dec. VDa* VDb VDc LD VDa + ED VDb + ED VDc + ED VDa + L,D VDb + LD VDc + LD LD + ED None
*VDa
= mild
A
M
25 56 52 5 0 1 1 5 0 1 0 0
25 65 38 2 4 3 4 4 0 0 2
!i 93 P = 0.1634 variable;
VDb
: 4 88
= moderate
FHR pattern, late labor > 5 cm. Total 50 121 90 7 4 4 5 9 0 1 2 1 2 6 181
variable;
A
M
24
21 61 91 15 3 5 3 13 2 0 3 3 0 1 20
2 27 8 0 5 15 1 1 0 0 0 9 10 P = 0.0056 VDc
= severe
than in the auscultated group (16 of the 24 1 patients or 6.6 per cent) (Table VII). The cesarean section rate for fetal distress in the monitored group (18 of 242 patients or 7.4 per cent) was also significantly higher (P < 0.01) than that of the auscultated group (3 of 241 patients or 1.2 per cent) (Table VIII). Thus, diagnosis of fetal distress has a direct relationship to the number of cesarean sections performed. There was no difference between groups for frequency of cesarean sections when no fetal distress was detected. There was also a significant difference in type of anesthesia (P < 0.05) (Table IX). This appears to be attributable to the more frequent use of general anesthesia in the monitored group related to the increased need for cesarean sections. Regarding morbidity data related to monitoring, there were no uterine perforations or inductions of amniotic fluid into the mother’s circulatory system recognized in any of the 483 mothers in the study. The postpartum infection rate was significantly higher
variable;
FHR pattern, 2nd stage labor Total 45 123 170 42 11 5 8 28 3 1 3 3 0 10 30
LD
A
M
26 13 13 58 23 4 0 19 2 3 1 1 0 1 46 P = 0.2030
18 10 10 62 22 4 0 8 0 4 0 0 0 0 67
= late deceleration;
ED = early
Total 44 23 23 120 45 8 0 27 2 7 1 0 1 113
deceleration.
(P < 0.01) for the monitored group (31 of 234 patients or 13.2 per cent) than for the auscultated group (11 of 237 patients or 4.6 per cent).* This is partly due to the increased number of cesarean sections in the monitored patients (40) compared to the auscultated patients (16) and the higher rate of postpartum infection engendered by cesarean sections (9 of 38 patients or 23.7 per cent) for the monitored group and 3 of 15 patients or 20.0 per cent in the auscultated group.? However, even correcting for cesarean section the increased postpartum infection rate of the monitored group is still significant (P < 0.0 I). Since the data show the group comparable in all aspects such as hours of ruptured membranes, risk, age, parity, presence of meconium, etc., this difference is unexplained. *It should be noted that data for postpartum infection is missing for eight of the monitored patients and four of the auscultated. TPostpartum infection data are missing for two monitored cesarean section patients and one auscultated.
314
Haverkamp
Table
VI.
June 1. 1976 Am. J. Obstet. Gvnecol.
et al.
Delivery
(483 patients)
SSCVD ELF Mid forceps Cesarean section Cesarean section for fetal distress Breech
Table
A*
M
Totul
145 74
137 57
282
4 13 3
3
2
7
7
*A = Auscultated (241); M = monitored Table
VII.
Cesarean
0.0047
(242).
section .4*
M
16
Yes
N0
2::
225
P = 0.0011 *A = Auscultated; M = monitored. Table
VIII.
Cesarean
section-fetal
distress
‘4 * Yes No
M
3 23X P = 0.0018
IX.
Anesthesia A
Epidural Pudental General Other None A
Total
P due
69
.‘,1
120
85
83
168 43 89 62
12 40 34
31 49 28
P zIalur
7.2705 7.2684
0.006 0.006
0.811
35.9245 35.0443
0.737 0.803
0.420
M
PO, A M
15.9875 16.6625
0.602 0.757
0.4X5
31.9371 31.1586
1.456 1.588
0.7 18
7.3473 7.3455
0.004 0.005
0.780
30.6580 30.6026
0.444 0.46 1
0.93 1
25.5801 26.3922
0.573 0.588
0.323
56.9956 57.6164
1.224 1.330
0.732
39.7229 39.4359
0.274 0.268
0.454
A” M Pco, A
02
A M ver1ous: PH A M Pco, A M
PO, A M 02
(483 patients) M
S.E.
18 224
*A = Auscultated; M = monitored. Table
Mean Arterial: PH
35 21
?I
Cord samples
P 1mlur
131
22 IX
X.
= Auscultated (241); M = monitored
A M V base excess A M *A = Auscultated:
0.0183
(242).
The mean arterial and venous cord pH, Pco~, O2 saturation. buffer base. base excess. and standard bicarbonate revealed no differences in the two groups (Table X). Also, there are no differences in the distribution of low venous pH and low arterial cord pH’s (Table XI). The infant outcome shows the mean 1 minute Apgar score to be approximately the same for both groups. The number of Apgar scores at 1 minute that were 7 or below also show no difference. The mean 5 minute Apgar score was better in the auscultated group at a borderline significance of P = 0.085 (Table XII). The number of 5 minute Apgar scores 7 or below were increased in the monitored group (13 vs. 5) with a borderline statistical significance of P = < 0.09 (Table XIII). Infant morbidity is tabulated in ‘l-able XIV. There were no differences in any measured area of perinatal morbidity including the need for intensive-care nurs-
M = monitored
ery, intubation of the infant, seizures, lethargy, jaundice, jitteriness in the first 24 hours, and temperature abnormality. The difference between the number of infants requiring intermittent positive pressure ventilation ar 2 minutes (5 of 242 patients or 2.1 per cent for the monitored group, and 0 of 241 patients or 0 per cent for the auscultated group) was of borderline significance with a P value of 7.20 Total
23 138 161
Venous: ~7.25 >7.25 Total *A
Table XII. Apgar 1 1:
Apgar A M
5:
*A.=
180
9.17 9.02 Auscultated
0.8572
Apgar 5 minute: 57 >7
12 2% 234
(241):
(
Total
0.2516 *A
scores, 1 and 5 minute
7.88 7.74
Apgar 1 minute: 57 >7 Total
135
M = monitored.
Mean
SE.
(483 patients) 1
0.09 0.011
Table
= Auscultated;
XIV.
Infant
scores (483 patients) A*
M
P vale
62 179 241
70 -172 242
0.5236
5 22 241
13 229 242
0.085
M = monitored.
neonatal
indices (483 patients)
Pvalw
0.260
0.05 0.07 M = monitored
Apgar
P value
25
18 217 235
= Auscultated;
Apgar A* M
M
XIII.
0.0944 (242).
Intensive-care Temperate
ment of uterine contractions would be a superior method of intrapartum evaluation. The data are more readable, reproducible, and complete than periodic auscultation of the fetal heart tones. Numerous centers in recent years have cited improved perinatal outcome among patients monitored compared to auscultated patients or to the premonitoring era. However, in the present investigation comparing the monitored to the auscultated patient. the over-all perinatal outcome in high-risk pregnancies was not improved with the use of monitoring techniques. There are a number of potential difficulties in the methods and analysis of this study. In evaluating the efficacy of intrapartum electronic monitoring, various problems are inherent. First, there is a lack of uniformity in terminology and methods of interpretation. Second, interpretation of various heart ratt patterns changed as more information has appeared over a relatively short time span. Finally, there is frequently disagreement between investigators as to the significance of various fetal heart rate patterns and patient management. One might conclude that the interpretation of fetal heart rate patterns is not an exact science. It is difficult to select appropriate end points in evaluating perinatal outcome. The most clearly defined is perinatal death but, with present rates so low in this country, especially for term infants, very large numbers of patients are needed to demonstrate any real difference. Apgar scores were once thought to be a good indicator of fetal well-being, but longitudinal
nursery abnormalities
Jaundice Lethargy Seizures Jitteriness
Spontaneous respiration Need to intubate Intermittant *A
positive
= Auscultated
315
pressure (241);
at 2 minutes
M = monitored
A*
M
28
35
7; 21 2 9 4 4 0
7: 19 2 11 7” 5
(242).
studies have recently shown relatively poor correlation with neurologic testing at several years of age. Also, 5 minute Apgar scores have been dramatically improved with the present active resuscitation of the infant by trained physicians. Thus, the number of babies with low 5 minute scores is so low that very large numbers of patients are needed to show the effectiveness of a new method of care. Cord blood gases have also been used as end points in evaluating infant outcome. Their correlation with long-term infant outcome is not known. The pH determination has seemed the most useful but in this study low Apgar scores correlated with low pH values in only half of the cases in the preliminary evaluation. When utilizing the nursery course as an end point, it is obvious that postnatal events need not be related to intrapartum stress per se but these could result from other factors in the antepartum, intrapartum, and postnatal course. Finally, the infant’s longitudinal course over several years was not recorded in this investigation. When such a study is contemplated, it should include: socioeconomic, racial-genetic, anteparturn, intrapartum, postnatal, and other variables which make the final interpretation of this end point difficult and time consuming. There is an apparent trend in the present study for the monitored patients to develop more ominous patterns in the early first stage of labor. When the
316
Haverkamp et al
whole labor is evaluated, this trend is no longer apparent. Actual intrapartum jeopardy is difficult to document because of the problem in evaluating the results of many hours of tracings. The patterns may be nonreassuring for various periods of time and then become normal. There are subtle, less obvious factors involved in the actual care of laboring patients which could influence infant outcome. In this study, for example, the patients who were auscultated had individualized nursing care with one of the project nurses at the bedside almost continually. Very close physical contact with the patient was necessary for the nurse to auscultate fetal heart tones adequately. This was not true to the same degree with the monitored group. Nursing attention to the gravida with respect to maternal comfort. emotional and “laying on of’ hands” could have a support. significant impact on the fetus. ‘41~0, despite the facr that a monitor was attached to the patient, the machinerv was not at the bedside but in the hall. Patients who have a monitor ad.jacent to their bed are often bothered and stressed by flashing light, the sound produced with each fetal heart beat. and hearing or seeing decelerations even when they are benign. The authors have the impression that the reassuring psychological atmosphere created by personal nurse interaction and the absence of the recording machine in auscultated patients contributed to the excellent infant outcome in auscultated patients. One of the principal observations in this study was the striking increase in cesarean sections performed for fetal distress in the monitored group. This provides evidence that the electronic fetal monit,or is associated with an increased section rate and this without apparent Improvement in fetal outcome when compared with an auscultated group. On review at the conclusion of the study. the investigators felt that two of 18 of these would not have been done today with newer knowledge of fetal heart rate patterns. ‘Thus it would appear by the measured infant outcome that some of these cesarean sections arc unnecessary. There was excellent over-all correlation of interpretation of fetal heart rate tracings with the independent reviewers. There was. at times, disagreement with respect to use of the tracings as the sole criteria for performing cesarean sections for fetal distress. It is our conclusion that the total clinical picture of the high-risk gravida must be considered in proper management of these patients. There were cases in which multiple problems existed before and during labor that were accompanied by ominous tracings which led the investigators to decide in favor of cesarean sections. It is important to consider fetal monitoring as one of
June 1, 1976 Am. j. Obstet. Gynecol.
many clinical measures that can be used to help evaluate a given labor but good clinical judgment encompassing all factors must be used in arriving at the optimal mode of managing each individual patient. Within the study patients, the postpartum infection rate was significantly higher in the monitored group (13.2 per cent) in contrast to auscultated patients (3.4 per cent). Although much of this is believed due to the increased number of cesarean sections performed in the former. the incidence remains higher when abdominal deliveries are excluded. Such a difference in the prevalence of endometritis between the two groups delivered vaginally remains unexplained. The excellent. outcome of the study infants, regardless of rnonitored or auscultated, among a high-risk group of pregnancies and of low socioeconomic statuh, is rather striking. There were no intrapartum deaths and a perinatal mortality rate of 6.2 per 1000. ‘Thr study patients’ superior results are due possibly co cxcellencc of. detailed care, but this could also reHect the exclusion of intrapartum deaths that occurred before the patient’s arrival at the hospital and the deaths in very small premature infants weighing less than 1,500 grams, who were excluded frorn the study. The latter figures contribute heavily to over-all perinatal mortality rates. The excellent outcome in the auscultated infant does not mean that close attention need not be paid to the laboring patient. especially the high-risk individual. This study had a one-to-one nurse-patient ratio with rigidly timed auscultations by trained clinical nurses. Auscultation of fetal heart tones every 1 to 2 hours on ;i busy labor floor. as one not infrequeritlv sees, is inadequate observation of the laboring patient. Another important consideration germaine to this discussion is the time, knowledge, and expense necessary to keep the monitoring equipment functional. It has been our experience that it is necessary to have trained electronic personnel to make on the spot adjustments and repairs. Obstetric units without this capability ma\; experience mechanical problems that will interfere with their intrapartum surveillance b\ monitoring. The apparent lack of improvement in perinatal outcome in high-risk pregnancies by the use of the electronic fetal monitoring in this study in comparison to auscultation is unexpected, when considering the current opinion expressed in the world literature. Although monitoring is a helpful adjunct in observing a labor, other ways including auscultation may turn out to be adequate, especially in smaller hospitals where procurement and proper use of sophisticated monitoring equipment may not be feasible. Further. ueil-
Continuous FHR monitoring in high-risk pregnancy
Volume 125 Number3
conducted studies on the value of electronic monitoring need to be carried out before large amounts of money and time are spent, perhaps unnecessarily. The over-all findings of this study in both groups of patients plus the excellent perinatal outcomes in a group of high-risk pregnant patients make it appear that it may be the staff, both nursing and medical, ant1 the facilities that are important in achieving an optimal outcome rather than the use of electronic monitoring per se.
317
The authors wish to thank Drs. E. Stewart Taylor and Watson Bowes of the University of Colorado for their encouragement and support of this study. We wish to recognize the constructive criticism of this project by Drs. Roger Freeman and Robert Resnick. We are indebted to Mrs. Cherri Taylor and Mrs. Vera Drose for their skilled technical assistance.
REFERENCES 1. Anonymous: Is fetal monitoring worthwhile? Br. Med. J. 1: 515, 1971. C. A., and Roberts, 2. Beard, R. W., Filshie, G. M., Knight, G. M.: Intensive care of high risk fetus in labour, J. Obstet. Gynaecol. Br. Commonw. 78: 865, 1971. 3. Gabert, H. A., and Stenchever, M. A.: Continuous electronic monitoring of fetal heart rate during labor, AM. J. OBSTET. GYNECOL. 115: 919, 1973. 4. Kelly, V. C., and Kulkarni, D.: Experiences with fetal monitoring in a community hospital, Obstet. Gynecol. 4: 818, 1973. fetal monitoring, 5. Paul, R. H., and Hon, E. H.: Clinical AM.J.OBSTET.GYNECOL. 118:529, 1974. 6. Paul, R. H.: Clinical fetal monitoring. Experience on a large clinical fetal monitoring, AM. J. OBSTET. GYNLCOL.. 113: 573, 1972. 7. Beard, R. W., Brudenell, F. M., Feroze, R. M., and Clayton, S. G.: The significance of the changes in the continuous fetal heart rate in the first stage of labour, J. Obstet. Gynaecol. Br. Commonw. 78: 882, 1971. 8. Saling, E. Z., and Dudenhausen, J. W.: The present situation of clinical monitoring of the fetus during labor, J. Perinatal Med. 73: 144, 1973.
Discussion DR. JOHN
S. GILLAM,
Des
Moines,
Iowa.
Dr.
Haver-
kamp and his associates, at the risk of critical analysis from both the relatively uninformed, such as myself and the highly informed in maternal and neonatal physiology, have not supplied the answer to the critical question raised by many for years. We needed to know the results of a well-conceived blind study demonstrating the efficacy of continuous electronic fetal monitoring in reducing the perinatal mortality. In the conception of such a study, the fetus needed to be protected. I feel that in this study, even though blind, the fetus had certain advantages over most of being protected by the continuous and close surveillance of a competent nurse. There is not one of us who does not appreciate the value of competent people. I can find no fault with the protocol of this study. The results imply that even in this high-caliber tertiary-care center, too many cesarean sections were done in the interest of the fetus and I agree. The text leaves
one
with
“high-risk” group, fetus is considered
a comfortable
feeling
that
in
this
the survival and adequacy of the the primary responsibility. At least
9. Shenker, L.: Clinical experience with fetal heart rate monitoring on one thousand patients in labor, AM. J. OBSTET.GYNECOL. 115: 1111. 1973. 10. Shenker, L., Post, R. C., and Seiler, J. S.: Routine electronic monitoring of fetal heart rate and uterine activity during labor, Obstet. Gynecol. 46: 185, 1975. 11. Wood, C.: Difficulties in fetal heart rate monitoring, Int. J. Obstet. Gynecol. 10: 176, 1972. 12. Hon, E.: The present status of electronic monitoring of the human fetal heart, Int. J. Obstet. Gynecol. 10: 191, 1972. 13. Hon, E., Zanni, D., and Quilligan, E. J.: The neonatal value of fetal monitoring, AM. J. OBSTET. GYNECOL. 122: 508, 1975. 14. Beard, R. W.: The effect of fetal blood sampling on cesarean section for fetal distress, J. Obstet. Gynaecol. Br. Commonw. 75: 1291, 1968. 15. Goodwin, J. W., Dunne, J. T., and Thomas, R. W.: Antenartum identification of the fetus at risk, Can. Med. As&. J. 101: 458, 1969. 16. Benson, R. c., Shubeck, F., Deutschberger, J., Weiss, W., and Berendes, H.: Fetal Heart rate as a predictor of fetal distress, Obstet. Gynecol. 32: 259, 1968.
the high section rate did not alter this, and the obligation of a “good start” has been fulfilled. With this accolade for an outstanding effort, let us now discuss mostly unanswered issues raised. The difference in numbers of abnormal patterns in early labor
between
the
two
groups,
if
unchanged
by
positional changes, remains unexplained. Some’ suggest fetal scalp blood-PH (FSB-PH) be done at the time of insertion of fetal scalp electrode. This would seem especially appropriate for prematures, or intrauterine growth-retarded fetuses. This FSB-PH, or other methods referred to later, utilized early in labor might shed light on these differences. The differences in morbidity between the purely monitored and the nurse-monitored patients is interesting. Others have noted it between monitored and unmonitored explanation. This study has shown another
without positive-
but unexplained-difference that can no longer be attributed to EFM techniques, since both groups had this. Perhaps Dr. Haverkamp’s suggestion regarding a pleasant nurse at the bedside, in the absence of a beeping monitor, merits consideration. It would seem that the cord blood studies would be
318
Haverkamp
June
et al.
enlightening, but the normals in both groups overshadow relevant results, it appears. Have the two groups of cesarean sections alone been compared? Perhaps even more significant would be the studies of the 18 monitored and three unmonitored where the sections were done for fetal distress, but, 1 presume, the numbers are too small to compare. The authors have repeatedly said that perhaps EFM should not be used as the basis for interference in the course of labor in high-risk patients, since the outcome was the same with EFM and competent nurse monitoring. But either of these relatively expensive methods, especially EFM, can be used as an alerting factor for considering the use of FSB-PH. At Broadlawns Polk County Hospital, other than for socioeconomic reasons, one third of our patients are in the “high-risk” clinic. Thirty per cent of all patients are monitored, but insufficient equipment deters us from monitoring the 50 per cent who should be. For the two years we have had EFM, our primary cesarean section rate has risen from 4.3 to 6.4 per cent, but in this same time. our attitudes toward breech presentations, prolonged labor, or membrane rupture, and cephalopelvic disproportion have become more conservative, resulting in an increase in the cesarean section rate for these problems. The monitored FHR abnormalities required support of FBS-PH determinations to justify interference. Our perinatal mortality rate has dropped from 21.2 to 12.4 per 1,000 live births in this same 2 yeal period. updating the work of many befort Recent reports,‘-” them, have recently shown that, by judging EFM tracings by currently acceptable criteria. only approximately one third of infants showing late deceleration with or without variable decelerations will show FSB-PH samples which would suggest the need of interference. Each in his own way has shown that TSA (the total area under the FHR baseline) whether measured by computer’ or the corometric “corallar\ overlay”’ can perhaps give a much higher correlation between significant FHR depression and the still ultimate FSB-PH. More work needs to be done on beat-to-beat variability. Thus. il is apparent thar Dr. Haverkamp and associates have settled some questions and raised others: (1) identifying high-risk patients and providing them with a perinatal environment for total care are obligatory; (2) the use of EFM is one of the valuable adjuncts, perhaps not yet fully developed, but without FSB-PH and newly emerging tools, it alone does not .justify interference in the normal course of labor; and (3) the questions of early labor FHR abnormalities and puerperal morbidity differences need, if possible, to be answered. In view of their well-demonstrated capabilities to conduct careful studies, we should all encourage them to conrinue their efforts, incorporating new modalities. It seems likely that their cesarean section rate-and possibly their perinatal mortality rare will be reduced.
I. 1976
Am. J. Ohstet. Gynecol.
REFERENCES
1. Tejani, N., Mann, L. I., Bhakthavathsalan, A., and Weiss, R. R.: Correlation of fetal heart rate-uterine contraction patterns and fetal scalp blood pH. In press. 2. Lowelsolm. R. I., Yeh, S. Y., Forsythe, A., and Hon, E. H.: Computer assessed fetal heart rate patterns and fetal scalp pH, Obstet. Gynecol. 46: 190, 1975. 3. Hon, E. H.. Zannini, D., and Quilligan, E. J.: ‘l’he neonatal value of fetal monitoring, AM. J. OBSTET. GYNECOL. 122: 508, 1975. DR. MORTOK A. STENCHEVER, Salt Lake City, Utah. This paper brings up a number of considerations with respect to electronic fetal monitoring. The first significant point to be made should involve the consideration of whether indeed the monitored and unmonitored groups were similar. Although the authors have pointed out that they were similar in a number ot parameters, it is difficult to lump all high-risk pregnancy patients into one group. For instance, high-risk scores are ,given to patients for a variety of reasons. Patients with similar scores may have entirely different diseases with entirely different prognoses with respecl to fetal outcome. The fact that the groups may IIOL be cotnparable is brought out by the findings that there were indeed more patients with significant late deceleration and serious prolonged variable deceleration patterns in the monitored group than there were in the unmonitored group. In addition, the monitored group had a greater postpartum infection rate than did the unmonitored group. Since both groups were exposed to the scalp electrode and the intrauterine catheter, the mechanics c)f monitoring cannot be implicated, and one ~.ouid have to suspect that there was a real tlif-ferencc between the two groups of patients. 111 addition, there was a somewhat larger number of premature infants; that is, infants delivered at 33 weeks’ gestation or earlier in the monitored group (seven) than in the unmonitored group (two) and of post-date patients in the monitored group (23) a\ opposed to the unmonitored group (20). While none oI’ these differences lend themselves to anv statistical significance, cumulatively they may explain some of the variances norctl. The next m+r point to consider is why the cesareart section rate \vas so much higher in the monitored group than iu the unmonitored group. M’as it real11 due to the information derived bv fetal monitoring or was it rather due to the fact that the groups tcere indeed different? I suspect that to a large extent it was due to the differences. Had the tracings of the unmonitored group been followed and decisions as to the performance of cesarean sections made because of‘ these, it would seem from the tracing patterns rhat cesarean section rate would have indeed been lower ill this group. Again, it would seem that the two groups were not comparable with respect to abnormal trarings, although again the numbers are small enough that the differences may not lend themselves to statistical significance. ‘Fhe increased number of late
Volume Number
125 3
deceleration patterns seen in the monitored group could possibly account for the increased number of low Apgar scores at 5 minutes in this group. We have found, as have others, that about 10 per cent of babies monitored have late deceleration patterns, and these are frequently related to low 5 minute Apgar scores, being patterns signifying placental insufficiency. Pla.. cental insufficiency is a problem which may be present long before labor, therefore leading to chronically depresssed babies. At the University of Utah College of Medicine we have monitored all pregnancies that could be monitored for the past 4 years. We have followed the nomenclature of Hon and have used fairly standard procedures for treating fetal distress when it occurs and for instituting delivery when the abnormal pat-, terns are not correctable. Although the first year of our study (1971) was primarily an observation year, the aggressive management of labor has been part of our program for the last 3 years. When comparing these 3 years with our first year, we find a decrease in low Apgar scores (6 or under) at 1 minute by approximately 50 per cent and a modest decrease in the number of low Apgar scores at 5 minutes. We have had no intrapartum fetal deaths during the past 3 years with the exception of those babies who were either grossly immature or suffering from congenital malformations. During this time our primary cesarean section rate because of fetal distress has been approximately 3 per cent. Our primary cesarean section rate has risen during the past 4 years, but this has been secondary to a complete change in attitude toward the care of patients in labor and an increase in the number of high-risk pregnancies we are seeing at our institution. During our 4 years of experience we have noted that approximately one third of our patients show variable deceleration patterns and 10 per cent show late deceleration patterns. These patterns have correlated very well to the findings at the time of delivery, in that the vast majority of variable deceleration patterns have been associated with some type of cord compromise. and three fourths of the late deceleration patterns have been related to placental insufficiency of one sort or another. We have found the monitoring patterns of great assistance in following these babies in labor and have noted the greatest reduction in the number of low Apgar scores in those babies with variable deceleration (cord complication) patterns. We have made some inroads in reducing the number of low Apgar scores in our late deceleration (placental insufficiency) group, but nothing as significant as with the variable group, again pointing to the fact that these problems are more chronic in nature. I would agree with the author that careful monitoring of the fetus by any means will improve the outcome. It should significantly decrease or eliminate the number of intrapartum deaths which occur on a service and should pick up fetal distress problems at an earlier period in time. Electronic fetal monitoring has
Continuous
FHR
monitoring
in high-risk
pregnancy
319
made it possible to follow a number of patients in labor more closely and to indeed act as an early warning mechanism for the distressed baby. If a hospital has the personnel to place a nurse or technician constantly at the mother’s bedside, then this might indeed replace fetal monitoring to some extent. There is no doubt that the presence of a monitor on a service improves the care of the patient in labor in most institutions’ experiences. I would like to take exception to the statements of the authors that many patients are upset by the presence of a monitor at the bedside. We have found in our experience that patients are indeed reassured by the flashing lights and the dials, probably because they realize that the staff is carefully watching the baby’s progress because of the apparatus. It would thus seem that by any mechanism, careful observation is the key to better outcome on an obstetric service, but electronic monitoring is an inexpensive, efficient, and accurate means of accomplishing this. DR. BILL QUILLAN, Fort Belvoir, Virginia. Would the author comment on the positioning of the patient who was monitored and the position changes required? Also, were there differences between those persons monitored and the unmonitored population in the amount of anesthesia used or the frequency of use of anesthesia? Could differences in use or amount contribute to the cesarean section rate due to druginduced changes in fetal heart rate or hypotensive induced changes in the fetal status? DR. JACQUES F. Roux, Montreal. Canada. When I was in Cleveland, we did a similar study and five years ago we’ discussed data which supported the thesis of Dr. Haverkamp. The main reason for which there is some discussion today is the fact that we all have difficulty in interpreting reliably the changes in fetal heart rate. This is well demonstrated in Dr. Cibil? paper. He showed how difficult it is to evaluate clinically changes in fetal heart rate in small-for-dates infants and during postmaturity. I believe that the increase in manpower alone with monitoring will decrease perinatal deaths because the supervision of labor is more thoughtful. I would ask Dr. Haverkamp if he thinks that his study could ever be improved and redesigned, using the fetal scalp pH in suspicious cases. That might improve his data. REFERENCES 1. ROUX, J. F., Wilson, R., Yeni-Komshian, H., Jassani, M., and Jordan, J.: Labor monitoring: a practical experience, Obstet. Gynecol. 36: 875, 1970. 2. Cibils, L. A.: Clinical significance of fetal heart rate patterns during labor. II Late decelerations, AM. J. OBSTET. GYNECOL. 123: 473, 1975.
DR. HAVERKAMP (Closing). Dr. Stenchever questioned the comparability of the two patient study groups. We randomly selected these patients and did everything possible to insure randomization. Statistical
320
Haverkamp
et al
comparisons between the two groups showed no difference in areas of race, age, parity, tnarital status, risk scores. reasons for inclusion in the study, etc. Over all we noted that there wet-e ominous FHK patterns in 30 of the auscultated and 39 of the electronicallv monitored patients. Again, this is not ;I statistically significant difference. However, there is an unexplained difference in ominous patterns in the early first stage of labor at less than 5 cm. difference. We do not know \vh\: there uas a difference in the infection rate among vaginal deliveries-higher in the tnonitored group. Perhaps the monitor made the examiner do tnore vaginal examinations. We just are unable to explain this trend. Dr. Stenchever alludes to a possible improvement in perinatal mortality rates and IOU i\pgar scores in his institution by recognizing fetal distress with monitors. We and many other institutions have noted improved perinatal mortality rates over the last several years but whether this is due to monitoring or multifactoral (antenatal testing, therapeutic abortion, increased
June 1. 1976 Am. J. Obstet. Cynecol.
obstetrical surveillance, improved neonatal nurser\ survival) is unknown. I think there are too many othelfactors that can change outcomes in comparing several year periods unless you have matched study groups. The position of the laboring patients tended to be OII the left side, especially if there were FHR abnormalities or any special concerns on the part of the physician in charge of labor. The type of anesthesia showed a significant dit’ferencc due to the increase in USCof general anesthesia in the electrically monitored group. ‘This USC of general anesthesia was due to the increase in cesarean sections in this group. 1 very much appreciate Dr. John Gilliam’s comments and we will be incorporating use of scalp pH sampling in a future study. In this future study, we will be following high-risk patients in labor by three methods in intrapartuni evaluation: (1) auscultations of fetal heart tones, (2) electronic FHR monitoring, and (3) electronic FHR monitoring with appropriate fetal scalp sampling and comparing the outcotnes.
D.
HAVERKAMP.
HORACE
E.
THOMPSON,
JOHN
G.
O.Ol). This trend is unexplained. Forty-six of the auscultatetl patients had nonreassuring fetal heart rate patterns. Three of these patients (7 per cent) had either very low Apgar scores or prolonged neonatal problems. In reviewing these three cases,
it was felt
that
knowledge
of the
monitor
tracing
*For further reference, the internal electronically monitored patients will be called the monitored group and the auscultated patients, with the monitor not available. will be
at the time would not have changed the outcome of these infants. There are definite differences in the two groups in the frequency distribution of the methods of delivery due to the higher rate of cesarean sections in the monitored group (Table VI). Cesarean sections were significantly more prevalent (P < 0.01) in the moni-
called
tored
the auscultated
group.
group
(40
of the
242
patients
or
lfi.5
per
cent)
Continuous FHR monitoring in high-risk pregnancy
Volume Number
125 3
Table
IV. Race and marital
status Monitored
Ausculated
Marital RlXe White Spanish-American Black American Indian Oriental Total
Table
313
status
Marital
No.
S
M
D
W
46 105 34 6 - 0 191
15 32 19 1 0 8
28 63 14 5 - 0 110
3 9 1 0 22 13
0 1 0 0
No. 60 97 28 6
S
M
19 30 21 2
38 64 4 2 A 108
status D
W
3 3 3 2 0
0 0 3 0 !? 0
ii
V. Heart rate FHR pattern, early labor < 5 cm.
Normal Acceleration Early dec. VDa* VDb VDc LD VDa + ED VDb + ED VDc + ED VDa + L,D VDb + LD VDc + LD LD + ED None
*VDa
= mild
A
M
25 56 52 5 0 1 1 5 0 1 0 0
25 65 38 2 4 3 4 4 0 0 2
!i 93 P = 0.1634 variable;
VDb
: 4 88
= moderate
FHR pattern, late labor > 5 cm. Total 50 121 90 7 4 4 5 9 0 1 2 1 2 6 181
variable;
A
M
24
21 61 91 15 3 5 3 13 2 0 3 3 0 1 20
2 27 8 0 5 15 1 1 0 0 0 9 10 P = 0.0056 VDc
= severe
than in the auscultated group (16 of the 24 1 patients or 6.6 per cent) (Table VII). The cesarean section rate for fetal distress in the monitored group (18 of 242 patients or 7.4 per cent) was also significantly higher (P < 0.01) than that of the auscultated group (3 of 241 patients or 1.2 per cent) (Table VIII). Thus, diagnosis of fetal distress has a direct relationship to the number of cesarean sections performed. There was no difference between groups for frequency of cesarean sections when no fetal distress was detected. There was also a significant difference in type of anesthesia (P < 0.05) (Table IX). This appears to be attributable to the more frequent use of general anesthesia in the monitored group related to the increased need for cesarean sections. Regarding morbidity data related to monitoring, there were no uterine perforations or inductions of amniotic fluid into the mother’s circulatory system recognized in any of the 483 mothers in the study. The postpartum infection rate was significantly higher
variable;
FHR pattern, 2nd stage labor Total 45 123 170 42 11 5 8 28 3 1 3 3 0 10 30
LD
A
M
26 13 13 58 23 4 0 19 2 3 1 1 0 1 46 P = 0.2030
18 10 10 62 22 4 0 8 0 4 0 0 0 0 67
= late deceleration;
ED = early
Total 44 23 23 120 45 8 0 27 2 7 1 0 1 113
deceleration.
(P < 0.01) for the monitored group (31 of 234 patients or 13.2 per cent) than for the auscultated group (11 of 237 patients or 4.6 per cent).* This is partly due to the increased number of cesarean sections in the monitored patients (40) compared to the auscultated patients (16) and the higher rate of postpartum infection engendered by cesarean sections (9 of 38 patients or 23.7 per cent) for the monitored group and 3 of 15 patients or 20.0 per cent in the auscultated group.? However, even correcting for cesarean section the increased postpartum infection rate of the monitored group is still significant (P < 0.0 I). Since the data show the group comparable in all aspects such as hours of ruptured membranes, risk, age, parity, presence of meconium, etc., this difference is unexplained. *It should be noted that data for postpartum infection is missing for eight of the monitored patients and four of the auscultated. TPostpartum infection data are missing for two monitored cesarean section patients and one auscultated.
314
Haverkamp
Table
VI.
June 1. 1976 Am. J. Obstet. Gvnecol.
et al.
Delivery
(483 patients)
SSCVD ELF Mid forceps Cesarean section Cesarean section for fetal distress Breech
Table
A*
M
Totul
145 74
137 57
282
4 13 3
3
2
7
7
*A = Auscultated (241); M = monitored Table
VII.
Cesarean
0.0047
(242).
section .4*
M
16
Yes
N0
2::
225
P = 0.0011 *A = Auscultated; M = monitored. Table
VIII.
Cesarean
section-fetal
distress
‘4 * Yes No
M
3 23X P = 0.0018
IX.
Anesthesia A
Epidural Pudental General Other None A
Total
P due
69
.‘,1
120
85
83
168 43 89 62
12 40 34
31 49 28
P zIalur
7.2705 7.2684
0.006 0.006
0.811
35.9245 35.0443
0.737 0.803
0.420
M
PO, A M
15.9875 16.6625
0.602 0.757
0.4X5
31.9371 31.1586
1.456 1.588
0.7 18
7.3473 7.3455
0.004 0.005
0.780
30.6580 30.6026
0.444 0.46 1
0.93 1
25.5801 26.3922
0.573 0.588
0.323
56.9956 57.6164
1.224 1.330
0.732
39.7229 39.4359
0.274 0.268
0.454
A” M Pco, A
02
A M ver1ous: PH A M Pco, A M
PO, A M 02
(483 patients) M
S.E.
18 224
*A = Auscultated; M = monitored. Table
Mean Arterial: PH
35 21
?I
Cord samples
P 1mlur
131
22 IX
X.
= Auscultated (241); M = monitored
A M V base excess A M *A = Auscultated:
0.0183
(242).
The mean arterial and venous cord pH, Pco~, O2 saturation. buffer base. base excess. and standard bicarbonate revealed no differences in the two groups (Table X). Also, there are no differences in the distribution of low venous pH and low arterial cord pH’s (Table XI). The infant outcome shows the mean 1 minute Apgar score to be approximately the same for both groups. The number of Apgar scores at 1 minute that were 7 or below also show no difference. The mean 5 minute Apgar score was better in the auscultated group at a borderline significance of P = 0.085 (Table XII). The number of 5 minute Apgar scores 7 or below were increased in the monitored group (13 vs. 5) with a borderline statistical significance of P = < 0.09 (Table XIII). Infant morbidity is tabulated in ‘l-able XIV. There were no differences in any measured area of perinatal morbidity including the need for intensive-care nurs-
M = monitored
ery, intubation of the infant, seizures, lethargy, jaundice, jitteriness in the first 24 hours, and temperature abnormality. The difference between the number of infants requiring intermittent positive pressure ventilation ar 2 minutes (5 of 242 patients or 2.1 per cent for the monitored group, and 0 of 241 patients or 0 per cent for the auscultated group) was of borderline significance with a P value of 7.20 Total
23 138 161
Venous: ~7.25 >7.25 Total *A
Table XII. Apgar 1 1:
Apgar A M
5:
*A.=
180
9.17 9.02 Auscultated
0.8572
Apgar 5 minute: 57 >7
12 2% 234
(241):
(
Total
0.2516 *A
scores, 1 and 5 minute
7.88 7.74
Apgar 1 minute: 57 >7 Total
135
M = monitored.
Mean
SE.
(483 patients) 1
0.09 0.011
Table
= Auscultated;
XIV.
Infant
scores (483 patients) A*
M
P vale
62 179 241
70 -172 242
0.5236
5 22 241
13 229 242
0.085
M = monitored.
neonatal
indices (483 patients)
Pvalw
0.260
0.05 0.07 M = monitored
Apgar
P value
25
18 217 235
= Auscultated;
Apgar A* M
M
XIII.
0.0944 (242).
Intensive-care Temperate
ment of uterine contractions would be a superior method of intrapartum evaluation. The data are more readable, reproducible, and complete than periodic auscultation of the fetal heart tones. Numerous centers in recent years have cited improved perinatal outcome among patients monitored compared to auscultated patients or to the premonitoring era. However, in the present investigation comparing the monitored to the auscultated patient. the over-all perinatal outcome in high-risk pregnancies was not improved with the use of monitoring techniques. There are a number of potential difficulties in the methods and analysis of this study. In evaluating the efficacy of intrapartum electronic monitoring, various problems are inherent. First, there is a lack of uniformity in terminology and methods of interpretation. Second, interpretation of various heart ratt patterns changed as more information has appeared over a relatively short time span. Finally, there is frequently disagreement between investigators as to the significance of various fetal heart rate patterns and patient management. One might conclude that the interpretation of fetal heart rate patterns is not an exact science. It is difficult to select appropriate end points in evaluating perinatal outcome. The most clearly defined is perinatal death but, with present rates so low in this country, especially for term infants, very large numbers of patients are needed to demonstrate any real difference. Apgar scores were once thought to be a good indicator of fetal well-being, but longitudinal
nursery abnormalities
Jaundice Lethargy Seizures Jitteriness
Spontaneous respiration Need to intubate Intermittant *A
positive
= Auscultated
315
pressure (241);
at 2 minutes
M = monitored
A*
M
28
35
7; 21 2 9 4 4 0
7: 19 2 11 7” 5
(242).
studies have recently shown relatively poor correlation with neurologic testing at several years of age. Also, 5 minute Apgar scores have been dramatically improved with the present active resuscitation of the infant by trained physicians. Thus, the number of babies with low 5 minute scores is so low that very large numbers of patients are needed to show the effectiveness of a new method of care. Cord blood gases have also been used as end points in evaluating infant outcome. Their correlation with long-term infant outcome is not known. The pH determination has seemed the most useful but in this study low Apgar scores correlated with low pH values in only half of the cases in the preliminary evaluation. When utilizing the nursery course as an end point, it is obvious that postnatal events need not be related to intrapartum stress per se but these could result from other factors in the antepartum, intrapartum, and postnatal course. Finally, the infant’s longitudinal course over several years was not recorded in this investigation. When such a study is contemplated, it should include: socioeconomic, racial-genetic, anteparturn, intrapartum, postnatal, and other variables which make the final interpretation of this end point difficult and time consuming. There is an apparent trend in the present study for the monitored patients to develop more ominous patterns in the early first stage of labor. When the
316
Haverkamp et al
whole labor is evaluated, this trend is no longer apparent. Actual intrapartum jeopardy is difficult to document because of the problem in evaluating the results of many hours of tracings. The patterns may be nonreassuring for various periods of time and then become normal. There are subtle, less obvious factors involved in the actual care of laboring patients which could influence infant outcome. In this study, for example, the patients who were auscultated had individualized nursing care with one of the project nurses at the bedside almost continually. Very close physical contact with the patient was necessary for the nurse to auscultate fetal heart tones adequately. This was not true to the same degree with the monitored group. Nursing attention to the gravida with respect to maternal comfort. emotional and “laying on of’ hands” could have a support. significant impact on the fetus. ‘41~0, despite the facr that a monitor was attached to the patient, the machinerv was not at the bedside but in the hall. Patients who have a monitor ad.jacent to their bed are often bothered and stressed by flashing light, the sound produced with each fetal heart beat. and hearing or seeing decelerations even when they are benign. The authors have the impression that the reassuring psychological atmosphere created by personal nurse interaction and the absence of the recording machine in auscultated patients contributed to the excellent infant outcome in auscultated patients. One of the principal observations in this study was the striking increase in cesarean sections performed for fetal distress in the monitored group. This provides evidence that the electronic fetal monit,or is associated with an increased section rate and this without apparent Improvement in fetal outcome when compared with an auscultated group. On review at the conclusion of the study. the investigators felt that two of 18 of these would not have been done today with newer knowledge of fetal heart rate patterns. ‘Thus it would appear by the measured infant outcome that some of these cesarean sections arc unnecessary. There was excellent over-all correlation of interpretation of fetal heart rate tracings with the independent reviewers. There was. at times, disagreement with respect to use of the tracings as the sole criteria for performing cesarean sections for fetal distress. It is our conclusion that the total clinical picture of the high-risk gravida must be considered in proper management of these patients. There were cases in which multiple problems existed before and during labor that were accompanied by ominous tracings which led the investigators to decide in favor of cesarean sections. It is important to consider fetal monitoring as one of
June 1, 1976 Am. j. Obstet. Gynecol.
many clinical measures that can be used to help evaluate a given labor but good clinical judgment encompassing all factors must be used in arriving at the optimal mode of managing each individual patient. Within the study patients, the postpartum infection rate was significantly higher in the monitored group (13.2 per cent) in contrast to auscultated patients (3.4 per cent). Although much of this is believed due to the increased number of cesarean sections performed in the former. the incidence remains higher when abdominal deliveries are excluded. Such a difference in the prevalence of endometritis between the two groups delivered vaginally remains unexplained. The excellent. outcome of the study infants, regardless of rnonitored or auscultated, among a high-risk group of pregnancies and of low socioeconomic statuh, is rather striking. There were no intrapartum deaths and a perinatal mortality rate of 6.2 per 1000. ‘Thr study patients’ superior results are due possibly co cxcellencc of. detailed care, but this could also reHect the exclusion of intrapartum deaths that occurred before the patient’s arrival at the hospital and the deaths in very small premature infants weighing less than 1,500 grams, who were excluded frorn the study. The latter figures contribute heavily to over-all perinatal mortality rates. The excellent outcome in the auscultated infant does not mean that close attention need not be paid to the laboring patient. especially the high-risk individual. This study had a one-to-one nurse-patient ratio with rigidly timed auscultations by trained clinical nurses. Auscultation of fetal heart tones every 1 to 2 hours on ;i busy labor floor. as one not infrequeritlv sees, is inadequate observation of the laboring patient. Another important consideration germaine to this discussion is the time, knowledge, and expense necessary to keep the monitoring equipment functional. It has been our experience that it is necessary to have trained electronic personnel to make on the spot adjustments and repairs. Obstetric units without this capability ma\; experience mechanical problems that will interfere with their intrapartum surveillance b\ monitoring. The apparent lack of improvement in perinatal outcome in high-risk pregnancies by the use of the electronic fetal monitoring in this study in comparison to auscultation is unexpected, when considering the current opinion expressed in the world literature. Although monitoring is a helpful adjunct in observing a labor, other ways including auscultation may turn out to be adequate, especially in smaller hospitals where procurement and proper use of sophisticated monitoring equipment may not be feasible. Further. ueil-
Continuous FHR monitoring in high-risk pregnancy
Volume 125 Number3
conducted studies on the value of electronic monitoring need to be carried out before large amounts of money and time are spent, perhaps unnecessarily. The over-all findings of this study in both groups of patients plus the excellent perinatal outcomes in a group of high-risk pregnant patients make it appear that it may be the staff, both nursing and medical, ant1 the facilities that are important in achieving an optimal outcome rather than the use of electronic monitoring per se.
317
The authors wish to thank Drs. E. Stewart Taylor and Watson Bowes of the University of Colorado for their encouragement and support of this study. We wish to recognize the constructive criticism of this project by Drs. Roger Freeman and Robert Resnick. We are indebted to Mrs. Cherri Taylor and Mrs. Vera Drose for their skilled technical assistance.
REFERENCES 1. Anonymous: Is fetal monitoring worthwhile? Br. Med. J. 1: 515, 1971. C. A., and Roberts, 2. Beard, R. W., Filshie, G. M., Knight, G. M.: Intensive care of high risk fetus in labour, J. Obstet. Gynaecol. Br. Commonw. 78: 865, 1971. 3. Gabert, H. A., and Stenchever, M. A.: Continuous electronic monitoring of fetal heart rate during labor, AM. J. OBSTET. GYNECOL. 115: 919, 1973. 4. Kelly, V. C., and Kulkarni, D.: Experiences with fetal monitoring in a community hospital, Obstet. Gynecol. 4: 818, 1973. fetal monitoring, 5. Paul, R. H., and Hon, E. H.: Clinical AM.J.OBSTET.GYNECOL. 118:529, 1974. 6. Paul, R. H.: Clinical fetal monitoring. Experience on a large clinical fetal monitoring, AM. J. OBSTET. GYNLCOL.. 113: 573, 1972. 7. Beard, R. W., Brudenell, F. M., Feroze, R. M., and Clayton, S. G.: The significance of the changes in the continuous fetal heart rate in the first stage of labour, J. Obstet. Gynaecol. Br. Commonw. 78: 882, 1971. 8. Saling, E. Z., and Dudenhausen, J. W.: The present situation of clinical monitoring of the fetus during labor, J. Perinatal Med. 73: 144, 1973.
Discussion DR. JOHN
S. GILLAM,
Des
Moines,
Iowa.
Dr.
Haver-
kamp and his associates, at the risk of critical analysis from both the relatively uninformed, such as myself and the highly informed in maternal and neonatal physiology, have not supplied the answer to the critical question raised by many for years. We needed to know the results of a well-conceived blind study demonstrating the efficacy of continuous electronic fetal monitoring in reducing the perinatal mortality. In the conception of such a study, the fetus needed to be protected. I feel that in this study, even though blind, the fetus had certain advantages over most of being protected by the continuous and close surveillance of a competent nurse. There is not one of us who does not appreciate the value of competent people. I can find no fault with the protocol of this study. The results imply that even in this high-caliber tertiary-care center, too many cesarean sections were done in the interest of the fetus and I agree. The text leaves
one
with
“high-risk” group, fetus is considered
a comfortable
feeling
that
in
this
the survival and adequacy of the the primary responsibility. At least
9. Shenker, L.: Clinical experience with fetal heart rate monitoring on one thousand patients in labor, AM. J. OBSTET.GYNECOL. 115: 1111. 1973. 10. Shenker, L., Post, R. C., and Seiler, J. S.: Routine electronic monitoring of fetal heart rate and uterine activity during labor, Obstet. Gynecol. 46: 185, 1975. 11. Wood, C.: Difficulties in fetal heart rate monitoring, Int. J. Obstet. Gynecol. 10: 176, 1972. 12. Hon, E.: The present status of electronic monitoring of the human fetal heart, Int. J. Obstet. Gynecol. 10: 191, 1972. 13. Hon, E., Zanni, D., and Quilligan, E. J.: The neonatal value of fetal monitoring, AM. J. OBSTET. GYNECOL. 122: 508, 1975. 14. Beard, R. W.: The effect of fetal blood sampling on cesarean section for fetal distress, J. Obstet. Gynaecol. Br. Commonw. 75: 1291, 1968. 15. Goodwin, J. W., Dunne, J. T., and Thomas, R. W.: Antenartum identification of the fetus at risk, Can. Med. As&. J. 101: 458, 1969. 16. Benson, R. c., Shubeck, F., Deutschberger, J., Weiss, W., and Berendes, H.: Fetal Heart rate as a predictor of fetal distress, Obstet. Gynecol. 32: 259, 1968.
the high section rate did not alter this, and the obligation of a “good start” has been fulfilled. With this accolade for an outstanding effort, let us now discuss mostly unanswered issues raised. The difference in numbers of abnormal patterns in early labor
between
the
two
groups,
if
unchanged
by
positional changes, remains unexplained. Some’ suggest fetal scalp blood-PH (FSB-PH) be done at the time of insertion of fetal scalp electrode. This would seem especially appropriate for prematures, or intrauterine growth-retarded fetuses. This FSB-PH, or other methods referred to later, utilized early in labor might shed light on these differences. The differences in morbidity between the purely monitored and the nurse-monitored patients is interesting. Others have noted it between monitored and unmonitored explanation. This study has shown another
without positive-
but unexplained-difference that can no longer be attributed to EFM techniques, since both groups had this. Perhaps Dr. Haverkamp’s suggestion regarding a pleasant nurse at the bedside, in the absence of a beeping monitor, merits consideration. It would seem that the cord blood studies would be
318
Haverkamp
June
et al.
enlightening, but the normals in both groups overshadow relevant results, it appears. Have the two groups of cesarean sections alone been compared? Perhaps even more significant would be the studies of the 18 monitored and three unmonitored where the sections were done for fetal distress, but, 1 presume, the numbers are too small to compare. The authors have repeatedly said that perhaps EFM should not be used as the basis for interference in the course of labor in high-risk patients, since the outcome was the same with EFM and competent nurse monitoring. But either of these relatively expensive methods, especially EFM, can be used as an alerting factor for considering the use of FSB-PH. At Broadlawns Polk County Hospital, other than for socioeconomic reasons, one third of our patients are in the “high-risk” clinic. Thirty per cent of all patients are monitored, but insufficient equipment deters us from monitoring the 50 per cent who should be. For the two years we have had EFM, our primary cesarean section rate has risen from 4.3 to 6.4 per cent, but in this same time. our attitudes toward breech presentations, prolonged labor, or membrane rupture, and cephalopelvic disproportion have become more conservative, resulting in an increase in the cesarean section rate for these problems. The monitored FHR abnormalities required support of FBS-PH determinations to justify interference. Our perinatal mortality rate has dropped from 21.2 to 12.4 per 1,000 live births in this same 2 yeal period. updating the work of many befort Recent reports,‘-” them, have recently shown that, by judging EFM tracings by currently acceptable criteria. only approximately one third of infants showing late deceleration with or without variable decelerations will show FSB-PH samples which would suggest the need of interference. Each in his own way has shown that TSA (the total area under the FHR baseline) whether measured by computer’ or the corometric “corallar\ overlay”’ can perhaps give a much higher correlation between significant FHR depression and the still ultimate FSB-PH. More work needs to be done on beat-to-beat variability. Thus. il is apparent thar Dr. Haverkamp and associates have settled some questions and raised others: (1) identifying high-risk patients and providing them with a perinatal environment for total care are obligatory; (2) the use of EFM is one of the valuable adjuncts, perhaps not yet fully developed, but without FSB-PH and newly emerging tools, it alone does not .justify interference in the normal course of labor; and (3) the questions of early labor FHR abnormalities and puerperal morbidity differences need, if possible, to be answered. In view of their well-demonstrated capabilities to conduct careful studies, we should all encourage them to conrinue their efforts, incorporating new modalities. It seems likely that their cesarean section rate-and possibly their perinatal mortality rare will be reduced.
I. 1976
Am. J. Ohstet. Gynecol.
REFERENCES
1. Tejani, N., Mann, L. I., Bhakthavathsalan, A., and Weiss, R. R.: Correlation of fetal heart rate-uterine contraction patterns and fetal scalp blood pH. In press. 2. Lowelsolm. R. I., Yeh, S. Y., Forsythe, A., and Hon, E. H.: Computer assessed fetal heart rate patterns and fetal scalp pH, Obstet. Gynecol. 46: 190, 1975. 3. Hon, E. H.. Zannini, D., and Quilligan, E. J.: ‘l’he neonatal value of fetal monitoring, AM. J. OBSTET. GYNECOL. 122: 508, 1975. DR. MORTOK A. STENCHEVER, Salt Lake City, Utah. This paper brings up a number of considerations with respect to electronic fetal monitoring. The first significant point to be made should involve the consideration of whether indeed the monitored and unmonitored groups were similar. Although the authors have pointed out that they were similar in a number ot parameters, it is difficult to lump all high-risk pregnancy patients into one group. For instance, high-risk scores are ,given to patients for a variety of reasons. Patients with similar scores may have entirely different diseases with entirely different prognoses with respecl to fetal outcome. The fact that the groups may IIOL be cotnparable is brought out by the findings that there were indeed more patients with significant late deceleration and serious prolonged variable deceleration patterns in the monitored group than there were in the unmonitored group. In addition, the monitored group had a greater postpartum infection rate than did the unmonitored group. Since both groups were exposed to the scalp electrode and the intrauterine catheter, the mechanics c)f monitoring cannot be implicated, and one ~.ouid have to suspect that there was a real tlif-ferencc between the two groups of patients. 111 addition, there was a somewhat larger number of premature infants; that is, infants delivered at 33 weeks’ gestation or earlier in the monitored group (seven) than in the unmonitored group (two) and of post-date patients in the monitored group (23) a\ opposed to the unmonitored group (20). While none oI’ these differences lend themselves to anv statistical significance, cumulatively they may explain some of the variances norctl. The next m+r point to consider is why the cesareart section rate \vas so much higher in the monitored group than iu the unmonitored group. M’as it real11 due to the information derived bv fetal monitoring or was it rather due to the fact that the groups tcere indeed different? I suspect that to a large extent it was due to the differences. Had the tracings of the unmonitored group been followed and decisions as to the performance of cesarean sections made because of‘ these, it would seem from the tracing patterns rhat cesarean section rate would have indeed been lower ill this group. Again, it would seem that the two groups were not comparable with respect to abnormal trarings, although again the numbers are small enough that the differences may not lend themselves to statistical significance. ‘Fhe increased number of late
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deceleration patterns seen in the monitored group could possibly account for the increased number of low Apgar scores at 5 minutes in this group. We have found, as have others, that about 10 per cent of babies monitored have late deceleration patterns, and these are frequently related to low 5 minute Apgar scores, being patterns signifying placental insufficiency. Pla.. cental insufficiency is a problem which may be present long before labor, therefore leading to chronically depresssed babies. At the University of Utah College of Medicine we have monitored all pregnancies that could be monitored for the past 4 years. We have followed the nomenclature of Hon and have used fairly standard procedures for treating fetal distress when it occurs and for instituting delivery when the abnormal pat-, terns are not correctable. Although the first year of our study (1971) was primarily an observation year, the aggressive management of labor has been part of our program for the last 3 years. When comparing these 3 years with our first year, we find a decrease in low Apgar scores (6 or under) at 1 minute by approximately 50 per cent and a modest decrease in the number of low Apgar scores at 5 minutes. We have had no intrapartum fetal deaths during the past 3 years with the exception of those babies who were either grossly immature or suffering from congenital malformations. During this time our primary cesarean section rate because of fetal distress has been approximately 3 per cent. Our primary cesarean section rate has risen during the past 4 years, but this has been secondary to a complete change in attitude toward the care of patients in labor and an increase in the number of high-risk pregnancies we are seeing at our institution. During our 4 years of experience we have noted that approximately one third of our patients show variable deceleration patterns and 10 per cent show late deceleration patterns. These patterns have correlated very well to the findings at the time of delivery, in that the vast majority of variable deceleration patterns have been associated with some type of cord compromise. and three fourths of the late deceleration patterns have been related to placental insufficiency of one sort or another. We have found the monitoring patterns of great assistance in following these babies in labor and have noted the greatest reduction in the number of low Apgar scores in those babies with variable deceleration (cord complication) patterns. We have made some inroads in reducing the number of low Apgar scores in our late deceleration (placental insufficiency) group, but nothing as significant as with the variable group, again pointing to the fact that these problems are more chronic in nature. I would agree with the author that careful monitoring of the fetus by any means will improve the outcome. It should significantly decrease or eliminate the number of intrapartum deaths which occur on a service and should pick up fetal distress problems at an earlier period in time. Electronic fetal monitoring has
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made it possible to follow a number of patients in labor more closely and to indeed act as an early warning mechanism for the distressed baby. If a hospital has the personnel to place a nurse or technician constantly at the mother’s bedside, then this might indeed replace fetal monitoring to some extent. There is no doubt that the presence of a monitor on a service improves the care of the patient in labor in most institutions’ experiences. I would like to take exception to the statements of the authors that many patients are upset by the presence of a monitor at the bedside. We have found in our experience that patients are indeed reassured by the flashing lights and the dials, probably because they realize that the staff is carefully watching the baby’s progress because of the apparatus. It would thus seem that by any mechanism, careful observation is the key to better outcome on an obstetric service, but electronic monitoring is an inexpensive, efficient, and accurate means of accomplishing this. DR. BILL QUILLAN, Fort Belvoir, Virginia. Would the author comment on the positioning of the patient who was monitored and the position changes required? Also, were there differences between those persons monitored and the unmonitored population in the amount of anesthesia used or the frequency of use of anesthesia? Could differences in use or amount contribute to the cesarean section rate due to druginduced changes in fetal heart rate or hypotensive induced changes in the fetal status? DR. JACQUES F. Roux, Montreal. Canada. When I was in Cleveland, we did a similar study and five years ago we’ discussed data which supported the thesis of Dr. Haverkamp. The main reason for which there is some discussion today is the fact that we all have difficulty in interpreting reliably the changes in fetal heart rate. This is well demonstrated in Dr. Cibil? paper. He showed how difficult it is to evaluate clinically changes in fetal heart rate in small-for-dates infants and during postmaturity. I believe that the increase in manpower alone with monitoring will decrease perinatal deaths because the supervision of labor is more thoughtful. I would ask Dr. Haverkamp if he thinks that his study could ever be improved and redesigned, using the fetal scalp pH in suspicious cases. That might improve his data. REFERENCES 1. ROUX, J. F., Wilson, R., Yeni-Komshian, H., Jassani, M., and Jordan, J.: Labor monitoring: a practical experience, Obstet. Gynecol. 36: 875, 1970. 2. Cibils, L. A.: Clinical significance of fetal heart rate patterns during labor. II Late decelerations, AM. J. OBSTET. GYNECOL. 123: 473, 1975.
DR. HAVERKAMP (Closing). Dr. Stenchever questioned the comparability of the two patient study groups. We randomly selected these patients and did everything possible to insure randomization. Statistical
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comparisons between the two groups showed no difference in areas of race, age, parity, tnarital status, risk scores. reasons for inclusion in the study, etc. Over all we noted that there wet-e ominous FHK patterns in 30 of the auscultated and 39 of the electronicallv monitored patients. Again, this is not ;I statistically significant difference. However, there is an unexplained difference in ominous patterns in the early first stage of labor at less than 5 cm. difference. We do not know \vh\: there uas a difference in the infection rate among vaginal deliveries-higher in the tnonitored group. Perhaps the monitor made the examiner do tnore vaginal examinations. We just are unable to explain this trend. Dr. Stenchever alludes to a possible improvement in perinatal mortality rates and IOU i\pgar scores in his institution by recognizing fetal distress with monitors. We and many other institutions have noted improved perinatal mortality rates over the last several years but whether this is due to monitoring or multifactoral (antenatal testing, therapeutic abortion, increased
June 1. 1976 Am. J. Obstet. Cynecol.
obstetrical surveillance, improved neonatal nurser\ survival) is unknown. I think there are too many othelfactors that can change outcomes in comparing several year periods unless you have matched study groups. The position of the laboring patients tended to be OII the left side, especially if there were FHR abnormalities or any special concerns on the part of the physician in charge of labor. The type of anesthesia showed a significant dit’ferencc due to the increase in USCof general anesthesia in the electrically monitored group. ‘This USC of general anesthesia was due to the increase in cesarean sections in this group. 1 very much appreciate Dr. John Gilliam’s comments and we will be incorporating use of scalp pH sampling in a future study. In this future study, we will be following high-risk patients in labor by three methods in intrapartuni evaluation: (1) auscultations of fetal heart tones, (2) electronic FHR monitoring, and (3) electronic FHR monitoring with appropriate fetal scalp sampling and comparing the outcotnes.
