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Intraparturn Fetal Monitoring: One Year’s Experience at a Canadian Teaching Hospital DONA L . M . STEVENS, RN, EDITH K . PARKER, RN, and LEOJ. PEDDLE, MD, FACOG A report of activities in the fetal monitoring unit of a university teaching hospital for the year 1974 is presented. It is shown that significant steps toward optimal reduction of perinatal morbidity and mortality were taken.

The Fetal Monitoring Unit at St. Boniface General Hospital was ?nitiated as a service program in the fall of 1972 and undergoes continuing development. At present, three Hewlett-Packard Fetal Monitors are in use. Each monitor has five components: phonocardiography, ultrasound, electrocardiography for measuring fetal heart rate, tocodynamometer, and a direct pressure mechanism for measuring uterine contractions. The purpose of this report of the fetal monitoring activities for 1974 is to provide an ongoing audit of activities within the unit. It is believed that such an audit is essential as a guide to the appropriate application of new methods of fetal surveillence in order that optimal reduction of perinatal mortality and morbidity may be achieved. It will become apMarch/April 1976 JOGN Nursing

parent from this statistical survey that significant steps in this direction are being taken.

STATISTICAL SURVEY Electronic Fetal Heart Rate Monitoring In 1974, of 2727 total deliveries at St. Boniface, 1003 (36.7%)pregnancies were monitored electronically. Although high-risk pregnancies were concentrated in this group, the service was extended to normal labors if the monitor was free at the time. Most patients were monitored either by external methods (53%,or 536) or by mixed methods involving scalp electrode and tocodynamometer (46%,or 458). Only 9 were monitored exclusively by internal methods. 39

Table 1. Indications for Monitoring in 1003 Patients

Indication Syntocinon induction/ augmentation Epidural anesthesia Hypertensive disorders of pregnancy Prolonged pregnancy (+ 42 weeks) Prolonged labor (+ 24 hours) Meconium passage Fetal heart rate irregularity on auscultation Breech presentation Antepartum hemorrhage Prematurity Diabetes mellitus Rhesus isoimmunization Previous stillbirth or neonatal death Intrauterine growth retardation Anemia Previous uterine scar Miscellaneous TOTAL


No. of patients

Percent of total indications



Patterns and changes




129 124

10.4 10.0



No. of occurrences

Percent of patients



12.9 12.4

Normal (no baselinel periodic changes) Moderate bradycardia




Pronounced bradycardia







Loss of beat-to-beat var iabiI ity



Periodic accelerations


Early decelerations

85 27 271 304

3.8 8.5




120 28

9.7 2.3

12.0 2.8

56 45 86 16 8 11

4.5 3.6 6.9 1.3 0.6 0.9

5.6 4.5 8.6 1.6 0.8 1.1




2 19 143 1242

0.2 1.5 11.5

0.2 1.9 14.3

The various indications for fetal monitoring are listed in Table 1. Since some patients had more than one indication, the total number of indications exceeds the number of patients monitored. The frequency of various patterns and changes detected by the monitor is outlined in Table 2. It is shown that the most common deceleration was, as expected, variable deceleration-in 271 cases (27%).This is the pattern most easilv corrected bv positional changes Bnd is also thk pattern that can lead to overreaction

(120-100) (100) Moderate tachycardia

(1 60-180) Pronounced tachycardia

(1 80)

Late decelerations Variable decelerations Tracings poor (difficult to interpret) TOTAL

and unnecessary cesarean section. It is in this area that fetal blood sampling has its greatest application. Fetal Blood Sampling Fetal blood sampling, involving the skills of specially trained nurses, was introduced as a pilot project in July 1974. A total of 40 samples were taken from 25 patients during the first 6 months of this program, with samples per patient ranging from 1 to 6 with an average of 1.6 samples per patient. Indications for sampling fetal

Table 3. Indications for Fetal Blood Sampling in 25 Patients


No. of patients

Normal fetal heart rate tracing Early deceleration Late deceleration Variable deceleration Decreased beat-to-beat variability Acceleration periodic Bradycardia Tachycardia Meconium

2 2 3 10 4 1 1 2 0


Table 2. Monitor Baseline Patterns and Periodic Changes in 1974 for 1003 Fetal Monitoring Subjects

2.7 27.0 30.3

1037 blood are listed in Table 3; a tabulation of fetal blood pH and Apgar scores, in Table 4. It should be noted that the indications for blood sampling are situations which in the past have lead to surgical delivery. Assurance of stable fetal condition as indicated by high Apgar scores in babies with normal pH values would be expected to lead to a reduction of such deliveries. Oxytocin Challenge Tests Table 5 outlines the experience in the Fetal Monitoring Unit in 1974

Table 4. Comparison of Fetal Blood pH Values and Apgar Scores in 25 Patients

Profile of Apgar Scores at 5 minutes Ph values

7.35 7.25-7.35 7.20-7.25 7.10-7.20






3 14 1 I

Technical failures = 5

March/April 1976 JOGN Nursing

Table 5. Data on Oxytocin Challenge Tests in 32 patients Table 6. Comparison of Cesarean Section Rates In Monitored and Unmonitored Pregnancies of First Half No. of tests 40 of 1974 with Those of Last Half of 1974 ~~



No. positive Number negative No n-assessable Mode of delivery Vaginal Lower segment cesarean section Unknown Outcome Apgar score higher than 7 Unknown

3* 32 5 21 8 3 29 3

Total deliveries Cesarean sections Percent of total Monitored deliveries Cesarean sections Percent

* Two subsequently had normal tracings during labor and went to spontaneous vaginal delivery with Apgar Unmonitored deliveries scores of 9 and 10. One subsequently had a negative Cesarean sections OCT but was delivered by lower segment cesarean secPercent tion because of diabetes mellitus-Apgar score, 9.

with oxytocin challenge tests. These findings offer further support for our current belief that a negative oxytocin challenge test is reassuring of a stable intrauterine milieu. However, a positive test does not necessarily mean that the fetus is in jeopardy but merely tells the obstetrician that he cannot be reassured by this method. Cesarean Section Rates Many fetal monitoring experts have claimed the lowering of cesarean section rate as a result of the introduction of fetal heart rate monitoring. However, as published by Koh et d.,l from a series from this hospital in 1973, the cesarean section rate in monitored patients was 22%. This was one of the reasons for the initiation of the fetal blood sampling program in 1974. The overall cesarean section rate at St. Boniface General Hospital in 1974 was 12.6%(343 of 2727 deliveries). The rate for the year in the monitored group of patients was 19% (190 of 1003); and in the unmonitored group, 8.9% (153 of 1724). An interesting trend becomes evident, however, when one compares the cesarean section rate of the second 6 months of 1974 with the first 6 months (Table 6). Note that the cesarean section rate in the monitored group of patients dropped from 24.2% in the first half of 1974 to 14.8%in the second half. This reduction is statistically significant at the P March/April 1976 JOGN Nursing

= 0.05 level (xz = 3.74). While it is tempting to attribute this decrease to the introduction of fetal blood sampling, the reduction is far more likely to be multifactorial, including continuing education of medical and nursing staff, increased familiarity with monitor tracings, introduction of specially trained monitor nurses into the unit, and finally, availability of a more sophisticated method to delineate fetal distress, i . e . , fetal blood pH, Poz, and Pcoz.

First 6 months

Last 6 months

1307 181 13.8 447 108 24.2

1420 162 11.4 556 82 14.8

860 73 8.5

864 80 9.3

Perinatal Mortality Perinatal mortality rates can frequently be misleading because of varying definitions. This problem is illustrated in the previously published perinatal statistics for St. Boniface for the years 1972, 1973, and 1974. Depending on the definition used, perinatal mortality for St. Boniface General Hospital for the year 1974 may be quoted as anywhere between 13.2 and 20.8. What-

Table 7. Standard Perinatal Mortality Statistics for St. Boniface General Hospital-1974 ( 5 1000 g, 7 7 days)

Number of stillbirths Number of Neonatal deaths 5 10009 Number of live births 5 l O O O g Standard stillbirth rate per 1000 births Standard neonatal death rate per 1000 births Standard perinatal Mortality rate per 1000 total births Corrected no. of unmonitored stillbirths (12 fetal deaths occurred prior to labor) Corrected perinatal mortality rate for unmonitored births

Total (2721)

Monitored 11014*)

Unmonitored I1 707)

16 20

0 8

16 12



2705 5.9 7.4 13.2

4t 9.3

This figure includes 1 1 sets of twins. hydrocephalics, 1 anencephalic, 1 referral from rural area, with prolonged second stage with hypoxia.

t Two


Table 8. Etiology of Stillbirths and Neonatal Deaths Among 2727 Deliveries Stillbirths ( 5 1OOOg) Congenital anomalies Prolonged second stage with hypoxia Abruptio placenta Preeclampsia and small for dates Placenta previa Diabetes mellitus Unknown Neonatal deaths ( 5 1000 g and 7 7 days) congenital heart disease Other congenital anomalies Hyaline membrane disease Meconium and other aspirations Necrotizing enterocolitis Brain hemorrhage

ever definition is used, it is apparent that perinatal mortality over the past 3 years has shown a steady decrease, in spite of the fact that during this same period the Unit received steadily increasing numbers of high-risk referrals. In an attempt to standardize perinatal mortality statistics, the Society of Obstetricians and Gynecologists of Canada and the World Health Organization have defined standard perinatal mortality as “still-birth and neonatal death weighing 1000 grams or more and occurring within the first 7 completed days of extrauterine life.” Standard perinatal mortality rate is based on 1000 total births of fetuses weighing 1000 grams or more. Table 7 gives standard perinatal mortality calculations for St. Boniface General Hospital for the year 1974, the standard perinatal mortality rate for that year being 13.2. Also outlined in Table 7 are mortalities divided into monitored and unmonitored groups. The orginal statistics for unmonitored patients are biased, in that the 16 stillbirths include 12 who had already succumbed before the onset of labor. Hence, in comparing perinatal outcome in monitored versus unmonitored pregnancies, it is necessary to correct standard perinatal mortality by excluding those cases where the fetus has died prior to labor. Thus, as corrected, the perinatal mortality rate in the monitored patients in 42

16 4 1

Address reprint requests to Dona

L. M. Stevens, RN, Fetal Intensive Care Unit, St. Boniface General Hospital, 409 Tache Avenue, Winnipeg, Manitoba, R2H 2A6 Canada.

3 4 1 1

2 20 3 4 7 4 1 1

1974 was 7.9 compared to 9.3 in the unmonitored group. Insofar as the high-risk group of patients is concentrated in the monitored group, it becomes obvious that the perinatal mortality rate for the monitored group compares favorably with that for the unmonitored group. Causes of stillbirths and neonatal deaths in this series are tabulated in Table 8. Observation of the etiologic factors indicates areas in which further improvement in perinatal health care delivery should be sought. Conclusion This report from the Fetal Monitoring Unit at St. Boniface General Hospital has reviewed the experience in the unit during the past year. The points outlined should guide the way for further refinements of available methods and bring closer the objectives of fetal intensive care. Acknowledgments The authors wish to thank the patients, administration, and staff at St. Boniface General Hospital’s Neonatal and Fetal Intensive Care Units and Labor and Delivery Area for their cooperation in preparing this report. Reference 1. Koh: “Experience with Fetal Monitoring in a University Teaching Hospital.” Can Med Assoc J 112:455, 1975

Dona Stevens, a diploma graduate from Winnipeg General Hospital, has attended fetal monitoring workshops at Women’s Hospital in Los Angeles and in Boston. She has also completed &month courses on high-risk pregnancies and fetal monitoring and advanced obstetrics and has spoken on fetal monitoring at a NAACOG District VI Conference and at a fetal monitoring workshop at Banf, Alberta. She is a member of NAACOG and the Manitoba Association of Registered Nurses and is currently Senior Monitor Nurse in the Fetal Intensive Care Unit, St. Boniface General Hospital, Winnipeg, Manitoba. Edith Parker is Perinatology Supervisor at St. Boniface Hospital, a member of the Manitoba Association of Registered Nurses, and a NAACOG member serving as Vice-chairman of the Manitoba-Saskatchewan Section. Her diploma is from Grace General Hospital and the University of Manitoba. In supervisory positions in maternalchild health for the past 9 years, she has also had experience in the operating room, the emergency department, and the intensive care units. Leo Peddle’s MD is from Dalhausie University, Halifax, Nova Scotia. He is currently Chief of the Department of Obstetrics and Gynecology at St. Boniface Hospital and Associate Professor of Ob/Gyn at the University of Manitoba in Winnipeg. He is a member of -the Manitoba Medical Association, the Society of Obstetricians and Gynecologists of Canada, and ACOG. March/April 1976 JOCN Nursing

Intrapartum fetal monitoring: one year's experience at a Canadian teaching hospital.

research and studies Intraparturn Fetal Monitoring: One Year’s Experience at a Canadian Teaching Hospital DONA L . M . STEVENS, RN, EDITH K . PARKER,...
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