Volume 163 Number 3
10. Gimovsky ML, Petrie RH, Todd WD. Neonatal performance of the selected term vaginal breech delivery. Obstet Gynecol 1980;56:687-91. II. Amon E, Sibai BM, Anderson GD. How perinatologists manage the problem of the presenting breech. Am] Perinatol 1988;5:247-50. 12. Gimovsky ML, Willard K, Neglio M, Howard T, Zerne S. X-ray pelvimetry in a breech protocol: a comparison of digital radiography and conventional methods. AM] OBSTET GVNECOL 1985;153:887-8. 13. Kopelman ]N, Duff P, Karl RT, Schipul AH, Read ]A. Computed tomographic pelvimetry in the evaluation of breech presentation. Obstet Gynecol 1986;68:455-8. 14. Shepard M], Richards VA, Berkowitz RL, Warsof SL, Hobbins ]C. An evaluation of two equations for predicting fetal weight by ultrasound. AM] OBSTET GVNECOL 1982; 142:47-54. 15. Federle MP, Cohen HA, Rosenwein MF, Brant-Zawadzki
Vaginal breech delivery with computed tomographic pelvimetry
16. 17.
18. 19. 20.
MN, Cann CE. Pelvimetry by digital radiography: a lowdose examination. Radiology 1982; 143:733-5. Collea]V, Chein C. Quilligan EJ. The randomized management of term frank breech presentation: a study of 208 cases. AM] OBSTET GVNECOL 1980; 137:235-44. Kitzmiller ]L, Mall ]C, Gin GD, Hendricks SK, Newman RB, Scheerer L. Measurement of fetal shoulder width with computed tomography in diabetic women. Obstet Gynecol 1987;70:941-5. Friedman EA, Sachtleben MR. Dysfunctional labor. III. Secondary arrest of dilation in the nullipara. Obstet Gynecol 1962;19:576-91. CoIcher AE, Sussman W. A practical technique for roentgen pelvimetry with a new positioning. Am] Roentgenol Radium Ther Nucl Med 1944;51:207-14. Robertson AW, Kopelman]N, Read]A, DuffP, Magelssen D], Dashow EE. External cephalic version at term: is a tocolytic necessary? Obstet Gynecol 1987;70:896-9.
The incidence of significant fetomaternal hemorrhage in patients undergoing cesarean section Nathalie Feldman, MD, Amanda Skoll, MD, and Baha Sibai, MD Memphis, Tennessee To determine the incidence of fetomaternal hemorrhage in patients undergoing cesarean section, Kleihauer-Betke tests were performed in the immediate postoperative period on 199 parturients. Some degree of hemorrhage was detected in 18.5% of patients, with 2.5% demonstrating >30 ml of fetal blood. Comparison of groups on the basis of indication for cesarean delivery revealed no difference in rates of fetal hemorrhage. Because patients with >30 ml of fetal blood would not be adequately protected from Rh sensitization by the standard 300 fL9 dose of Rh immune globulin, we recommend screening all Rh-negative patients undergoing cesarean section for the presence of significant fetomaternal hemorrhage. (AM J OSSTET GVNECOL 1990;163:855-8.)
Key words: Fetomaternal hemorrhage, Rh sensitization
The widespread use of postpartum and antepartum Rh immune globulin has significantly reduced the incidence of hemolytic disease of the newborn as a result of maternal Rh isoimmunization. However, there remains a small number of patients (0.2% to 1%) who become sensitized at the time of delivery,l perhaps as a result of significant fetomaternal hemorrhage occurring at that time. Because the standard dose of Rh immune globulin (300 f.Lg) covers up to 30 ml of fetal
From the Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, University of Tennessee, Memphis, Memphis, Tennessee. Presented at the Tenth Annual Meeting of the Society of Perinatal Obstetricians, Houston, Texas, january 23-27, 1990. Reprint requests: Baha Sibai, MD, Department of Obstetrics and Gynecology, 853 jefferson Ave., Room E102, Memphis TN 38103. 6/6/22597
hemorrhage! any degree of fetomaternal hemorrhage above this threshold could result in sensitization. Previous studies have suggested several different clinical factors that may increase the risk of significant fetomaternal hemorrhage including forceps delivery, manual removal of the placenta, multiple gestation, fetal distress, and cesarean section.'·7 However, there is no consensus as to which, if any, of these factors can identify a group of patients who should be tested at the time of delivery to quantify the degree of fetomaternal hemorrhage."·g The purpose of this study was to determine the incidence of significant fetomaternal hemorrhage in patients undergoing cesarean delivery at our institution to decide whether routine quantification of fetomaternal hemorrhage was justified to identify patients who require extra Rh immune globulin.
855
856
Feldman, Skoll, and Sibai
September 1990 Am J Obstet Gyneco1
Table I. Clinical characteristics of patients with significant fetomaternal hemorrhage (>30 ml) Patient
J. B.
D. F. M.M. A.G. B. B.
1 3 1 6 3
0 2 0 1 1
Gestational age (wk)
Amount of fetomaternal hemorrhage
Indication for cesarean section
36 41 28 38 38
43.0 37.7 31.2 45.7 48.2
Breech, bicornuate uterus Fetal distress, abruptio placentae? Fetal distress, eclampsia Elective repeat-no complications Fetal distress
Material and methods The E. H. Crump Women's Hospital is a tertiary care center affiliated with the University of Tennessee, Memphis, serving the population of Memphis, western Tennessee, and parts of Arkansas, and Mississippi. The study protocol was reviewed and approved by the Institutional Review Board of the University. The study population consisted of 200 consecutive patients undergoing cesarean section for any indication. In the immediate postoperative period (usually within 1 hour, but occasionally as long as 4 hours post operatively), 5 ml of blood was drawn from the antecubital vein into a vacuum tube containing 0.05 ml of 15% ethylenediaminetetraacetic acid. All samples were then refrigerated until a Kleihauer-Betke acid elution test'° could be performed to quantify the number of fetal cells present. All tests were performed within 24 hours of specimen collection by the same technician. One specimen was lost, leaving 199 patients for analysis. The total amount of fetal blood present in the maternal circulation at the time of sampling was determined by the formula:
Cesarean section was performed for the following indications: elective repeat in 23 (1l.6%), fetal distress in 62 (31.1 %), secondary arrest oflabor-cephalopelvic disproportion in 60 (30.2%), breech or other malpresentation in 19 (9.5%), and other indications including placenta previa, abruptio placentae, fetal anomalies, and active herpes simplex virus infection in 32 (16.1 %). In three cases (1.5%), the indication for cesarean section was unclear. These patients are included in the "other" group for analysis. A total of 162 patients (8l.4%) had no detectable fetomaternal hemorrhage, 27 (13.6%) had between 1 and 25 ml of fetomaternal hemorrhage; 5 (2.5%) had between 25 and 30 ml, and an additional 5 patients (2.5%) had >30 ml offetomaternal hemorrhage detected. Clinical characteristics of the patients demonstrating >30 ml of fetal blood in the maternal compartment are shown in Table I. Table II reveals the degree of fetomaternal hemorrhage by indication for delivery. Rates of significant fetomaternal hemorrhage by subgroup are not statistically different from one another.
Number of fetal cells Number of maternal cells Volume of fetal hemorrhage lO Maternal blood volume (estimate)
Comment The overall rate of detectable fetomaternal hemorrhage in our study populaton was 37 of 199 or 18.6%. Overall, in 2.5% of our patients there was evidence of a larger fetomaternal hemorrhage than would be neutralized by a single 300 ILg dose of Rh immune globulin (i.e., >30 ml).2 In addition, another 2.5% of patients had between 25 and 30 ml of hemorrhage-a group that may be at borderline risk of sensitization if given a single dose of Rh immune globulin. Ness et aP reported an overall rate of detectable fetomaternal hemorrhage of 12.3% in cesarean section patients, with a rate of 2.8% for hemorrhage in excess of 20 m!. Population studies have suggested that 0.6% to 1% of patients have significant fetomaternal hemorrhage detected post partum. S • 9 • 11 It remains unclear whether it is cesarean section itself or the antenatal factors predisposing the patient to operative delivery that result in the observed increase in significant fetomaternal hemorrhage. Pilkington6 found an increased number of fetal cells before delivery in patients who subsequently underwent cesarean delivery, suggesting that the indication for surgery, rather than the procedure
Maternal blood volume was estimated on the basis of maternal weight at the time of admission for cesarean section. Patients were grouped according to amount of fetomaternal hemorrhage detected. In addition, the patients were divided into subgroups by indication for cesarean section to detect any effect of this factor on the incidence of significant fetomaternal hemorrhage. The X2 analysis was performed to compare the rates of significant fetomaternal hemorrhage among subgroups.
Results A total of 199 patients were available for analysis. Gestational age ranged from 26 to 43 weeks, with 156 patients (78.4%) having attained at least 36 weeks' gestation. Rh status was available in 180 patients. Of these, 156 (86.7%) were Rh positive and 24 (13.3%) were Rh negative.
Fetomaternal hemorrhage at cesarean section
Volume 163 Number 3
857
Table II. Breakdown of degree of fetomaternal hemorrhage by indication for cesarean section Amount of fetorrUlternal hemorrhage 1-25 ml
0 ~-.
No.
Repeat Fetal distress Cephalopelvic disproportion Breech Other
18 49 52 15 28* 162
TOTAL
I
%
No.
78.3 79 86.7 78.9 80 81.4
4 7 7 2 7 27
I
25-30 ml
%
No.
17.4 11.3 11.7 10.5 20 13.6
0 3 1 I
0 5
I
>30 ml
%
No.
0 4.8 1.7 5.3 0 2.5
1 3 0 1 0 5
I
%
Total
4.3 4.8 0 5.3 0 2.5
23 62 60 19 35*
*Includes three cases in which indication was unclear.
itself predisposed the patient to an increased fetomaternal hemorrhage. It is routine practice at our institution to deliver the placenta by manual extraction when performing a cesarean section. Although many groups studying the influence of obstetric factors on the incidence of fetomaternal hemorrhage have found manual removal of the placenta to increase the risk,'·7 this has generally been studied after vaginal delivery. It is unclear whether this technique used at the time of cesarean section has any independent effect on the rate of fetomaternal hemorrhage over and above that that may be related to the operative delivery itself. Fetal distress has also been associated in some reports with an increased incidence of significant fetomaternal hemorrhage."" 7 In our study, cesarean section for fetal distress was not associated with any increased risk of significant fetomaternal hemorrhage compared with other indications for operative delivery. In fact, comparison of all the groups failed to reveal any significant difference in detectable hemorrhage or large fetomaternal hemorrhage between the various indications for operation. Although the majority of our patients were Rh positive (86.7%) and therefore not at risk for Rh sensitization, it is unlikely that this factor would alter the amount of fetomaternal hemorrhage occurring at the time of delivery. ABO blood group incompatibility between mother and fetus is known to influence the likelihood of recovering fetal cells in the maternal circulation post partum. 5 • 6 We were unable to confirm the ABO types of a sufficient number of our mother-infant pairs to be able to analyze this factor. If there was a delay in obtaining blood samples, ABO incompatibility would decrease the yield of fetal cells on KleihauerBetke analysis and therefore lead to an overall underestimation of the degree of hemorrhage. However, the fact that all study specimens were drawn within 4 hours of delivery minimizes any possible confounding effect of this factor. The patients who demonstrated between 25 and 30 ml of fetal hemorrhage accounted for 2.5% of our study
population. Because the error in the technique of quantifying fetal cells can be reasonably assumed to be ± lO%, there are patients in this group who would remain at risk for sensitization if administered only one vial of Rh immune globulin. Although the absolute risk of sensitization in these patients is small, an extra dose of Rh immune globulin would be prudent. The Kleihauer-Betke acid elution test is a relatively sensitive test for the quantification of fetal bleeding. 12 However, it is labor intensive and even with careful standardization may result in widely varying results. Despite these drawbacks, it is currently the standard test and is used in the majority of clinical institutions and in published reports. New rapid tests for the detection of fetal cells including enzyme-linked antiglobulin tests" and a rosetting technique with enzymetreated indicator erythrocytes" have been developed. These could be useful for widespread screening, with the Kleihauer-Betke test available for confirmation. In 1984, the American College of Obstetricians and Gynecologists issued a recommendation that all Rhnegative women delivered of Rh-positive infants and in a high-risk category be investigated for quantification of fetomaternal hemorrhage post partum. 15 These high-risk categories included abruptio placentae, placenta previa, cesarean delivery, intrauterine manipulation, or manual removal of the placenta. Our study certainly supports the need for postpartum screening in Rh-negative patients undergoing cesarean section, with administration of extra Rh immune globulin to those who demonstrate excessive fetomaternal hemorrhage. We conclude that in our population of 199 patients undergoing cesarean delivery for all indications, 2.5% had evidence of fetomaternal hemorrhage > 30 ml at the time of delivery and an additional 2.5% had between 25 and 30 ml of hemorrhage. On the basis of these findings, we recommend that all Rh-negative women delivered by cesarean section of Rh-positive infants undergo evaluation for quantification of fetomaternal hemorrhage. This testing should be performed early in the postpartum period to allow
858
Feldman, Skoll, and Sibai
for the administration of the appropriate protective dose of Rh immune globulin. REFERENCES I. McMaster conference on prevention of Rh isoimmunization, September 28-30, 1977. Vox Sang 1979;36:50-64. 2. Pollack W, Ascari WQ, Kochesky RJ, O'Connor RR, Ho TY, Tripodi D. Studies on Rh prophylaxis. I. Relationship between doses of anti-Rh and size of antigenic stimulus. Transfusion 1971; II :333-9. 3. Devi B, Jennison RF, Langley FA. Relationship of transplacental haemorrhage to abnormal pregnancy and delivery. J Obstet Gynaecol Br Cwlth 1968;75:659-66. 4. Knox EG. Obstetric determinants of rhesus sensitisation. Lancet 1968; 1:433-7. 5. Montague ACW, Krevans JR. Tranplacental hemorrhage in cesarean section. AM J OBSTET GYNECOL 1966;95: II 15-8. 6. Pilkington R, Knoz EG, Russell JK, Walker W. Foetalmaternal transfusion and rhesus sensitization. J Obstet Gynaecol Br Cwlth 1966;73:909-16. 7. Li TC, Bromham DR, Balmer BM. Fetomaternal macrotransfusion in the Yorkshire region. I. Prevalence and obstetric factors. Br J Obstet GynaecoI1988;95:Il44-51.
September 1990 Am J Obstet Gynecol
8. Ness PM, Baldwin ML, Niebyl JR. Clinical high-risk designation does not predict excess fetal-maternal hemorrhage. AMJ OBSTETGYNECOL 1987;156:154-8. 9. Lloyd LK, Miya F, Hebertson RM, Kochenour NK, Scott JR. Intrapartum fetomaternal bleeding Rh-negative women. Obstet Gynecol 1980;56:285-8. 10. Kleihauer E, Braun J, Betke K. Demonstration von fetalem haemoglobin in den erthrocyten eines blutausstrick. Klin Wochenschr 1957;35:637. II. Zipursky A. The universal prevention of Rh immunization. Clin Obstet Gynecol 1971; 14:869-84. 12. Scott JR, Waren ski JC. Tests to detect and quantitate fetomaternal bleeding. Clin Obstet Gynecol 1982;25:27782. 13. Leikola J, Perkins HA. Enzyme linked antiglobulin test: an accurate and simple method to quantify red cell antibodies. Transfusion 1980;20: 138. 14. Sebring ES, Polesky HF. Detection of fetal maternal hemorrhage in Rh immune globulin candidates: a rosetting technique using enzyme-treated Rh.Rh. indicator erthrocytes. Transfusion 1982;22:468-71. 15. Prevention of Rho(D) isoimmunization. Technical Bulletin. Washington, DC: American College of Obstetricians and Gynecologists, 1984:79.
10. Gimovsky ML, Petrie RH, Todd WD. Neonatal performance of the selected term vaginal breech delivery. Obstet Gynecol 1980;56:687-91. II. Amon E, Sibai BM, Anderson GD. How perinatologists manage the problem of the presenting breech. Am] Perinatol 1988;5:247-50. 12. Gimovsky ML, Willard K, Neglio M, Howard T, Zerne S. X-ray pelvimetry in a breech protocol: a comparison of digital radiography and conventional methods. AM] OBSTET GVNECOL 1985;153:887-8. 13. Kopelman ]N, Duff P, Karl RT, Schipul AH, Read ]A. Computed tomographic pelvimetry in the evaluation of breech presentation. Obstet Gynecol 1986;68:455-8. 14. Shepard M], Richards VA, Berkowitz RL, Warsof SL, Hobbins ]C. An evaluation of two equations for predicting fetal weight by ultrasound. AM] OBSTET GVNECOL 1982; 142:47-54. 15. Federle MP, Cohen HA, Rosenwein MF, Brant-Zawadzki
Vaginal breech delivery with computed tomographic pelvimetry
16. 17.
18. 19. 20.
MN, Cann CE. Pelvimetry by digital radiography: a lowdose examination. Radiology 1982; 143:733-5. Collea]V, Chein C. Quilligan EJ. The randomized management of term frank breech presentation: a study of 208 cases. AM] OBSTET GVNECOL 1980; 137:235-44. Kitzmiller ]L, Mall ]C, Gin GD, Hendricks SK, Newman RB, Scheerer L. Measurement of fetal shoulder width with computed tomography in diabetic women. Obstet Gynecol 1987;70:941-5. Friedman EA, Sachtleben MR. Dysfunctional labor. III. Secondary arrest of dilation in the nullipara. Obstet Gynecol 1962;19:576-91. CoIcher AE, Sussman W. A practical technique for roentgen pelvimetry with a new positioning. Am] Roentgenol Radium Ther Nucl Med 1944;51:207-14. Robertson AW, Kopelman]N, Read]A, DuffP, Magelssen D], Dashow EE. External cephalic version at term: is a tocolytic necessary? Obstet Gynecol 1987;70:896-9.
The incidence of significant fetomaternal hemorrhage in patients undergoing cesarean section Nathalie Feldman, MD, Amanda Skoll, MD, and Baha Sibai, MD Memphis, Tennessee To determine the incidence of fetomaternal hemorrhage in patients undergoing cesarean section, Kleihauer-Betke tests were performed in the immediate postoperative period on 199 parturients. Some degree of hemorrhage was detected in 18.5% of patients, with 2.5% demonstrating >30 ml of fetal blood. Comparison of groups on the basis of indication for cesarean delivery revealed no difference in rates of fetal hemorrhage. Because patients with >30 ml of fetal blood would not be adequately protected from Rh sensitization by the standard 300 fL9 dose of Rh immune globulin, we recommend screening all Rh-negative patients undergoing cesarean section for the presence of significant fetomaternal hemorrhage. (AM J OSSTET GVNECOL 1990;163:855-8.)
Key words: Fetomaternal hemorrhage, Rh sensitization
The widespread use of postpartum and antepartum Rh immune globulin has significantly reduced the incidence of hemolytic disease of the newborn as a result of maternal Rh isoimmunization. However, there remains a small number of patients (0.2% to 1%) who become sensitized at the time of delivery,l perhaps as a result of significant fetomaternal hemorrhage occurring at that time. Because the standard dose of Rh immune globulin (300 f.Lg) covers up to 30 ml of fetal
From the Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, University of Tennessee, Memphis, Memphis, Tennessee. Presented at the Tenth Annual Meeting of the Society of Perinatal Obstetricians, Houston, Texas, january 23-27, 1990. Reprint requests: Baha Sibai, MD, Department of Obstetrics and Gynecology, 853 jefferson Ave., Room E102, Memphis TN 38103. 6/6/22597
hemorrhage! any degree of fetomaternal hemorrhage above this threshold could result in sensitization. Previous studies have suggested several different clinical factors that may increase the risk of significant fetomaternal hemorrhage including forceps delivery, manual removal of the placenta, multiple gestation, fetal distress, and cesarean section.'·7 However, there is no consensus as to which, if any, of these factors can identify a group of patients who should be tested at the time of delivery to quantify the degree of fetomaternal hemorrhage."·g The purpose of this study was to determine the incidence of significant fetomaternal hemorrhage in patients undergoing cesarean delivery at our institution to decide whether routine quantification of fetomaternal hemorrhage was justified to identify patients who require extra Rh immune globulin.
855
856
Feldman, Skoll, and Sibai
September 1990 Am J Obstet Gyneco1
Table I. Clinical characteristics of patients with significant fetomaternal hemorrhage (>30 ml) Patient
J. B.
D. F. M.M. A.G. B. B.
1 3 1 6 3
0 2 0 1 1
Gestational age (wk)
Amount of fetomaternal hemorrhage
Indication for cesarean section
36 41 28 38 38
43.0 37.7 31.2 45.7 48.2
Breech, bicornuate uterus Fetal distress, abruptio placentae? Fetal distress, eclampsia Elective repeat-no complications Fetal distress
Material and methods The E. H. Crump Women's Hospital is a tertiary care center affiliated with the University of Tennessee, Memphis, serving the population of Memphis, western Tennessee, and parts of Arkansas, and Mississippi. The study protocol was reviewed and approved by the Institutional Review Board of the University. The study population consisted of 200 consecutive patients undergoing cesarean section for any indication. In the immediate postoperative period (usually within 1 hour, but occasionally as long as 4 hours post operatively), 5 ml of blood was drawn from the antecubital vein into a vacuum tube containing 0.05 ml of 15% ethylenediaminetetraacetic acid. All samples were then refrigerated until a Kleihauer-Betke acid elution test'° could be performed to quantify the number of fetal cells present. All tests were performed within 24 hours of specimen collection by the same technician. One specimen was lost, leaving 199 patients for analysis. The total amount of fetal blood present in the maternal circulation at the time of sampling was determined by the formula:
Cesarean section was performed for the following indications: elective repeat in 23 (1l.6%), fetal distress in 62 (31.1 %), secondary arrest oflabor-cephalopelvic disproportion in 60 (30.2%), breech or other malpresentation in 19 (9.5%), and other indications including placenta previa, abruptio placentae, fetal anomalies, and active herpes simplex virus infection in 32 (16.1 %). In three cases (1.5%), the indication for cesarean section was unclear. These patients are included in the "other" group for analysis. A total of 162 patients (8l.4%) had no detectable fetomaternal hemorrhage, 27 (13.6%) had between 1 and 25 ml of fetomaternal hemorrhage; 5 (2.5%) had between 25 and 30 ml, and an additional 5 patients (2.5%) had >30 ml offetomaternal hemorrhage detected. Clinical characteristics of the patients demonstrating >30 ml of fetal blood in the maternal compartment are shown in Table I. Table II reveals the degree of fetomaternal hemorrhage by indication for delivery. Rates of significant fetomaternal hemorrhage by subgroup are not statistically different from one another.
Number of fetal cells Number of maternal cells Volume of fetal hemorrhage lO Maternal blood volume (estimate)
Comment The overall rate of detectable fetomaternal hemorrhage in our study populaton was 37 of 199 or 18.6%. Overall, in 2.5% of our patients there was evidence of a larger fetomaternal hemorrhage than would be neutralized by a single 300 ILg dose of Rh immune globulin (i.e., >30 ml).2 In addition, another 2.5% of patients had between 25 and 30 ml of hemorrhage-a group that may be at borderline risk of sensitization if given a single dose of Rh immune globulin. Ness et aP reported an overall rate of detectable fetomaternal hemorrhage of 12.3% in cesarean section patients, with a rate of 2.8% for hemorrhage in excess of 20 m!. Population studies have suggested that 0.6% to 1% of patients have significant fetomaternal hemorrhage detected post partum. S • 9 • 11 It remains unclear whether it is cesarean section itself or the antenatal factors predisposing the patient to operative delivery that result in the observed increase in significant fetomaternal hemorrhage. Pilkington6 found an increased number of fetal cells before delivery in patients who subsequently underwent cesarean delivery, suggesting that the indication for surgery, rather than the procedure
Maternal blood volume was estimated on the basis of maternal weight at the time of admission for cesarean section. Patients were grouped according to amount of fetomaternal hemorrhage detected. In addition, the patients were divided into subgroups by indication for cesarean section to detect any effect of this factor on the incidence of significant fetomaternal hemorrhage. The X2 analysis was performed to compare the rates of significant fetomaternal hemorrhage among subgroups.
Results A total of 199 patients were available for analysis. Gestational age ranged from 26 to 43 weeks, with 156 patients (78.4%) having attained at least 36 weeks' gestation. Rh status was available in 180 patients. Of these, 156 (86.7%) were Rh positive and 24 (13.3%) were Rh negative.
Fetomaternal hemorrhage at cesarean section
Volume 163 Number 3
857
Table II. Breakdown of degree of fetomaternal hemorrhage by indication for cesarean section Amount of fetorrUlternal hemorrhage 1-25 ml
0 ~-.
No.
Repeat Fetal distress Cephalopelvic disproportion Breech Other
18 49 52 15 28* 162
TOTAL
I
%
No.
78.3 79 86.7 78.9 80 81.4
4 7 7 2 7 27
I
25-30 ml
%
No.
17.4 11.3 11.7 10.5 20 13.6
0 3 1 I
0 5
I
>30 ml
%
No.
0 4.8 1.7 5.3 0 2.5
1 3 0 1 0 5
I
%
Total
4.3 4.8 0 5.3 0 2.5
23 62 60 19 35*
*Includes three cases in which indication was unclear.
itself predisposed the patient to an increased fetomaternal hemorrhage. It is routine practice at our institution to deliver the placenta by manual extraction when performing a cesarean section. Although many groups studying the influence of obstetric factors on the incidence of fetomaternal hemorrhage have found manual removal of the placenta to increase the risk,'·7 this has generally been studied after vaginal delivery. It is unclear whether this technique used at the time of cesarean section has any independent effect on the rate of fetomaternal hemorrhage over and above that that may be related to the operative delivery itself. Fetal distress has also been associated in some reports with an increased incidence of significant fetomaternal hemorrhage."" 7 In our study, cesarean section for fetal distress was not associated with any increased risk of significant fetomaternal hemorrhage compared with other indications for operative delivery. In fact, comparison of all the groups failed to reveal any significant difference in detectable hemorrhage or large fetomaternal hemorrhage between the various indications for operation. Although the majority of our patients were Rh positive (86.7%) and therefore not at risk for Rh sensitization, it is unlikely that this factor would alter the amount of fetomaternal hemorrhage occurring at the time of delivery. ABO blood group incompatibility between mother and fetus is known to influence the likelihood of recovering fetal cells in the maternal circulation post partum. 5 • 6 We were unable to confirm the ABO types of a sufficient number of our mother-infant pairs to be able to analyze this factor. If there was a delay in obtaining blood samples, ABO incompatibility would decrease the yield of fetal cells on KleihauerBetke analysis and therefore lead to an overall underestimation of the degree of hemorrhage. However, the fact that all study specimens were drawn within 4 hours of delivery minimizes any possible confounding effect of this factor. The patients who demonstrated between 25 and 30 ml of fetal hemorrhage accounted for 2.5% of our study
population. Because the error in the technique of quantifying fetal cells can be reasonably assumed to be ± lO%, there are patients in this group who would remain at risk for sensitization if administered only one vial of Rh immune globulin. Although the absolute risk of sensitization in these patients is small, an extra dose of Rh immune globulin would be prudent. The Kleihauer-Betke acid elution test is a relatively sensitive test for the quantification of fetal bleeding. 12 However, it is labor intensive and even with careful standardization may result in widely varying results. Despite these drawbacks, it is currently the standard test and is used in the majority of clinical institutions and in published reports. New rapid tests for the detection of fetal cells including enzyme-linked antiglobulin tests" and a rosetting technique with enzymetreated indicator erythrocytes" have been developed. These could be useful for widespread screening, with the Kleihauer-Betke test available for confirmation. In 1984, the American College of Obstetricians and Gynecologists issued a recommendation that all Rhnegative women delivered of Rh-positive infants and in a high-risk category be investigated for quantification of fetomaternal hemorrhage post partum. 15 These high-risk categories included abruptio placentae, placenta previa, cesarean delivery, intrauterine manipulation, or manual removal of the placenta. Our study certainly supports the need for postpartum screening in Rh-negative patients undergoing cesarean section, with administration of extra Rh immune globulin to those who demonstrate excessive fetomaternal hemorrhage. We conclude that in our population of 199 patients undergoing cesarean delivery for all indications, 2.5% had evidence of fetomaternal hemorrhage > 30 ml at the time of delivery and an additional 2.5% had between 25 and 30 ml of hemorrhage. On the basis of these findings, we recommend that all Rh-negative women delivered by cesarean section of Rh-positive infants undergo evaluation for quantification of fetomaternal hemorrhage. This testing should be performed early in the postpartum period to allow
858
Feldman, Skoll, and Sibai
for the administration of the appropriate protective dose of Rh immune globulin. REFERENCES I. McMaster conference on prevention of Rh isoimmunization, September 28-30, 1977. Vox Sang 1979;36:50-64. 2. Pollack W, Ascari WQ, Kochesky RJ, O'Connor RR, Ho TY, Tripodi D. Studies on Rh prophylaxis. I. Relationship between doses of anti-Rh and size of antigenic stimulus. Transfusion 1971; II :333-9. 3. Devi B, Jennison RF, Langley FA. Relationship of transplacental haemorrhage to abnormal pregnancy and delivery. J Obstet Gynaecol Br Cwlth 1968;75:659-66. 4. Knox EG. Obstetric determinants of rhesus sensitisation. Lancet 1968; 1:433-7. 5. Montague ACW, Krevans JR. Tranplacental hemorrhage in cesarean section. AM J OBSTET GYNECOL 1966;95: II 15-8. 6. Pilkington R, Knoz EG, Russell JK, Walker W. Foetalmaternal transfusion and rhesus sensitization. J Obstet Gynaecol Br Cwlth 1966;73:909-16. 7. Li TC, Bromham DR, Balmer BM. Fetomaternal macrotransfusion in the Yorkshire region. I. Prevalence and obstetric factors. Br J Obstet GynaecoI1988;95:Il44-51.
September 1990 Am J Obstet Gynecol
8. Ness PM, Baldwin ML, Niebyl JR. Clinical high-risk designation does not predict excess fetal-maternal hemorrhage. AMJ OBSTETGYNECOL 1987;156:154-8. 9. Lloyd LK, Miya F, Hebertson RM, Kochenour NK, Scott JR. Intrapartum fetomaternal bleeding Rh-negative women. Obstet Gynecol 1980;56:285-8. 10. Kleihauer E, Braun J, Betke K. Demonstration von fetalem haemoglobin in den erthrocyten eines blutausstrick. Klin Wochenschr 1957;35:637. II. Zipursky A. The universal prevention of Rh immunization. Clin Obstet Gynecol 1971; 14:869-84. 12. Scott JR, Waren ski JC. Tests to detect and quantitate fetomaternal bleeding. Clin Obstet Gynecol 1982;25:27782. 13. Leikola J, Perkins HA. Enzyme linked antiglobulin test: an accurate and simple method to quantify red cell antibodies. Transfusion 1980;20: 138. 14. Sebring ES, Polesky HF. Detection of fetal maternal hemorrhage in Rh immune globulin candidates: a rosetting technique using enzyme-treated Rh.Rh. indicator erthrocytes. Transfusion 1982;22:468-71. 15. Prevention of Rho(D) isoimmunization. Technical Bulletin. Washington, DC: American College of Obstetricians and Gynecologists, 1984:79.
