Fetomaternal hemorrhage during external cephalic version

Objective To estimate the frequency and volume of fetomaternal hemorrhage during external cephalic version for term breech singleton fetuses and to identify risk factors involved with this complication. Methods A prospective observational study was performed including all patients undergoing a trial of external cephalic version for a breech presentation of at least 36 weeks of gestation between 1987 and 2001 in our center. A search for fetal erythrocytes using the standard Kleihauer-Betke test was obtained before and after each external cephalic version. The frequency and volume of fetomaternal hemorrhage were calculated. Putative risk factors for fetomaternal hemorrhage were evaluated by chi(2) test and Mann-Whitney U test. Results A Kleihauer-Betke test result was available before and after 1,311 trials of external cephalic version. The Kleihauer-Betke test was positive in 67 (5.1%) before the procedure. Of the 1,244 women with a negative Kleihauer-Betke test before external cephalic version, 30 (2.4%) had a positive Kleihauer-Betke test after the procedure. Ten (0.8%) had an estimated fetomaternal hemorrhage greater than 1 mL, and one (0.08%) had an estimated fetomaternal hemorrhage greater than 30 mL. The risk of fetomaternal hemorrhage was not influenced by parity, gestational age, body mass index, number of attempts at version, placental location, or amniotic fluid index. Conclusion The risk of detectable fetomaternal hemorrhage during external cephalic version was 2.4%, with fetomaternal hemorrhage more than 30 mL in less than 0.1% of cases. These data suggest that the performance of a Kleihauer-Betke test is unwarranted in uneventful external cephalic version and that in Rh-negative women, no further Rh immune globulin is necessary other than the routine 300-microgram dose at 28 weeks of gestation and postpartum. Level of evidence II.