AbstractsThe Obstetrical Services of the University of California advocate vaginal birth for term infants in the breech position under selected circumstances. Since 1980, external version has been attempted at 37 to 39 weeks of gestation in an increasing number of cases. If the version was unsuccessful, a trial of labor was considered. It is the present authors' hypothesis that the attempt at external version for the term infant in the breech position, followed by a trial of labor for selected patients, is preferable to a policy of routine cesarean section. They believe that their program can be carried out without an increase in fetal morbidity or mortality, and since it will reduce the incidence of cesarean section, at lower cost.To evaluate their hypothesis, the authors reviewed all cases of term infants in breech presentations from 1976 through 1984. Three groups were compared with respect to demographic factors, maternal and fetal outcome, and charges: 1) patients delivered by cesarean section without labor; 2) patients allowed a trial of labor but subsequently delivered by cesarean section; and 3) patients with trial of labor and subsequent vaginal delivery. There were 716 cases of singleton breech presentation occurring at 37 or more weeks of gestational age.Of the 716 breech presentations, only 433 (61 per cent) were identified before the onset of labor. Of these, 171 (44 per cent) underwent an attempt at external version. Eighty-three versions (48 per cent) were successful and 88 (52 per cent) were unsuccessful. Seventy-four (89 per cent) of the 83 women with successful versions had vaginal deliveries, whereas nine women (11 per cent) were delivered by cesarean section for either fetal distress or abnormal labor.Of the 623 patients in whom version was unsuccessful (or was not tried) 379 (61 per cent) were delivered by cesarean section without labor. Two hundred and forty-four women (39 per cent) underwent trial of labor. Sixty-nine of these (28 per cent) ultimately were delivered by cesarean section. The indications for surgery were: abnormal labor in 44 patients (64 per cent), fetal distress in 14 (20 per cent), and cord prolapse in 11 (16 per cent). The remaining 175 women (72 per cent) were delivered vagi-nally. X-ray pelvimetry was performed on 119 of the 244 patients (49 per cent) who were permitted a trial of labor. Of the 623 babies who remained breech, 20 per cent were footling, 72 per cent were frank, and 8 per cent were complete.Data for the 625 patients and their babies were stratified into the three groups outlined above. Antepartum, intrapartum, and postpartum maternal variables and neonatal outcome variables (such as Apgar scores, cord blood gases, birth trauma, admission to intensive care, and perinatal death) were compared among the three study groups.There were no differences among the groups in age, parity, gravidity, height, race, or type of breech. When group 1 was compared with groups 2 and 3 (the vaginal trial groups), the pelvic measurements were found to be significantly smaller in group 1. The estimated fetal weight was significantly greater in group 1. These factors influenced the decision to proceed with cesarean section without labor in women with small pelvic measurements or those thought to be carrying large infants.There were significant differences among the three groups with respect to actual birth weight. The mean weight of babies in group 2 (the failed vaginal trial group) was significantly greater than those in the other groups. There were also differences among the groups with respect to both 1− and 5-minute Apgar scores. In each instance, the group 2 babies fell between those in groups 1 and 3. These findings were placed in clinical perspective by examination of blood gas values of the cord. Although the pH and base excess were significantly higher in the infants delivered by cesarean section without labor, the differences had little clinical significance. The fact that there were no significant differences between group 2 and group 3 suggests that labor rather than the route of delivery has some effect on the blood gas values of the umbilical cord. With respect to birth trauma, there was significantly more of it in infants delivered vaginally than in those delivered by cesarean section. Most of the difference was accounted for by an increased frequency of “bruising” in group 3 infants. There were no significant differences in the incidence of admission to intensive care or of perinatal mortality among the three groups. There were five neonatal deaths: four in group 1 and one in group 2. The cause of death in each case was a congenital anomaly, none of which had been diagnosed before delivery.The estimated maternal blood loss was significantly greater in group 1 than in either of the other two groups, but there was no difference in either the frequency of transfusion or the hematocrit value among the groups. The incidence of endometritis was significantly greater in both groups delivered by cesarean section than in the vaginal delivery group.The length of hospital stay for both mother and newborn was significantly longer when cesarean section was performed. The lengthened stay had a significant effect on hospital charges. It is clear that attempted external version is cost effective, with an advantage of almost $1600 per birth (as of 1985) over a population in which no version is attempted.