Twin births now occur more often than in prior years, and twin pregnancies complicate 2% to 3% of all births. Planned cesarean delivery (CD) may reduce the risk of adverse perinatal outcomes for twins compared with planned vaginal delivery (VD). This study was undertaken to compare the risk of fetal or neonatal death or serious morbidity after planned CD or planned VD in twin pregnancies.
Eligible women had a twin pregnancy at 320 to 386 weeks’ gestation, with the presenting twin in cephalic presentation and both fetuses alive with an estimated weight of 1500 to 4000 g. Patients were randomly assigned to planned CD or planned VD. Elective delivery by CD or labor induction was planned between 375 and 386 weeks’ gestation. At the time of labor if any contraindication to labor or VD was apparent, CD was performed. Mothers and infants were followed up for 28 days postpartum. The primary fetal/neonatal outcome was a composite of mortality or serious morbidities; the primary maternal outcome was a composite of death or serious morbidity before 28 days. Secondary outcomes included death or poor neurodevelopment of children at 2 years of corrected age and maternal incontinence at 2 years postpartum. Satisfaction with method of delivery, breast-feeding, quality of life, fatigue, and depression were also assessed.
The CD and VD groups included 1398 women (2795 fetuses) and 1406 women (2812 fetuses), respectively. Outcome data were available for 1392 women (2783 fetuses or infants) and 1392 women (2782 fetuses or infants) in the CD and VD groups, respectively. The 2 groups were similar in baseline characteristics. Of women in the CD group, 89.9% had a CD for the delivery of both fetuses, 0.8% had a combined VD-CD, and 9.3% had VD for both twins. Of the 1263 deliveries in the CD group, 748 (59.2%) were done before labor. For women in the VD group, 56.2% delivered both twins vaginally, 4.2% had a combined VD-CD, and 39.6% underwent CD for both twins. Of these 610 CDs, 412 (67.5%) were performed during labor. The frequency of the composite primary outcome did not differ significantly between the CD and VD groups (2.2% and 1.9%, respectively; odds ratio with CD, 1.16; 95% confidence interval [CI], 0.77–1.74; P = 0.49). The 2 groups did not differ in the frequency of maternal composite outcome (7.3% for CD, 8.5% for VD; odds ratio, 0.86; 95% CI, 0.65–1.13; P = 0.29). Neither treatment group showed significant interactions between the primary outcome and parity, gestational age at randomization, maternal age, presentation of the second twin, chorionicity, or the national perinatal mortality in the mother’s country of residence. The second twin was more apt than the first twin to have the primary outcome (odds ratio, 1.90; 95% CI, 1.34–2.69; P < 0.001).
In summary, in women with twin gestations with the first twin in the cephalic presentation, planned CD did not significantly decrease or increase the risk of fetal or neonatal death or serious morbidity compared with planned VD. Although a higher risk of an adverse perinatal outcome for the second twin was found, planned CD did not reduce this risk.
Department of Obstetrics and Gynaecology, Centre for Mother, Infant, and Child Research, Sunnybrook Research Institute, and Department of Newborn and Developmental Paediatrics, Sunnybrook Health Sciences Centre, Program in Child Health Evaluative Sciences, SickKids Research Institute, Dalla Lana School of Public Health, and the Department of Paediatrics, Mount Sinai Hospital, University of Toronto, Toronto, Ontario; Midwifery Education Program and Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, Ontario; Departments of Paediatrics and Obstetrics and Gynaecology, Izaak Walton Killam Health Centre, Dalhousie University, Halifax, Nova Scotia; Department of Obstetrics and Gynaecology and the School of Population and Public Health, University of British Columbia, Vancouver, British Columbia; and Department of Obstetrics and Gynaecology, University of Alberta, Edmonton, Alberta, Canada