7: The Twin Birth Study: a multicenter RCT of planned cesarean section (CS) and planned vaginal birth (VB) for twin pregnancies 320 to 386/7 weeks


      To compare planned CS with planned VB for twins 320/7 to 386/7 weeks, if the first twin is cephalic.

      Study Design

      Prospective RCT. Eligibility: Twins 32 to 38+6weeks, live fetuses, Twin A cephalic, EFW 1500g- 4000g. Exclusion: Fetal reduction at >13 wks gestation, lethal fetal anomaly, contraindication to labour. Delivery planned between 375/7 to 386/7 weeks by CS or inducing labour. Primary composite outcome: perinatal/neonatal mortality and/or serious neonatal morbidity. 2800 patients required to detect reduction of primary outcome from 4% to 2%. power 80%, 2-sided, α error of 0.05. A logistic model was used with generalized estimating equations to account for correlation between babies from the same pregnancy.


      2804 women randomized from 26 countries. 1398 to planned CS vs.1406 to planned VB. There was no significant difference between treatment groups. Fifty seven babies of 2781(2.05%) experienced the primary outcome in planned CS vs.52 of 2782 (1.87%) in planned VB (OR1.098,CI 0.726 -1.663,p = 0.6569). There was no significant interaction between treatment group and parity, GA at randomization, mother's age, presentation of twin B, Chorionicity, and country's PNMR.Twin B more likely to experience the primary outcome (OR=1.895,CI:1.329-2.703, p=0.0003). The interaction between treatment group and birth order was not significant (OR;A=1.239; OR;B=1.030, p=0.6125). 89 9% of the women who planned CS delivered both babies by CS. 60.45% in planned VB delivered at least twin A vaginally. 4% of women in planned VB group delivered twin B by CS following VB of twin A. Women in the planned CS delivered earlier but had no increase in maternal mortality or morbidity compared to planned VB.


      Planned CS in twins at 32-38 week does not decrease (or increase) perinatal/neonatal death or serious neonatal morbidity vs planned VB when the first twin is cephalic.