Timing and mode of delivery for uncomplicated twin pregnancies

Abstract

Objective To investigate the relationship between time and mode of delivery and gestational outcomes in uncomplicated twin pregnancies. Methods A total of 347 women with uncomplicated twin pregnancies who gave birth in First Affiliated Hospital of Sun Yat-Sen University between November 2012 and June 2015 were reviewed retrospectively, including 291 dichorionic diamniotic twin pregnancies (DCDA) and 56 monochorionic diamniotic twin pregnancies (MCDA). The general information, gestational complications, time and mode of delivery, gestational outcomes were recorded and the relationship between time and mode of delivery and gestational outcomes in DCDA and MCDA groups were analyzed. T test, Chi-square, Fisher's exact test and logistic regression analysis were used for statistical analysis. Results (1) The incidence of adverse neonatal outcomes in DCDA group [49.1% (281/572)] was significantly lower than in MCDA group [75.5% (83/110)] (χ2=25.698, P<0.05). In DCDA group, women delivered at 36-36+6 weeks, 37-37+6 weeks and 38-38+6 weeks had lower rates of admission to neonatal intensive care unit (NICU), neonatal respiratory distress syndrome (NRDS) and other neonatal diseases than those delivered at <34 weeks, 34-34+6 weeks and 35-35+6 weeks (all P<0.05), while those delivered at 38-38+6 weeks had a higher incidence of pathological jaundice (2/8) than at 36-36+6 weeks and 37-37+6 weeks (3.1% and 1.9%) (χ2=10.133 and 13.510, both P<0.05). In MCDA group, the rate of admission to the NICU decreased gradually from 100.0% (30/30) (<35 weeks) to 3/12 (37-37+6 weeks) (P<0.05). In DCDA group, the odds ratio (OR) and 95% confidence interval(95%CI) of adverse neonatal outcomes in 35-35+6, 36-36+6 and 37-37+6 weeks were 0.237(0.116-0.482), 0.056(0.029-0.108) and 0.054(0.026-0.112), respectively (all P<0.05). In MCDA group, OR (95%CI) of adverse neonatal outcomes in 34-34+6 and 35-35+6 weeks were 38.894 (3.084-490.552)and 18.858 (1.538-231.222), respectively (both P<0.05). (2) With regard to mode of delivery, ten cases of DCDA and two cases of MCDA had vaginal deliveries. In DCDA group who gave birth at less than 34 weeks, the incidence of neonatal pathological jaundice in vaginal delivery group (8/14) was higher than that in cesarean delivery group [22.7% (15/66)] (χ2=5.104, P=0.024). Conclusions The optimal time of delivery for uncomplicated twins is 36-37+6 weeks. The appropriate mode of delivery should be determined by the status of both the mother and the twins. Key words: Pregnancy, twin; Pregnancy complications; Parturition; Delivery, obstetric; Pregnancy outcome