Twin pregnancy outcomes after increasing rate of vaginal twin delivery: retrospective cohort study in a Hong Kong regional obstetric unit.

Objective: To determine any change in adverse neonatal/maternal outcomes after increasing the rate of vaginal twin delivery by comparing vaginal twin delivery and caesarean delivery with our previous cohort study.Methods: In a retrospective cohort study, all twins booked at a Hong Kong regional obstetrics unit were evaluated during a 3-year period from 1 April 2009 to 31 March 2012.Results: Out of the 269 sets of twins who eventually delivered in our unit, 68 (25.3%) of them were delivered vaginally, compared to 15.8% in our previous cohort study (p=0.02). For those who were suitable for vaginal delivery, significantly more women attempted vaginal delivery: 93/133 (69.9%) versus 47/100 (47%) (p=0.0005). The success rate for vaginal delivery and rate of requiring caesarean delivery for the 2nd twin were similar between these two periods. There were significantly more 2nd twins with cord blood pH<7.2 when both twins were delivered by vaginal delivery. Otherwise, there was no significant difference between other neonatal/maternal morbidities.Conclusion: With proper counseling, significantly more women who were suitable for vaginal twin delivery would opt to do so. There was no significant increase in neonatal/maternal morbidities despite the increased rate of vaginal twin delivery.