Clinical Factors Associated With Presentation Change of the Second Twin After Vaginal Delivery of the First Twin.

OBJECTIVE: To identify clinical factors associated with a change from vertex to nonvertex presentation in the second twin after vaginal birth of the first.

METHODS: We assembled a retrospective cohort of women with viable vertex-vertex twin pregnancies who delivered the presenting twin vaginally. Women whose second twin changed from vertex to nonvertex after vaginal birth of the first were classified as experiencing an intrapartum change in presentation. Characteristics associated with intrapartum presentation change in a univariate analysis with a P value ≤.10 were then evaluated in a multivariate logistic regression model.

RESULTS: Four-hundred fifty women met inclusion criteria, of whom 55 (12%) had intrapartum presentation change of the second twin. Women experiencing intrapartum presentation change were more likely to be multiparous (69% compared with 47%, P<.01) and to have had a change in the presentation of the second twin between the most recent antepartum ultrasonogram and the ultrasonogram done on admission to labor and delivery (11% compared with 4%, P=.04). In an adjusted analysis, multiparity and gestational age less than 34 weeks were significantly associated with presentation change (adjusted odds ratio [OR] 2.9, 95% CI 1.5-5.6 and adjusted OR 2.6, 95% CI 1.1-5.9, respectively). Women with intrapartum presentation change were more likely to undergo cesarean delivery for their second twin (44% compared with 7%, P<.01) with an adjusted OR of 10.50 (95% CI 5.20-21.20) compared with those with stable intrapartum presentation. Twenty of the 24 (83%) cesarean deliveries performed in the intrapartum presentation change group were done for issues related to malpresentation.

CONCLUSION: Multiparity and gestational age less than 34 weeks are associated with intrapartum presentation change of the second twin.