The Association between the Intertwin Interval and Adverse Neonatal Outcomes.

Objective  Previous data examining the association between the interval between the delivery of the first and second twin (intertwin interval) and adverse neonatal outcomes are conflicting. We sought to evaluate whether intertwin interval is associated with adverse neonatal outcomes for the second twin in a contemporary U. S. cohort. Methods  This is a cohort study of women who delivered twins at or after 32 weeks gestation between 2006 and 2014 and whose first twin was delivered vaginally vertex. The intertwin interval was dichotomized as < 10 minutes or ≥ 10 minutes. Adverse outcomes included arterial cord pH ≤ 7.1, admission to the neonatal intensive care unit, respiratory distress, intraventricular hemorrhage, and death. Results  Of the 171 subjects, 61 (35.7%) had an intertwin interval of ≥ 10 minutes. There were no differences in maternal characteristics. Intertwin interval of ≥ 10 minutes was associated with an increased frequency of arterial pH ≤ 7.1 (22.0 vs. 8.2%, p  = 0.03), which persisted after adjusting for confounders (adjusted odds ratio, 2.94; 95% confidence interval, 1.04-8.33). Other adverse outcomes did not differ. Conclusion  Intertwin interval of ≥ 10 minutes was associated with increased frequency of arterial pH ≤ 7.1 in the second twin, but no other adverse neonatal outcomes.