Prospective risk of stillbirth in multiple-gestation pregnancies: a population-based analysis.

Abstract

To evaluate the prospective risk of stillbirth in multiple gestations. We conducted a retrospective analysis of birth notifications and infant mortality records relating to all multiple gestations to residents in a predefined health district. The incidence of live births and stillbirths was used to calculate the prospective risk of stillbirth at each week of gestation. The risk of stillbirth in multiple gestations increased from 1:3333 at 28 weeks' gestation to 1:69 at 39 or more weeks' gestation. The stillbirth risk in multiple gestations at 39 weeks surpassed that of postterm singleton pregnancies (1:526). Multiple gestations at 37-38 weeks have a risk of stillbirth equivalent to that of postterm singleton pregnancy. Because multiple gestations rarely proceed beyond 39 weeks, and because stillbirth risk increases several-fold beyond this stage, elective delivery might be justified at this gestational age.