Interpregnancy interval and perinatal outcomes after a perinatal loss

Abstract

<h3>Objectives</h3> There is little evidence available to support pregnancy spacing decisions after a perinatal loss. The objective of this study was to examine whether short interpregnancy intervals after a perinatal loss are associated with increased risks of adverse outcomes in the subsequent pregnancy. <h3>Methods</h3> We analyzed all pregnancies from 2004–2014 to women with ≥2 singleton pregnancies, with the first resulting in a stillbirth or late termination at (≥20 weeks) or a neonatal death. According to interpregnancy interval, we examined risks in the subsequent pregnancy of small-for-gestational-age, adverse fetal-infant composite (stillbirth, neonatal death, <3rd birth weight percentile, delivery <28 weeks); and spontaneous and indicated preterm delivery. We used log binomial regression to estimate risk ratios (aRR) comparing short (<6, 6–11, 12–17-month) intervals with a reference 18–23-month group adjusted for maternal age, smoking, parity, low neighborhood income, inadequate prenatal care, and index pregnancy outcomes, all measured at or before the delivery of the index pregnancy. <h3>Results</h3> Of 148,544 interpregnancy intervals in the study period, the study sample included 2,041 pregnancies, 1,626 following a stillbirth/late termination and 405 following a neonatal death. Risks of most outcomes were not increased at short (<6-month) vs. 18–23-month interpregnancy intervals: adverse fetal-neonatal composite, aRR 0.9 [95% CI 0.4–1.8]; small-for-gestational-age, aRR 0.6 [0.3–1.], and indicated preterm delivery, aRR 0.6 [CI 0.4–1.0]. However, spontaneous preterm delivery risks were increased, aRR 2.1 [CI 1.0–4.4]. <h3>Conclusions</h3> After a perinatal loss, short interpregnancy interval was associated with increased risk of spontaneous preterm delivery, but not other adverse pregnancy outcomes.