Oral or Poster Presentation
Plenary Session - Life Course Effects of Maternal Diabetes
Introduction: Short interpregnancy intervals following livebirth are associated with increased risks of adverse pregnancy outcomes. 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.
Methods: We analyzed all pregnancies in British Columbia 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 (SGA), 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, low neighborhood income, inadequate prenatal care, and index pregnancy outcomes, all measured at or before the index pregnancy delivery. We used logistic regression to create risk curves for each outcome according to interpregnancy interval.
Results: Among 148,544 women with ≥2 singleton pregnancies, the study sample included 2,041 pregnancies, 80% following a stillbirth or late termination (n=1,626) and 20% following a neonatal death (n=405). Incidence of the fetal-neonatal composite was the lowest (5.1%), followed by SGA (6.1%), spontaneous preterm delivery (8.7) and indicated preterm delivery (10.2%). 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]; SGA, 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].
Conclusion: After a perinatal loss, short interpregnancy interval was associated with increased risk of spontaneous preterm delivery, but not other adverse pregnancy outcomes.