Clinical Edge

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Short Interpregnancy Intervals & Pregnancy Outcomes

JAMA Intern Med; ePub 2018 Oct 29; Schummers, et al

Short interpregnancy intervals are associated with increased risks for adverse pregnancy outcomes for women of all ages, a new study found. The population-based cohort study of 148,544 pregnancies evaluated women with ≥2 singleton pregnancies from 2004 to 2014 with the first (index) pregnancy resulting in a live birth. Researchers found:

  • Maternal mortality or severe morbidity risks were increased at short interpregnancy intervals among women aged ≥35 years but not for women aged 20‒34 years.
  • Conversely, increased risks of adverse fetal and infant outcomes and spontaneous preterm delivery were more pronounced for women aged 20‒34 years than for women aged ≥35 years.
  • Modest increases in risks of small-for-gestational age and indicated preterm delivery at short intervals did not vary meaningfully by maternal age.


Schummers L, Hutcheon JA, Hernandez-Diaz S, et al. Association of short interpregnancy interval with pregnancy outcomes according to maternal age. [Published online ahead of print October 29, 2018]. JAMA Intern Med. doi:10.1001/jamainternmed.2018.4696.