Previous poor pregnancy outcomes linked to preterm birth

preterm baby
Preterm birth, where babies are born before 37 weeks, affects 10% of babies in the United States. It’s important to try to identify people at risk for preterm birth, and most efforts have been targeted at women who’ve had a previous preterm birth.

New research adds an important dimension to the conversation by studying the risk of preterm birth among women with a previous poor pregnancy outcome. Researchers studied women in California in their second pregnancy who’d had a previous full term birth, but had a problem with their first birth. They looked at the type of adverse pregnancy outcome they’d experienced as well as timing of the preterm birth (before 32 weeks or between 32 and 36).

They found that women had an increased risk of preterm birth if they previously had an infant small for their gestational age, placental abruption (where the placenta detaches from the uterus) or had an infant die within the first 28 days of their life. The risk of giving birth before 32 weeks was higher for women who had an infant small for their gestational age. Women with a previous neonatal death were three times as likely to have a subsequent preterm birth. Overall this group of women had low rates of preterm birth because they hadn’t had a previous preterm birth.

This research offers new insight into risk of preterm birth and other complications. Identifying a biological link between these adverse pregnancy outcomes and preterm birth in a subsequent pregnancy may suggest effective interventions to reduce preterm birth and prevent medical problems for mothers and infants.