The intergenerational association of preterm birth: A systematic review and meta-analysis.

Background: Around half of preterm births lack identifiable causes, indicating the need for further investigation to understand preterm birth risk factors. Existing studies on the intergenerational association of preterm birth showed inconsistency in effect size and direction.

Objective: This systematic review and meta-analysis aimed to review existing studies and provide comprehensive evidence on the intergenerational association of preterm births.

Search strategy: We searched MEDLINE, Embase and Maternity and Infant Care databases, from the inception of each database to 04 April 2024.

Selection criteria: Eligibility criteria included studies that reported on women who had given birth and had recorded information about a family history of preterm birth in one or both of the child's biological parents.

Data collection and analysis: Data were extracted by two independent reviewers. A random-effects model was used to compute pooled estimates using odds ratios.

Main results: Sixteen eligible studies with a total of 2 271 612 mothers were included. The findings indicated a 1.44 (OR = 1.44, 95% CI: 1.34, 1.54) fold increase in odds of giving preterm births among women who were born preterm. Additionally, having a sibling born preterm (OR = 1.53, 95% CI: 1.24, 1.87) and having a partner born preterm (OR = 1.12, 95% CI: 1.01, 1.25) were associated with increased likelihood of giving preterm births among women.

Conclusion: The study revealed that women with a family history of preterm birth face an increased risk of giving preterm births. Screening pregnant women for a family history of preterm birth is essential, with those having a positive family history requiring closer follow-up.