Association of low birthweight and premature birth with hypertensive disorders in pregnancy: a systematic review and meta-analysis

Background: Growing evidence suggests that women born preterm or small have an increased risk of experiencing hypertensive disorders during pregnancy; however, a quantitative summary of the evidence on this issue is unavailable. Objective: We aimed to systematically review the literature to describe the association between being born preterm, low birthweight (LBW), or small for gestational age (SGA), and future gestational hypertension, preeclampsia, or eclampsia. Methods: We searched the MEDLINE, Embase, CINAHL, ClinicalTrials.gov, and ICTRP databases. We included all cohort and case–control studies examining the association between LBW, preterm birth, or SGA and hypertensive disorders in pregnancy. We pooled the odds ratios and 95% confidence intervals using the DerSimonian and Laird random-effects model. We assessed the certainty of evidence for each outcome using the Grading of Recommendations, Assessment, Development, and Evaluation criteria. Results: Eleven studies were identified, totalling 752 316 participants. Being born preterm, LBW, or SGA was associated with gestational hypertension [pooled odds ratio (OR), 1.31; 95% confidence interval (CI) 1.15–1.50; moderate certainty of evidence] and preeclampsia (pooled OR, 1.35; 95% CI 1.23–1.48; moderate certainty of evidence). No study measured eclampsia as an outcome. Conclusion: Women born preterm, LBW, or SGA have an increased risk of gestational hypertension and preeclampsia. The course of the mother's own birth might be used to identify women at risk of gestational hypertension and preeclampsia.