Gestational diabetes mellitus in women born small or preterm: Systematic review and meta-analysis

There is some evidence that women born preterm or with low birth weight (LBW) have an increased future risk of gestational diabetes mellitus (GDM) during pregnancy; however, a quantitative summary of evidence is lacking. In this systematic review and meta-analysis, we examined the published data to investigate whether being born preterm, with LBW or small for gestational age (SGA) are associated with GDM risk.We searched the MEDLINE, Embase, and CINAHL databases and study registries, including ClinicalTrials.gov and ICTRP, from launch until 29 October 2020. Observational studies examining the association between birth weight or gestational age and GDM were eligible. We pooled the odds ratios and 95% confidence intervals using the DerSimonian and Laird random-effects model.Eighteen studies were included (N = 827,382). The meta-analysis showed that being born preterm, with LBW or SGA was associated with increased risk of GDM (pooled odds ratio = 1.84; 95% confidence interval: 1.54-2.20; I2 = 78.3%; τ2 = 0.07). Given a GDM prevalence of 2.0, 10, and 20%, the absolute risk differences were 1.6%, 7.0%, and 11.5%, respectively. The certainty of the evidence was low due to serious concerns of risk of bias and publication bias.Women born prematurely, with LBW or SGA status, may be at increased risk for GDM. However, whether this should be considered in clinical decision-making depends on the prevalence of GDM.