Maternal age and the risk of gestational diabetes mellitus: A systematic review and meta-analysis of over 120 million participants

Aims: The objective of the present analysis was to evaluate and quantify the risk for gestational diabetes mellitus (GDM) according to maternal age.

Methods: Three electronic databases were searched for publications from inception to July 2018. Odds ratio (OR) and 95% confidence interval (95% CI) were calculated. A dose-response analsis was performed using generalised least squares regression. Subgroup and meta-regression analyses were conducted to explore the source of identified heterogeneity among studies.

Results: Twenty-four studies were included in the present meta-analysis. The ORs and 95% CIs for women aged <20 years vs 25-29 years, 30-34 years, 35-39 years and ≥40 years were 0.60 (95% CI = 0.50-0.72), 1.69 (95% CI = 1.49-1.93), 2.73 (95% CI = 2.28-3.27), 3.54 (95% CI = 2.88-4.34) and 4.86 (95% CI = 3.78-6.24), respectively. Dose-response analysis showed that GDM risk exhibited a linear relationship with maternal age (P_trend < 0.001). For each one-year increase in maternal age from 18 years, GDM risk for the overall population, Asian, and Europid increased by 7.90%, 12.74%, and 6.52%, respectively. Subgroup analyses indicated that from the age of 25, Asian women had a significantly higher risk of developing GDM than Europid women (all P_interactions < 0.001).

Conclusions: This meta-analysis demonstrates that the risk of GDM increases linearly with successive age-groups.