Is gestational diabetes mellitus an independent risk factor for macrosomia: a meta-analysis?

The aim of our meta-analysis was to explore whether gestational diabetes mellitus (GDM) is an independent risk factor for macrosomia or not. Three databases were systematically reviewed and reference lists of relevant articles were checked. Meta-analysis of published epidemiological studies (cohort and case-control studies) comparing whether GDM was associated with macrosomia. Calculations of pooled estimates were conducted in random-effect models. Heterogeneity was tested by using Chi square test and I (2) statistics. Publication bias was estimated from Egger's test (linear regression method) and Begg's test (rank correlation method). Twelve studies met the inclusion criteria, including five cohort studies and seven case-control studies. The meta-analysis showed that GDM was associated with macrosomia independent of other risk factors. The adjusted odds ratio was 1.71, 95 % CI (1.52, 1.94) in random-effect model, stratified analyses showed no differences regarding different study design, quality grade, definition of macrosomia, location of study and number of confounding factors adjusted for. There was no indication of a publication bias either from the result of Egger's test or Begg's test. Our findings indicate that GDM should be considered as an independent risk factor for newborn macrosomia. To adequately evaluate the clinical evolution of GDM need to be carefully assessed and monitored.