Systematic review and meta-analysis of diagnosing gestational diabetes mellitus with one-step or two-step approaches and associations with adverse pregnancy outcomes.

BACKGROUND: There is an ongoing discussion about the optimal diagnostic strategy for gestational diabetes mellitus (GDM).

OBJECTIVE: To assess the magnitude of the association between GDM diagnosed with the one-step (International Association of Diabetes and Pregnancy Study Groups criteria) or two-step (Carpenter and Coustan criteria) approach and selected adverse pregnancy outcomes.

SEARCH STRATEGY: Five electronic databases were searched up to October 2017 using Medical Subject Headings for each adverse outcome combined with the term "gestational diabetes."

SELECTION CRITERIA: Observational studies assessing the one-step versus the two-step diagnostic approach in GDM.

DATA COLLECTION AND ANALYSIS: Relative risks were extracted and random-effects models were used to estimate pooled relative risks (RRs).

MAIN RESULTS: A total of 41 663 participants from nine studies were included. Gestational diabetes mellitus was significantly associated with pre-eclampsia (RR 1.68 vs RR 1.77), cesarean delivery (RR 1.28 vs RR 1.33), and large for gestational age (RR 1.44 vs RR 1.68) when diagnosed with the one-step versus the two-step approach. A one-step diagnosis also increased the risks of neonatal intensive care unit admission and gestational hypertension, whereas a two-step diagnosis increased the incidence of macrosomia.

CONCLUSIONS: Women with GDM diagnosed with either the one-step or the two-step approach were at increased risk for selected adverse pregnancy outcomes. The associations with the two-step method were slightly stronger.