For a study, researchers sought to compare one-step testing for gestational diabetes mellitus (GDM) to two-step testing to determine short-term maternal and newborn outcomes.

Before September 2021, a thorough analysis of randomized controlled trials (RCTs) and observational studies contrasting one-step and two-step GDM testing approaches was carried out. The main result was the rate of newborns who were large-for-gestational-age (LGA). Secondary endpoints were predetermined, clinically significant outcomes for GDM. The first two writers examined, chose, and assessed titles, abstracts, and papers. The analysis included 4 RCTs (24,966 individuals) and 13 observational studies (710,677 people). 

Random-effects models were used to determine pooled relative risks (RRs), which were then visually shown using forest plots and given 95% CIs. Higgins I2 and Cochran Q tests were used to assess study heterogeneity. The Downs and Black checklist was used to assess the standard of research that satisfied the inclusion criteria. Utilizing funnel plot asymmetry and Harbord’s test, publication bias was evaluated. According to the testing strategy, there was no difference in the rate of LGA neonates among RCTs (pooled RR 0.95; 95% CI 0.88-1.04), but patients who underwent one-step testing were more likely to be diagnosed with GDM (pooled RR 2.13; 95% CI 1.61-2.82) and treated with diabetes medications (pooled RR 2.24; 95% CI 1.21-4.15). In addition, one-step testing was linked to increased rates of newborn hypoglycemia (pooled RR 1.23; 95% CI 1.13-1.34) and neonatal intensive care unit (NICU) admission (pooled RR 1.12; 95% CI 1.00-1.26). One-step testing was linked to decreased rates of LGA neonates (pooled RR 0.97; 95% CI 0.95-0.98) in analyses of high-quality RCTs and observational studies, but increased rates of GDM diagnosis, treatment, NICU hospitalization, and newborn hypoglycemia.

There was no change in the rate of LGA neonates compared with two-step testing among RCTs, despite a considerable rise in GDM diagnosis and treatment with one-step testing.