One-step vs. two-step gestational diabetes mellitus screening and pregnancy outcomes: an updated systematic review and meta-analysis.

Objective We performed a systematic review and meta-analysis comparing maternal and neonatal outcomes of patients screened with one-step or two-step screening methods for GDM. Data sources Pubmed, Scopus, Cochrane, ClinicalTrials.gov, and LILACS were searched from inception up to September 2022. Study Eligibility Criteria Only randomized controlled trials (RCTs) were included. Studies that had overlapping populations were excluded (PROSPERO CRD42022358903). Study Appraisal and Synthesis Methods Risk ratios (RR) were computed with 95% confidence intervals (CI) by two authors. Unpublished data were requested. Large for gestational age (LGA) was the primary outcome. Results The search yielded 394 citations. Seven RCTs met inclusion criteria. A total of 54,650 participants were screened for GDM by either the one-step method (N=27,163) or the two-step method (N=27,487). For LGA, there were no significant differences found between groups (RR 0.99; 95% CI 0.93-1.05; I2=0%). Newborns of patients in one-step testing had higher rates of neonatal hypoglycemia (RR 1.24; 95% CI 1.14-1.34; I2 =0%) and NICU admissions (RR 1.13; 95% CI 1.04-1.21; I2=0%). Patients in the one-step group were more likely to be diagnosed with GDM (RR 1.73; 95% CI 1.44-2.09; I2=80%). In addition, among trials that tested all patients prior to and excluded patients with pregestational diabetes, newborns were more likely to have macrosomia (RR 1.27; 95% CI 1.21- 1.34; I2=0%). Overall risk of bias assessment was of low concern. Conclusions LGA did not differ between patients screened by one-step method and those by two-step method. However, patients randomized to one-step method had higher rates of neonatal hypoglycemia and NICU admission as well as maternal GDM diagnosis than the two-step method.