Comparing Two Gestational Diabetes Screening Methods: A Pragmatic Outpatient RCT

Two recent randomized placebo-controlled trials show that gestational diabetes (GDM) treatment (vs. none) improves maternal and perinatal outcomes, based on diagnosis with a 2- step screening strategy. Also, a large multi-center prospective cohort study showed a linear relationship with glucose and maternal and perinatal outcomes, based on screening with a single 75g oral glucose tolerance test (OGTT). Based on this large cohort's findings, the American Diabetes Association recommended that clinical practice adopt the 1-step 75g screening approach for diagnosing GDM. The American College of Obstetrics & Gynecology took the opposite stance, recommending the traditional 2-step screening: because it alone has RCT outcome evidence. What is urgently needed to best inform clinical practice and health policy is not an additional GDM treatment vs. control trial, but a pragmatic randomized controlled trial (RCT) testing the 2 recommended clinical strategies. To pragmatically address this critical research gap, we propose to randomize an estimated 17,626 diverse women to GDM screening (2-step vs. 75g OGTT) as part of their clinical care in the Kaiser Permanente Northwest (KPNW) and Hawaii (KPH) regional health plans. The investigators will use the plans' electronic medical record (EMR) system at the time of GDM screening to randomize the women. Both KPNW and KPH regions universally screen for GDM at 24-28 weeks gestation, as part of clinical care. By randomizing GDM screening in the context of clinical care, the investigators will: Compare GDM prevalences (Aim 1) and differences in maternal and perinatal outcomes between screening strategies (Aim 2). Determine the concordance of the 75g OGTT with GDM diagnosed by 2-step, among a recruited sub-sample of 1,000 pregnant women at KPNW and KPH (Aim 3). The results of this pragmatic RCT are expected to help resolve the current public policy debate on the potential benefits and risks of each strategy in clinical obstetric practice.