Glucose monitoring in the management of diabetes in pregnancy: A systematic review and meta‐analysis

Abstract Background Diabetes in pregnancy (DIP: gestational, type 1 [T1D], and type 2 diabetes [T2D]) is increasing in global prevalence and was recently declared a public health priority by the World Health Organization (WHO). Aim This systematic review and meta‐analysis evaluated different glucose monitoring management for DIP, including routine care at antenatal visits, self‐monitoring of blood glucose (SMBG), and continuous glucose monitoring (CGM) to inform new WHO recommendations on care for pregnant women with DIP. Methods We searched Medline, Embase, CENTRAL, and LILACs from database inception to October 2024 for randomized controlled trials (RCTs), comparing SMBG with routine care at antenatal visits or CGM with SMBG. Data were extracted on maternal glycemia (HbA1c, SMBG fasting, 1‐h postprandial glucose, CGM metrics [mean sensor glucose, pregnancy time‐in‐range, time‐above‐range, and time‐below‐range]) and perinatal outcomes (gestational weight gain, hypertensive disorders of pregnancy, preeclampsia, large‐for‐gestational age [LGA], macrosomia, small‐for‐gestational age, neonatal hypoglycemia, and neonatal intensive care unit [NICU] admissions). Measures of effect were summarized as mean differences (MDs) or risk ratios (RRs) with 95% confidence intervals (95% CI) for gestational diabetes, T1D and T2D. The GRADE framework was used to assess the certainty of effect estimates. Results In gestational diabetes, SMBG compared to routine care at antenatal visits reduced LGA ( n = 2719; RR, 0.60 [0.50, 0.72]) and macrosomia ( n = 2661; RR, 0.50 [0.39, 0.64]) (high‐certainty evidence) and probably reduced gestational weight gain ( n = 2616; MD, −1.58 kg [−2.22, −0.94]) (moderate‐certainty evidence). CGM compared to SMBG probably reduced gestational weight gain ( n = 221; MD, −0.61 kg [−0.92, −0.31]) and preeclampsia ( n = 277; RR, 0.34 [0.12, 0.91]) (moderate‐certainty evidence). In T1D, CGM compared to SMBG probably increased pregnancy time‐in‐range ( n = 154; MD, 7.00% [2.57, 11.43]) and probably reduced neonatal hypoglycemia ( n = 200; RR, 0.54 [0.31, 0.94]) and NICU admissions ( n = 200; RR, 0.63 [0.42, 0.93]) (moderate‐certainty evidence). There was insufficient RCT evidence to compare approaches to glucose monitoring in T2D. Conclusions SMBG improves important perinatal outcomes for pregnant women with gestational diabetes, T1D and T2D. CGM probably provides additional benefit for maternal glycemia in T1D, and for some perinatal outcomes in T1D and gestational diabetes. More evidence is needed to determine the potential benefits of CGM for women with T2D in pregnancy.