One-hour vs Two-hour Postprandial Glucose Targets and Fetomaternal Outcomes in Gestational Diabetes Mellitus: A Systematic Review and Meta-Analysis.

Abstract

Objective: The optimal time and target for postprandial glucose (PPG) measurement in gestational diabetes mellitus (GDM) remain unclear. This systematic review and meta-analysis evaluated whether targeting 1-hour PPG (1 hPG) vs 2-hour PPG (2 hPG) altered fetomaternal outcomes in GDM.

Methods: Studies that compared pregnancy outcomes in women undergoing 1 hPG vs 2 hPG monitoring in GDM were identified through comprehensive search of electronic databases. Primary outcomes analyzed were large-for-gestational age (LGA) and macrosomia. Secondary outcomes included low birthweight (LBW), neonatal intensive-care unit admission, neonatal hypoglycemia, cesarean section (CS), pre-eclampsia, gestational age at delivery, and preterm delivery.

Results: Six articles that compared 1 hPG<140 mg/dL (7.8 mmol/L) vs 2 hPG <120 mg/dL (7.2 mmol/L) were analyzed. Additionally, 3 articles that assessed 1 hPG<120 mg/dL vs1 hPG<140 mg/dL were also examined. Targeting 1 hPG<140 mg/dL vs 2 hPG<120 mg/dL significantly lowered the risk of LGA [odds ratio (OR) 0.54; 95% confidence interval (CI): 0.32-0.93; P = .03] but not macrosomia [OR 0.45; 95%CI:0.19-1.06; P = .07]. There was no difference in other parameters such as birthweight [mean difference -61.77g; 95%CI:-152.16-28.62; P = .018], LBW [OR 0.90; 95%CI:0.30-2.68;P = .85], neonatal hypoglycemia [OR 0.60; 95%CI:0.28-1.26; P = .18], gestational age at delivery [mean difference 0.20 weeks; 95%CI:-0.29-0.68; P = .43], CS [OR 0.99; 95%CI:0.46-2.12;P = .97], pre-eclampsia [OR 0.66;95% CI:.22-1.96; P = .46], or need for insulin therapy [OR 1.39; 95%CI:.79-2.43; P = .25]. More intensive 1 hPG target <120 mg/dL vs <140 mg/dl increased the risk of preterm delivery [OR 1.62; 95% CI:1.00-2.62; P = .05], without affecting birthweight, LGA, macrosomia, LBW, and CS.

Conclusion: Our findings suggest that targeting 1 hPG <140 mg/dL vs 2 hPG<120 mg/dL lowers the risk of LGA, but does not affect other parameters. A stricter target of 1 hPG<120 mg/dL can increase the risk of preterm delivery. Further studies to corroborate these findings are necessary.