Hyperglycemia or gestational diabetes is associated with an increased risk of adverse perinatal outcomes, including cesarean section and macrosomia. This study aims to examine the association between maternal glucose concentrations and adverse perinatal outcomes in women without gestational or existing diabetes.

This was a systematic review and meta-analysis of 25 prospective cohort studies and control arms of randomized trials, including up to 207,172 pregnant women with oral glucose tolerance (OGTT) or challenge (OGCT) test results. Data on the induction of labor, cesarean and instrumental delivery, pre-eclampsia, macrosomia, and neonatal hypoglycemia were extracted. The primary outcome of the study was the incidence of adverse perinatal outcomes.

The meta-analysis of studies suggested a positive linear association between the cesarian section, large for gestational age, induction of labor, macrosomia, and shoulder dystocia for across the distribution of glucose concentrations. However, no clear evidence of a threshold effect was observed. Besides, stronger associations were discovered for fasting concentration when compared with post-load concentration. Most studies had a low risk of bias, and the heterogeneity was low between studies included in this analysis.

Ther research concluded that there was a positive association between maternal glucose levels and the risk of adverse perinatal outcomes. However, there was a lack of a clear threshold.

Ref: https://www.bmj.com/content/354/bmj.i4694