Gestational Diabetes Is Associated With Abnormalities in Glucose Excursion in Early Pregnancy

It is unknown if dysglycemia at 24-28 weeks of pregnancy is preceded by glycemic changes earlier in pregnancy. This study therefore examines the association between glucose excursion in the first 20 gestational weeks and the onset of gestational diabetes mellitus (GDM) in the early third trimester.

A cohort study was conducted using data from the electronic medical record of the public health system in Qatar, and women with glycemic assessments done before 20 weeks and again in the early third trimester were assessed. The main outcome of the study was to examine glucose excursion (using Doi's weighted average glucose; dwAG) in early pregnancy to see if it was indicative of GDM diagnosis at the usual time.

At the upper normal cutoff for dwAG (6 mmol/L), the sensitivity and specificity were 71.5% and 54.1%, respectively, and the diagnostic odds ratio was ∼3, meaning that for women beyond this threshold before 20 weeks gestation, they had, on average, a 3-fold increase in odds of developing uGDM compared to women not meeting this threshold.

It is concluded that early pregnancy glucose excursion remains in the normal range in women destined for third trimester GDM but is higher than that in those who do not develop GDM at this time and is a predictor of women at high risk early in pregnancy.