# Opportunity Screening for Early Detection of Gestational Diabetes: Results from the MERGD Study

## TL;DR

This study identifies a high-risk group of pregnant women who may benefit from early detection of gestational diabetes based on modified diagnostic criteria.

## Contribution

A new risk group (RG2) is identified with perinatal outcomes similar to diagnosed gestational diabetes.

## Key findings

- RG2 showed higher odds of antepartum complications and adverse outcomes compared to RG0.
- RG2 was significantly associated with pregnancy-induced hypertension and other complications.
- The two-step approach identified 4.6% of women as GD, with 7.2% in the high-risk RG2 group.

## Abstract

Background: The definitions and approaches used to diagnose gestational diabetes (GD) are varied. The two-step approach recommended by the American College of Obstetricians and Gynecologists (ACOG) combines the sensitivity of a glucose challenge test (GCT) with the specificity of a 3-hour oral glucose tolerance test (OGTT). We investigated if minor modification of the two-step procedure can provide improved detection of GD by identifying a risk group of pregnant women with high risk of GD. Methods: We conducted a prospective cohort study of pregnant women enrolled early during pregnancy and followed till delivery. All participants underwent the ACOG-recommended two-step procedure for GD diagnosis. Based on GCT and OGTT results, the participants were divided into four risk groups (RGs): GCT-negative (RG0), GCT-positive but OGTT normal (RG1), single abnormal value on OGTT or raised HbA1c (RG2) and diagnosed GD (RG3). Baseline evaluation included dietary history (24 hour recall) and physical activity. A series of multivariable logistic regression analyses were conducted to estimate the odds of maternal and fetal outcomes. Results: A total of 1041 pregnant women were included in the study, of whom 16 (1.6%) were diagnosed as GD. Our two-step approach identified 48 (4.6%) women as GD, while RG2, RG1 and RG0 comprised 75 (7.2%), 218 (20.9%) and 700 (67.2%), respectively. Compared to RG0, RG2 showed a higher likelihood of antepartum complications [odds ratio and 95% confidence interval 2.38 (1.16–4.15)], any adverse outcome without [2.04 (1.17–3.55)] or with cesarean section [2.09 (1.21–3.61)] and primary cesarean section [1.68 (1.01–2.81)] after adjustment for potential confounders. RG2 was also significantly associated with pregnancy-induced hypertension, meconium-stained amniotic fluid and premature rupture of membranes. Conclusions: In the study participants, we identified a subgroup (RG2) at high risk of GD with perinatal outcomes showing profile consistent with that of GD.