Relationship Between Early-Pregnancy Glycemia and Adverse Outcomes: Findings From the TOBOGM Study

Area of Science:

• Obstetrics and Gynecology
• Endocrinology
• Perinatal Medicine

Background:

• Gestational diabetes mellitus (GDM) diagnosis typically occurs later in pregnancy.
• Early identification of hyperglycemia risk factors and their association with pregnancy outcomes is crucial.
• The Treatment of Booking Gestational Diabetes Mellitus (TOBOGM) cohort provides data for evaluating early pregnancy metabolic markers.

Purpose of the Study:

• To assess the association between early-pregnancy oral glucose tolerance test (OGTT) glucose levels and pregnancy complications.
• To establish prognostic OGTT thresholds for identifying high-risk pregnancies.
• To inform clinical management strategies for GDM and related conditions.

Main Methods:

• Recruitment of individuals with hyperglycemia risk factors into an international, multicenter GDM treatment trial.
• Performance of a 2-hour, 75-g OGTT at less than 20 weeks' gestation.
• Analysis of early OGTT glucose concentrations, both continuously and categorized (normal, low band, high band).

Main Results:

• Continuous positive associations were found between fasting, 1-hour, and 2-hour OGTT glucose levels and later GDM diagnosis.
• Elevated 1-hour and 2-hour glucose levels correlated with increased risk of a composite perinatal adverse outcome and large-for-gestational-age offspring.
• High 1-hour OGTT glucose (≥10.6 mmol/L) was the only category to significantly predict the composite perinatal outcome.

Conclusions:

• Early-pregnancy OGTT glucose levels demonstrate a continuous positive association with adverse pregnancy outcomes.
• In high-risk pregnancies, a high 1-hour OGTT glucose level is a significant predictor of major perinatal complications.
• These findings support the utility of early OGTT screening for risk stratification in pregnancy.