Correlation between first- and early third-trimester glucose screening test results.

Area of Science:

• Obstetrics and Gynecology
• Endocrinology
• Maternal-Fetal Medicine

Background:

• Gestational diabetes mellitus (GDM) is a common pregnancy complication.
• Early identification of GDM risk is crucial for timely intervention and improved maternal-fetal outcomes.
• Standard screening protocols typically involve glucose testing in the second or third trimester.

Purpose of the Study:

• To evaluate the predictive value of first-trimester oral glucose screening tests for third-trimester glucose screening results and GDM diagnosis.
• To determine if first-trimester screening can identify pregnancies at low risk, potentially obviating the need for later screening.

Main Methods:

• One hundred twenty-four pregnant individuals underwent paired first- and early third-trimester 1-hour oral glucose screening tests.
• Correlation analysis was performed between first-trimester and third-trimester glucose screening values.
• Incidence of GDM was compared between groups based on first-trimester glucose levels.

Main Results:

• First-trimester glucose screening values significantly correlated with third-trimester results across diverse demographic groups.
• First-trimester values ≤110 mg/dL were rarely associated with elevated third-trimester results or abnormal glucose tolerance tests (GTT).
• All nine (7.3%) GDM diagnoses occurred in individuals with first-trimester screening values >110 mg/dL, a highly significant difference (P < .0001).

Conclusions:

• First-trimester oral glucose screening demonstrates significant predictive value for GDM risk.
• Pregnant individuals with first-trimester screening values ≤110 mg/dL may not require repeat third-trimester screening.
• Elevated first-trimester screening values (≥135 mg/dL) indicate a high risk for GDM and warrant a direct third-trimester 3-hour GTT.