When are pregnant women typically screened for gestational diabetes mellitus?

Screening for gestational diabetes mellitus (GDM) typically occurs between 24 and 28 weeks of gestation because this timeframe aligns with the period when insulin resistance commonly develops due to hormonal changes associated with pregnancy. During this phase, the body may have difficulty utilizing insulin effectively, raising the risk of glucose intolerance and subsequent GDM.

Screening at this stage allows for earlier identification and management of potential GDM, which is crucial for the health of both the mother and the developing fetus. Detecting and controlling blood sugar levels can help prevent complications such as large birth weight, preterm birth, and increased risk of cesarean delivery.

Although some women may be assessed at their first prenatal visit, it is not standard practice for all. The other choices, such as screening at 12 weeks or after delivery, would miss the critical period for intervention during pregnancy itself, where timely management can significantly impact outcomes.