Which maternal condition can lead to an increased risk of fetal macrosomia?

Gestational diabetes is a significant maternal condition associated with an increased risk of fetal macrosomia, which is defined as a birth weight greater than 4,000 grams (approximately 8 pounds, 13 ounces). When a mother has gestational diabetes, her body experiences elevated blood glucose levels due to insulin resistance. This increase in maternal blood sugar can lead to higher amounts of glucose crossing the placenta to the fetus, prompting the fetal pancreas to produce more insulin. Elevated insulin levels in the fetus can promote excessive growth and fat accumulation, resulting in macrosomia.

In contrast, while other conditions such as high blood pressure, thyroid disorders, and anemia can affect pregnancy and fetal outcomes, they do not have the same direct correlation with increased fetal growth as gestational diabetes. High blood pressure may lead to complications like preeclampsia and placental insufficiency, but it does not independently cause fetal macrosomia. Similarly, thyroid disorders can affect metabolic processes and fetal development but aren’t directly linked to the excessive growth associated with macrosomia. Anemia, while it can lead to various pregnancy challenges, primarily impacts oxygen delivery rather than contributing to increased fetal size.

Thus, gestational diabetes is the key condition that has a well-established link to macrosomia due to