Maternal hyperglycemia during pregnancy is associated with delayed fetal lung maturity due to decreased surfactant production.

• A. False
• B. True
• C. Not established
• D. Only in type 1

Answer: (B)

Hyperglycemia in the mother raises fetal glucose, which drives fetal insulin production. Elevated fetal insulin dampens signals that promote lung maturation, notably inhibiting surfactant synthesis by type II pneumocytes. Surfactant lowers surface tension in the immature lung, and without enough of it, the newborn is at higher risk for respiratory distress syndrome. This effect occurs with maternal diabetes in general, not just type 1, especially if glycemic control is poor. Therefore, maternal hyperglycemia is associated with delayed fetal lung maturity due to decreased surfactant production.