What is the role of folic acid during pregnancy?

Folic acid plays a crucial role during pregnancy primarily by helping to prevent neural tube defects. These defects occur when the neural tube, which forms the baby's brain and spinal cord, fails to close properly. Adequate intake of folic acid before conception and in the early stages of pregnancy significantly reduces the risk of these serious birth defects, such as spina bifida and anencephaly. This vital nutrient helps ensure proper cellular formation and growth during the early developmental phases when these structures are forming.

While folic acid may contribute indirectly to overall fetal and maternal health, its most well-documented and critical role in pregnancy specifically pertains to neural tube development and prevention of related defects. Other options regarding fetal brain development, maternal blood pressure regulation, and healthy weight gain may relate to different aspects of prenatal care and nutrition but do not capture the primary preventive function of folic acid as it pertains to neural tube defects.