What are the two most common causes of spina bifida?

The correct response identifies insufficient folate and maternal use of valproate as the two most common causes of spina bifida. This condition, a type of neural tube defect, has been strongly associated with maternal nutritional status, particularly folate levels. Adequate folate intake before and during early pregnancy is essential for proper neural tube closure. When there is insufficient folate, the risk of defects like spina bifida significantly increases.

Maternal use of valproate, an anticonvulsant medication, is a notable risk factor as it has been shown to interfere with normal neural tube development. Pregnant women taking valproate are advised to consider alternative medications and to be closely monitored by healthcare professionals due to these associated risks.

While the other options present various risks related to maternal health and fetal development, they are not predominantly linked to spina bifida in the same manner. Genetic factors and infections may contribute to various developmental issues but are not the primary causes of spina bifida. Similarly, lack of prenatal care and maternal substance use can negatively impact pregnancy outcomes but do not specifically highlight the key biological mechanisms associated with spina bifida. Obesity and diabetes are important considerations in maternal health, yet they do not have as strong a