Periconceptional use of the following agent leads to reduced incidence of neural tube defects

Women should begin taking folic acid supplements before becoming pregnant and continue taking the supplements of at least 0.4 mg/day throughout the first trimester to reduce the risk of neural tube defects. It has been shown to reduce the occurrence and recurrence of neural tube defects . For low-risk women, folic acid supplementation of 400 micrograms per day currently is recommended For women at high risk of NTDs or who have had a previous pregnancy with an NTD, folic acid supplementation of 4 mg per day is recommended.