服用葉酸補充劑至少一年可以減少早產(20 to 28 weeks)的機率達70%。對於28 to 32 weeks早產則是50%。早產兒容易有腦性痲痺、智障、慢性肺病等問題。

葉酸不足容易造成神經管缺陷。

 Bukowski R, et al. Preconceptional Folate Prevents Preterm Delivery. Presented at the 28th Annual Society for Maternal-Fetal Medicine (SMFM) meeting, Dallas, Texas,  January 28, 2008 - February 2, 2008.