What is the side effect of folic acid on baby?

Folic acid: Folic acid deficiency can cause neural tube defects in the fetus, and Folic Acid supplementation can prevent them. Folic acid supplementation around the time of coneception reduces the incidence of neural tube defects by 50 to 70 percent.

To help prevent: Neural tube defects like spina bifida & other congenital anomalies, women of child-bearing age must take 400-800 micrograms (.4-.8 mg) of folate (folic acid) daily for at least 3 mos. Before conception. The neural tube that turns into the brain & spinal cord starts forming at 3 weeks after conceiving. Tie a bottle of folate (folic acid) onto every wedding present you give, even if the couple is not planning a pregnancy.