Use of folic acid to prevent congenital malformation should be best initiated:

Ans. is d, i.e. Before conceptionRef. Dutta Obs. 9/e, p 383; COGDT 10/e, p 197"Folic acid has been shown to effectively reduce the risk of neural tube defects (NTD's). A daily 4 mg dose is recommended for patients who have had a previous pregnancy affected by neural tube defects. It should be started atleast 1 month (ideally 3 months) prior to pregnancy and continued through the first 6-12 weeks of pregnancy." Ref. COGDT 10/e, p 197Remember: Folic acid is used to reduce the risk of neural tube defect.More than half of NTDs could be prevented with daily intake of 400 mg of folic acid throughout the periconceptional period.Thus dose of folic acid which is given to all pregnant females = 0.4 mg, i.e. 400 mcg (also called as prophylactic dose).A woman with a prior pregnancy complicated by a neural tube defect can reduce the 23% recurrence risk by more than 70% if she takes 4 mg of folic acid for the month before conception and for the first trimester of pregnancy. This called a therapeutic dose of folic acid.Therapeutic dose of folic acid (to be given in females with previous history of baby with NTD)--4 mg.Duration: It should be started 1 month before conception and continued till first 6-12 weeks of pregnancy.Dose of folic acid given to pregnant women with megaloblastic anemia = 1 mg day.