They are of maximum benefit 1 month before and the first three months of pregnancy. Hiwever as othe food like vegetables and fruits also contain small amiunts of folic acid thus majority of the babies do well even in the absence of supplements.
Next Steps
The ill effects of not taking the folic acid although serious affect only a small number of babies and are almost always visible on sonography (ultrasound scan) at 18 weeks. Thus if your scan is normal rest reassured.
Health Tips
However tell all your friends and family also in your next pregnancy to take folic acid cid for at least 1 month before and the first three months of pregnancy.