One tablet of IFA is to be taken daily starting from the fourth month of pregnancy. If the mother is anaemic, she will be advised to take two IFA tablets daily, one tablet in the morning and one in the evening.

Taking one IFA tablet a day keeps anaemia away in mothers and ensures delivery of a healthy baby

Ref : http://nhm.gov.in/images/pdf/programmes/maternal-health/guidelines/my_safe_motherhood_booklet_english.pdf