How effective is the lactational amenorrhea method?

The lactational amenorrhea method (LAM) can be highly effective in preventing pregnancy, with a success rate of about 98% when used correctly. It relies on exclusive breastfeeding, which suppresses ovulation, and is most effective during the first six months postpartum when menstruation has not yet resumed. For LAM to be effective, the mother must breastfeed frequently (about every 4 hours during the day and every 6 hours at night) and avoid supplementing with other foods or liquids. Once any of these conditions change, the effectiveness decreases significantly.