Breastfeeding and ovulation are often linked because the physical effects of breastfeeding can make the mother infertile for a period of time after birth. Nursing an infant can cause the mother's body to produce prolactins, hormones that generally stimulate milk production. Breastfeeding and ovulation usually don't occur at the same time because these hormones often cause menstruation and ovulation to stop during the first several months of breastfeeding an infant. Many women use this natural infertility as a means of birth control in the months after giving birth, while others wish to resume ovulation in order to get pregnant again as soon as possible. Experts have established certain breastfeeding guidelines that can help women delay or speed the return of menstruation and ovulation after pregnancy.
Medical experts do not yet fully understand the mechanism by which breastfeeding prevents the return of ovulation, but they know that it has to do with hormone production in the mother's body. The hormones that help stimulate lactation often also suppress menstruation. This natural infertility is believed to help prevent the recurrence of pregnancy before the mother's body has fully recovered. Many doctors discourage women from becoming pregnant again while breastfeeding. Physicians generally believe the mother's body may not be able to nourish both a nursing infant and a developing fetus at the same time.
Experts have devised the lactational ammenorrhea method (LAM) as a means of natural child spacing. LAM takes advantage of the gap that usually occurs between the commencement of breastfeeding and the return of ovulation. Women can delay the return of ovulation by following the breastfeeding practices espoused by LAM.
LAM usually works best when the baby is under six months of age. The baby should receive no other nourishment besides his mother's breast milk. Babies six months and older may begin to eat solid foods, but breast milk should remain their primary source of nutrition. Mothers who wish to use breastfeeding in order to delay ovulation are generally advised to let their babies nurse on command, and to allow suckling only from the breast, and never from bottles or pacifiers. Breastfeeding and ovulation generally won't occur at the same time if the baby is less than six months of age, receives all nourishment and comfort suckling from the mother's breast, and is nursed every three to four hours during the day and at least every six hours at night.
Once the baby has reached six months of age, breastfeeding and ovulation are more likely to occur in conjunction. Menstruation and ovulation generally return when the baby has begun sleeping through the night and the mother is breastfeeding less often. Most mothers who use breastfeeding to delay ovulation become fertile again about 15 months after giving birth. Mothers who wish to restore fertility sooner may do so by bottle-feeding or weaning the infant. Mothers who choose not to breastfeed may become fertile again as soon as three weeks after giving birth.