Lactational amenorrhea method

The lactational amenorrhea method (LAM) is a method of avoiding pregnancies which is based on the natural postpartum infertility that occurs when a woman is amenorrheic and fully breastfeeding. If not combined with chemicals or devices, LAM may be considered natural birth control or natural family planning.

Breastfeeding infertility
For women who meet the criteria (listed below), LAM is 98% effective during the first six months postpartum.
 * Breastfeeding must be the infant’s only (or almost only) source of nutrition. Feeding formula, pumping instead of nursing, and feeding solids all reduce the effectiveness of LAM.
 * The infant must breastfeed at least every four hours during the day and at least every six hours at night.
 * The infant must be less than six months old.
 * The woman must not have had a period after 56 days post-partum (when determining fertility, bleeding prior to 56 days post-partum can be ignored).

Ecological breastfeeding is a stricter form of LAM developed by Sheila Kippley, one of the founders of the Couple to Couple League. Studies have shown it has a 1% failure rate in the first six months postpartum, and a 6% failure rate before the woman’s first postpartum menstruation. The Seven Standards of ecological breastfeeding are slightly different from the LAM criteria:
 * Breastfeeding must be the infant’s only source of nutrition – no formula, no pumping, and (if the infant is less than six months old) no solids.
 * The infant must be pacified at the breast, not with pacifiers or bottles
 * The infant must be breastfed often. The standards for LAM are a bare minimum; more frequency is better. Scheduling of feedings should be avoided.
 * Mothers must sleep with their infants – in the same room, if not in the same bed.
 * Mothers must not be separated from their infants for more than three hours a day.
 * Mothers must take daily naps with their infants.
 * The woman must not have had a period after 56 days post-partum (bleeding prior to 56 days post-partum can be ignored).

Return of fertility
Return of menstruation following childbirth varies widely between individuals. The closer a woman's behavior is to the Seven Standards of ecological breastfeeding, the later (on average) her cycles will return. Average return of menses for women following all seven criteria is 14 months, with some reports as soon as 2 months and others as late as 42 months.

Although the first post-partum cycle is sometimes anovulatory (this reduces the likelihood of becoming pregnant again before having a post-partum period), subsequent cycles are almost always ovulatory and therefore must be considered fertile. However, some women find that breastfeeding interferes with fertility even after ovulation has resumed. Luteal phases too short to sustain pregnancy are a common example.

Couples who desire spacing of 18 to 30 months between children can often achieve this through breastfeeding alone.