Lactational Amenorrhea - Period While Breastfeeding

Lactational amenorrhea is the temporary postnatal infertility that occurs when a woman is amenorrheic (not menstruating) and fully breastfeeding.

Breastfeeding infertility

For women who follow the suggestions and meet the criteria (listed below), LAM is >98% effective during the first six months postpartum.

Breastfeeding must be the infantâ€™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 mother must not have had a period after 56 days post-partum (when determining fertility, bleeding prior to 56 days post-partum can be ignored).
And to take full advantage of LAM, it is best that the baby's face not be covered when feeding. Routinely covering the baby reduces the baby's access to oxygen and visual contact with the mother, which trains the baby to speed up the suckling process and thus reduces the time period, rendering LAM less effective.

If not combined with barrier contraceptives, spermicides, hormonal contraceptives, or intrauterine devices, lactational amenorrhea method (LAM) may be considered natural family planning by the Roman Catholic Church.

Physiology

Breastfeeding delays the resumption of normal ovarian cycles by disrupting the pattern of pulsatile release of GnRH from the hypothalamus and hence LH from the pituitary. The plasma concentrations of FSH during lactation are sufficient to induce follicle growth, but the inadequate pulsatile LH signal results in a reduced estradiol production by these follicles. When follicle growth and estradiol secretion does increase to normal, the suckling stimulus prevents the generation of a normal preovulatory LH surge and follicles either fail to rupture, or become atretic or cystic. Only when the suckling stimulus declines sufficiently to allow generation of a normal preovulatory LH surge to occur will ovulation take place with the formation of a corpus luteum of variable normality. Thus suckling delays the resumption of normal ovarian cyclicity by disrupting but not totally inhibiting, the normal pattern of release of GnRH by the hypothalamus. The mechanism of suckling-ind uced disruption of GnRH release remains unknown.

Return of fertility

Return of menstruation following childbirth varies widely among individuals. A strong relationship has been observed between the amount of suckling and the contraceptive effect, such that the combination of feeding on demand rather than on a schedule and feeding only breast milk rather than supplementing the diet with other foods will greatly extend the period of effective contraception. 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 after childbirth, with some reports being as soon as 2 months while others are as late as 42 months. Couples who desire spacing of 18 to 30 months between children can often achieve this through breastfeeding alone.

Although the first post-partum cycle is sometimes anovulatory (reducing 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 being too short to sustain pregnancy is a common example.