parity, and introduction of supplemental foods into the infant's diet among others which can influence return of fecundity following pregnancy and childbirth and thus the contraceptive benefits of lactational amenorrhea are not always reliable but are evident and variable among women. Couples who desire spacing of 18 to 30 months between children can often achieve this through breastfeeding alone, though this is not a foolproof method as return of menses is unpredictable and conception can occur in the weeks preceding the first menses. 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. For women exclusively breastfeeding ovulation tends to return after their first menses after the 56 days postpartum time period. Supplementing nutritional intake can lead to an earlier return of menses and ovulation than exclusive breastfeeding. Nursing more frequently for a shorter amount of time was shown to be more successful in prolonging amenorrhea than nursing longer but less frequently. The continuing of breastfeeding, while introducing solids after 6 months, to 12 months were shown to have an efficiency rate of 92.6 – 96.3 percent in pregnancy prevention. Because of this some women find that breastfeeding interferes with fertility even after ovulation has resumed. The Seven Standards: Phase 1 of Ecological Breastfeeding Breastfeed exclusively for the first six months of life; don’t use other liquids and solids, not even water. Pacify or comfort your baby at your breasts. Don’t use bottles and don’t use pacifiers. Sleep with your baby for night feedings. Sleep with your baby for a daily-nap feeding. Nurse frequently day and night, and avoid schedules. Avoid any practice that restricts nursing or separates you from your baby. Phase 1 is the time of exclusive breastfeeding and thus usually lasts six to eight months. Use as birth control For women who follow the suggestions and meet the criteria (listed below), lactational amenorrhea method (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 mother must not have