Breastfeeding The fertility-regulating effect of breastfeeding is known to be underestimated. This is mainly due to the lack of knowledge of the events associated with breastfeeding that determine its contraceptive effect. It is now known that breastfeeding in itself is not a particularly effective or reliable means of contraception. On the other hand, the period of amenorrhea associated with breastfeeding, commonly referred to as lactation amenorrhea, provides an important degree of contraceptive effect. Physiology of the contraceptive effect of breastfeeding„h Endocrine responses to breastfeeding The physiological response to breastfeeding is not local, but is mediated at a hormonal level through neural signals afferent to the brain from receptors in the nipple. The secretion of two pituitary hormones, oxytocin and prolactin, into the circulatory system marks the mother's primary response to breastfeeding. Leak et al. reported the continued presence of a vigorous oxytocin response during long-term breastfeeding (up to one year). Oxytocin is secreted by specialized nerve endings in the posterior pituitary and participates in the milk ejection reflex, while prolactin is secreted by cells in the anterior pituitary and appears to be responsible for coordinating the complex biochemical processes involved in milk production.No reports have been found that may attribute oxytocin's ability to interact with the reproductive system. In contrast to oxytocin's apparent lack of interaction, prolactin can influence reproduction at multiple sites including the hypothalamus, pituitary gland, and ovaries. However, it is unclear to what extent the direct effects of prolactin are... half of the article... Obstetrics and Gynecology, vol.62, pp.567-589, 1992.Books„h Howie .PW, "Synopsis of the breastfeeding and fertility research,” Breastfeeding and Natural Family Planning, edited by Mary Shivanandan, pp.7-21, KM Associates, Bethesda, MD, 1986.„h La Leche League International, “The Womanly Art of Breastfeeding", La Leche League International, Franklin Park, IL, 1981, 3rd edition."h McNeilly.AS, Glasier.A. & Howie.PW, "Endocrine Control of Lactational Infertility", Maternal Nutrition and Lactation Infertility lactation, ed. Dobbing.J., pp.1-19, Nestlé Nutrition, Raven Press, New York, 1985.„h Bongaarts.J. & Potter.RG, "Fertility, biology and behavior", Academic Press, New York , 1983. "h Kippley.SK, "Breastfeeding and Natural Spacing of Babies: How Ecological Breastfeeding Spaces Babies," The Couple to Couple League International, Inc., Cincinnati, 1989.