LACTATIONAL INFERTILITY IN FAMILY-PLANNING

The contraceptive effect of breast-feeding is the single most importan t determinant of human population growth rates in traditional societie s without access to modern forms of contraception; lactational amenorr hoea is Nature's contraceptive. Even today, breast-feeding still preve nts more pregnancies than all modern forms of contraception in many de veloping countries. Afferent neural inputs from the nipple pass via th e spinal cord to the hypothalamus, where they cause a local release of beta endorphin. This acts to depress GnRH secretion, thereby inhibiti ng pituitary gonadotrophin secretion, ovarian follicular development, ovulation and menstruation. The hypothalamic beta endorphin release al so inhibits dopamine production, resulting in increased pituitary prol actin secretion. The higher the suckling frequency, the more beta endo rphin that is released and hence the longer the duration of lactationa l amenorrhoea. Lactational amenorrhoea can be relied up to give over 9 8% contraceptive protection to breast-feeding women in the first 6 mon ths postpartum, regardless of their nutritional status or the time of first supplement introduction to the baby. This is because the first p ostpartum menstruation usually precedes the first ovulation during the se early months. Once menstruation has resumed, lactation's contracept ive effect can no longer be relied upon, even though the woman continu es to breast-feed. In breast-feeding women whose amenorrhoea extends b eyond 6 months, there is an increasing tendency for the first ovulatio n to precede the first menstruation, thereby decreasing the reliabilit y of lactational amenorrhoea as a contraceptive. Nevertheless, many wo men who continue to breast-feed may still have up to 1-2 years of good contraceptive protection from prolonged lactational amenorrhoea. Ther e is an urgent need to protect, promote and support breast-feeding in both developing and developed countries, not only for its contraceptiv e effect, but also for its many additional health benefits both for th e mother, and for her child. A simple practical recommendation for dev eloping and developed countries would be that for the first 6 months p ostpartum, the baby should be fed exclusively on breast-milk, and if t he mother is amenorrheic, there is no need for her to use any other fo rm of contraception. Whenever menstruation resumes, other forms of con traception are essential if pregnancy is to be prevented. After the ba by's first teeth have erupted at around 6 months, breast-milk needs to be supplemented with other food, and lactational amenorrhoea needs to be supplemented with another contraceptive in order to ensure a spaci ng between births of at least 2 years, which is highly desirable for t he health of the mother and her children.