[The risk of conception during lactation]

Abstract

The contraceptive effect of lactation is undisputed. Nursing increases the prolactin level in the serum. This hyperprolactinaemia suppresses all levels of the hypothalamus-hypophysis-ovary axis. The risk of ovulation can be greatly reduced by a proper nursing routine, frequency of nursing being credited with a greater anovulatory effect than duration of nursing. In addition, full nursing increases contraceptive safety. To prevent a drop in the serum prolactin level, nursing should also be done at night-time. Amenorrhoea during the lactation period is one of the most important prerequisites for an adequate contraception. The risk of ovulation increases dramatically, if vaginal bleeding occurs. However, the first cycles in the lactation period are often anovular and characterized by corpus luteum insufficiency. Lactation-induced amenorrhoea, nursing frequency of at least 6 x/day, nursing duration of at least 60 minutes/day, additional feedings of maximum 1 x/day and nocturnal nursing are the requirements for sufficient nursing-induced contraception. Even if these requirements are fulfilled, the risk of ovulation increases with the length of time post partum. Effective contraceptive protection is attained only up to the 9th p.p. week. If high post partum contraceptive safety is required, a mini-pill or micro-pill must be recommended. Lactation can only be recommended as a moderate contraceptive measure even in this case, an additional method (chemico-mechanical) should be initiated 3 months post partum.

PIP: The contraceptive effect of lactation is undisputed. Nursing increases the prolactin level in the serum. The attendant hyperprolactinemia suppresses all levels of the hypothalamus-hypophysis-ovary axis. The occurrence of anovulation is mainly attributed to the negative effect of increased prolactin on the secretion of gonadotropin releasing hormone (GnRH), which results in the suppression of pulsatile luteinizing hormone secretion. It is not known to what effect the suckling stimulus itself influences the GnRH activity on the hypothalamic level. The risk of ovulation can be greatly reduced by a proper nursing routine, the frequency of nursing rather than the duration of nursing being credited with a greater anovulatory effect. The more often and longer nursing occurs daily, the higher the prolactin level and the smaller the risk of ovulation. In addition, full nursing increases contraceptive safety. In a 1972 study, 14% of fully breast-feeding women ovulated compared with 29% of partly breast-feeding women within 16 weeks' postpartum. Full breast feeding assures a 98% rate of protection from pregnancy in the first 6 months' postpartum. To prevent a drop in the serum prolactin level, nursing should also be done at night. Amenorrhea during the lactation period is one of the most important prerequisites for adequate contraception. The first menstrual cycles in the lactation period are often anovular and are characterized by corpus luteum insufficiency. Lactation-induced amenorrhea, nursing frequency of at least 6 times a day, nursing duration of at least 60 minutes/day, additional feedings a maximum of once a day, and nocturnal nursing are the requirements for sufficient nursing-induced contraception. Effective contraceptive protection is attained only up to the 9th week postpartum. If high postpartum contraceptive safety is required, a minipill should be recommended. Even so, lactation can only be recommended as a moderate contraceptive measure, and an additional chemical-mechanical method should be initiated 3 months' postpartum.