Luteal phase abnormalities in early menstrual cycles after pregnancy have been shown to cause confusion in the practice of natural family planning (NFP) for some patients and to restrict severely the number of late infertile days available to others. The cause of the abnormalities is uncertain but appears to be related to the nursing status of the patient.
Indirect evidence of the occurrence of ovulation, which is generally accepted, is an increase in plasma or serum progesterone. Pelvic ultrasonography can estimate the probable time of ovulation within 12 h. There is a close association between the rise in progesterone, luteinizing hormone (LH) and oestrogen peaks and ovulation. A WHO study reported that ovulation occurred at a median time of 8 h after the rise in plasma progesterone, 15 h after the LH peak and 24 h after the oestrogen peak. The basal body temperature (BBT) method is the most effective in determining the premenstrual infertile period, but it is unreliable for an accurate determination of ovulation and the postmenstrual infertile period. Nor is BBT an effective method of predicting ovulation during postpartum lactational amenorrhoea. Therefore, BBT is usually used as a secondary indicator of ovulation and is combined with more reliable indicators. Observed changes in cervical mucus patterns can be used to define the probable fertile period, although this method produces a wide range of days. The peak mucus symptom is closely correlated with ovulation. Mucus symptoms can be used as a guide for the timing of blood or urine samples for estimation of LH, oestrogen and progesterone or their metabolites. Symptothermal methods incorporate other symptoms such as cervical changes, intermenstrual pain, breast tenderness and backaches, but these are secondary signs of ovulation and are recommended to be used in conjunction with mucus and BBT.
Fertility AwarenessLactational InfertilityReturn of FertilityNFP Use-Effectiveness
The use-effectiveness of natural methods of family planning in lactation is evaluated by comparing the incidence of unplanned pregnancies in a group of nursing mothers practising these methods with the incidences reported previously in surveys of breastfeeding women using no contraception. The complexity of the physiological processes involved in the resumption of ovulation after term pregnancy is discussed in relation to NFP and the problems encountered by its users in the context of normal family life. The serum prolactin and gonadotrophin levels are correlated with the postpartum interval and nursing status of the participants and discussed in relation to NFP after childbirth.
A prospective six-year study (1975-1980) of 273 patients, monitored in the use of natural family planning (NFP), has shown that those with previously irregular menstrual cycles are disadvantaged in the subsequent use of the ovulation method after pregnancy in that they have fewer recognizable safe days and/or are more likely to have unplanned pregnancies than women who had regular cycles prior to pregnancy. Eight patients, seven nursing and one non-nursing mother, conceived during postpartum amenorrhoea. The reliability of memory in the recall of previous menstrual histories is discussed in relation to the results of an international study of menstrual cycles by the World Health Organization (WHO 1983). The relevance of prediction of menstrual events in natural family planning is also considered.
A preliminary study of 'screened' women with two consecutive miscarriages revealed an incidence of abortion in 47.4% in a subsequent pregnancy whilst hCG therapy in a similar group of women where biochemical monitoring with plasma progesterone suggested a potentially jeopardized pregnancy resulted in a continuing pregnancy in 92.3% of treated women. An urgent need for a true randomized double-blind evaluation of this therapy has been established in order to re-examine the therapeutic nihilism which currently pervades the management of women with recurrent abortion.