Hatherley L I
Clin Reprod Fertil. 1985 Sep;3(3):197-203.
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.
一项针对273名使用自然计划生育（NFP）的患者进行的为期六年的前瞻性研究（1975 - 1980年）表明，那些既往月经周期不规律的患者，在产后使用排卵法时处于劣势，因为与孕前月经周期规律的女性相比，她们可识别的安全期更少，和/或意外怀孕的可能性更高。8名患者在产后闭经期间怀孕，其中7名是哺乳期母亲，1名是非哺乳期母亲。结合世界卫生组织（WHO，1983年）关于月经周期的一项国际研究结果，讨论了回忆既往月经史时记忆的可靠性。还考虑了自然计划生育中月经事件预测的相关性。
