Timing and sequence of resuming ovulation and menstruation after childbirth.

Abstract This report presents results from a prospective study of post-partum physiology conducted by the Obstetric Department of the Catholic University of Chile during 1965-68. The study was undertaken to gain more detailed knowledge than is currently available about the relationship between a woman's lactation experience and the return of her post-partum reproductive function. 200 mothers were successfully followed and information collected about their intervals from childbirth to first ovulation and to first bleeding day, together with a detailed history of breast feeding. In these histories, days of 'full breast feeding' (infant exclusively breast-fed) are distinguished from days of 'partial breast feeding' (infant given supplementary nutrition besides breast milk). Elaborate pains were taken to establish the date of first ovulation, four different techniques being used concurrently during a series of weekly contacts with each patient.