Fertility regulation in nursing women: I. The probability of conception in full nursing women living in an urban setting

Abstract

SummaryOne hundred and thirty healthy women who were willing to breast-feed their babies were followed during the first postpartum year to assess their fertility, lactation and bleeding pattern and examine possible relationships between these variables. Seventy-five women were in full nursing and 22 in partial nursing at the end of the 6th postpartum month. Five hundred and three woman-months and nine pregnancies were recorded during full nursing between the 2nd and the 6th month after delivery. The cumulative probability of pregnancy at the end of 6 months in all full nursing women and in non-amenorrhoeic full nursing women was 10.0% and 27.2% respectively. The corresponding figure for partial nursing women was 40–5%.By the end of the first year, the cumulative probability of pregnancy in full nursing women had increased to 33.9%. Except for the bleeding pattern, no differences were found among full nursing women who did or did not become pregnant.It was concluded that full nursing women living in an urban setting who want to space pregnancies need additional protection at a time that depends upon the level of assurance wanted.