No abstract

A longitudinal prospective study was performed to investigate the total duration of breast-feeding. Three hundred and sixty-six mothers were followed-up until 3 years after delivery. At 1 month 93% were breast-feeding, at 3 months 73%, at 6 months 52%, at 1 year 20% and 1% breast-fed more than 3 years. Correlations were found between duration of breast-feeding and maternal age, education and social class. Mothers who had breast-fed an older child usually breast-fed the next child for a period of similar length. Solid food was most frequently introduced when the infants were 4 months old. At 6 months 4% were still exclusively breast-fed. Breast-feeding has become popular: only 1% did not want to breast-feed at all and 89% of mothers intended to breast-feed their children for 6 months or more. Even though the mothers now breast-feed longer than earlier, only 39% succeeded in breast-feeding for as long as or longer than they had intended.

The duration of postpartum amenorrhoea was studied in a Danish sample of 361 women. The median duration of amenorrhoea was 17 weeks. The 25th and 75th percentiles were 10 and 30 weeks, respectively. A significant correlation was found between the duration of postpartum amenorrhoea and of breast-feeding. However, lactation for more than 9 months did not extend the duration of amenorrhoea. Menstruation before weaning occurred in 57% of the women, and 43% terminated breast-feeding before the first menstruation. Four weeks after weaning menstruation had returned in 79% and by 8 weeks after in 93% of the mothers. At 6 months postpartum, frequency of breast-feeding, and of night-time feeding were determinants of amenorrhoea.