Duration of postpartum amenorrhea in successive pregnancies

In a previous study concerning mothers who were delivered of babies in 1963, it was shown that although lactation increaud the over-all duration of amenorrhea, a considerable number of women menstruated early despite breast feeding. The hypothesis is advanced that women present a consistent postpartum amenorrhea pattern. For those women who gave birth to a subsequent child prior to December, 1965, data were again collected concerning duration of lactation and postpartum amenorrhea. It was found that women who experienced relatively long amenorrhea with one baby tended to do the same with the next baby, and women who experienced relatively short amenorrhea tended to repeat that pattern. The hypothesis seems to be confirmed.