Anatomy of a Fertility Decline

Fertility has declined substantially on Peninsular Malaysia in the last 30 years, especially for Chinese and Indians. This Note uses retrospective survey data from the Malaysian Family Life Survey to investigate the proximate causes of this fertility decline, with special attention to ethnic differences therein. The authors examine trends, by parity and ethnicity, in lengths of interpregnancy intervals and in their two main component parts — post-partum amenorrhea and menstruating intervals. These changes reflect trends in the major determinants of these components — breastfeeding and contraceptive use, which are also examined. It is found that age at first marriage has increased for all three ethnic groups. Lengths of post-partum amenorrhea have declined, because of reduced breastfeeding, while menstruating intervals have become longer, because of increasing use of modern contraceptives. The amenorrhea/breastfeeding declines and menstruating interval/contraceptive use increases have been most dramatic for Chinese women.