Life Table Analysis of Birth Intervals for Bangladesh

Abstract

This article presents a life table analysis of the pattern of birth intervals in Bangladesh. The data were derived from the Bangladesh Fertility Survey conducted in 1975. 93% of women surveyed had their 2nd child within 6 years of the 1st birth with an average birth interval of 30 months. The mean birth interval was 36 months for order 1 and 20 months for orders 2-6. After the 1st birth family size appeared to have no effect on the timing of a subsequent birth. The trimean for 1st births to women who married under age 15 years was 56 months compared with 25 months for those marrying at age 15 or above but this effect disappeared at higher birth orders. The 1st birth interval was higher in rural areas (40 months) than urban areas (35 months) and slightly higher among women with no education. For each birth order the death of the previous child within the 1st year of life increased the proportion of women who had another child and also reduced the interbirth interval. For example the death of the 1st child reduced the average birth interval from 30.8 months to 24.1 months. This suggests that attention to infant mortality control could reduce fertility through increased lactation; however this would also produce an overall increase of net reproduction. The 1st birth interval is considered to be high in Bangladesh probably due to the low mean age at marriage and consequent adolescent subfecundity and sterility. It is suggested that future studies examine components of the birth interval such as postpartum amenorrhea waiting time until conception gestation and time required for fetal wastage.