Age of marriage and length of the first birth interval in a traditional Indian society: life table and hazards model analysis.

The length of the first birth interval is one of the strongest and most persistent factors affecting fertility in noncontracepting populations, with longer intervals usually associated with lower fertility. Compared to Western society, the average length of the first birth interval is much longer in traditional Indian society. Yet Indian fertility rates are higher because of either ineffective family planning procedures or deliberate nonuse of birth control and because of the high proportion of the population that is married. Here, we examine the effects of various sociodemographic covariates (with an emphasis on the role of age at marriage) on the length of the first birth interval for two states of India: Assam and Uttar Pradesh. Life table and multivariate hazards modeling techniques are applied to the data. Covariates such as age at marriage, present age of mother, female's occupation, family income, and place of residence have strong effects on the variation of the length of the first birth interval. For each subgroup of females (classified according to different levels of the covariates), the median length of the first birth interval for the Assam (Bengali-speaking) sample is shorter than that of the Uttar Pradesh (Hindi-speaking) sample.