Distribution of time of first birth in presence of social customs regulating physical separation and coital frequency

Abstract

The interval between marriage and the first birth in India, particularly in rural areas, is much longer than what is observed in western countries. In eastern Uttar Pradesh, the mean interval is observed to be even longer, possibly due to traditional customs such as the female partner's visits to her parents in the early years of marriage and the smaller chance of coition because of the observance of rigid intercourse taboos. Thus the models to explain the length of the interval of marriage to first birth proposed by Western demographers, which assume that the period of cohabitation between marriage and first birth is uninterrupted, often do not describe the data satisfactorily when applied to rural India. In this paper a model to describe data on first birth interval is proposed that takes account of the distributions of timing and periods of physical separation and variation in fecundity with effective marriage duration.; The author refers to literature reviews by Sheps and Menken on studies prior to 1972 and Leridon and Mode for more recent studies of the relationship between first birth and marriage. This study examines the probability distribution of time to first live birth in India and takes into account social customs and taboos that relate to physical separation of spouses and coital regulation. Visits to parents and the period of stay are assumed to interfere with coital frequency in the theoretical model. Data are obtained from the 1987-89 Survey of the Effects of Sociocultural Factors on the Determinants of Fertility in Eastern Uttar Pradesh (rural districts of Varanasi, Ghazipur, and Azamgarh). The sample includes about 350 households and currently married (7 or more years) women aged under 50 years in each religious/caste group for each district. Findings show that the mean duration of cohabitation between return marriage (RM) and the first visit to parents was about 14 months for upper caste Hindus compared to 1-3 months in the other religious/caste groups. The mean duration of stay before the first conception was about 13 months among upper caste Hindus compared to 8-11 months for middle caste Hindus, scheduled castes, and Muslims. Life table estimates are reported for the proportion of women who were still staying with parents during the first visit by months that elapsed since the time of the visit to parents and by age at RM and religion/caste. Life table estimates are given for the proportion of women who had not yet visited parents for the first time by month elapsed since RM and by age of the women. Among upper caste Hindus (Group I), the risk of first conception increased with an increase in age at RM in succeeding years. Among the other religions/castes (Group II), the risk in succeeding years was the same among women aged 14 and 15-16 years. Risk increased among women aged 17-19 years.