Health effects of consanguinity in Pondicherry.

Of 1000 pregnant women studied, consanguinity was observed in 30.8%, with a higher frequency among women from rural areas, and among Hindus. In the consanguineous group, first cousin marriages were present in 47.4%, and uncle niece marriages in 23.4% of women. Coefficient of inbreeding was highest in Harijans (0.0258), followed by non-Brahmins (0.0220) and Brahmins (0.0204). Fertility was not influenced by consanguinity. There was a significantly higher rate of still births and infant mortality in consanguineous matings as compared with non-consanguineous. Total morbidity was higher in the consanguineous group as compared with the non-consanguineous (p less than 0.01), especially that due to neonatal infections and jaundice. There was no significant difference in the prevalence of congenital malformations, chromosomal and genetic disorders between the two groups, although the number of abnormal births in this group was small.