Determinants of consanguinity and inbreeding coefficient in the multiethnic population of Mardan, Khyber Pakhtunkhwa, Pakistan

Background: Despite the high sociocultural preferences in contracting marriages among close relatives in Pakistan, marked regional differences exist in the prevalence of consanguinity. There is great interest to elucidate the sociodemographic variables underlying the heterogeneity in consanguinity prevalence in the various populations. The present study was conducted in the Mardan district of Pakistan, the second largest multiethnic Pashtun metropolis. Objective: To find determinants of consanguineous unions. Methods: In a cross-sectional study design, a convenience sample of 1,202 ever-married men from 3 tehsils of Mardan district was recruited in an unelected manner and data regarding their marital union types and sociodemographic variables were obtained by a structured interview. Descriptive statistics and multivariable logistic regression analyses were used. Results: Consanguineous unions accounted for 44% of all marriages, and the inbreeding coefficient was calculated as 0.0258. Regression analyses revealed that 6 variables were significant predictors of consanguinity, namely, tehsil, age, year of marriage, caste (zaat/biradari) system, area of house, and marriage arrangement of the respondent, while 6 other variables, namely, rural/urban origin, literacy, occupation, monthly income, household type, and number of family members, were not found to be significant. Regression analyses showed that there were different combinations of variables predictive of consanguinity among the various tehsils. Conclusions: The prevalence of consanguinity in the Mardan district was found to be lower than that in many other districts of Pakistan. National regional differences exist in consanguinity, and the combination of predictive factors varies greatly.