Effect of consanguineous unions on family planning in Pakistan

Background: Consanguineous marriages (e.g., between first or second cousins) are believed to increase spousal compatibility, but increase the risk of adverse health outcomes. Consanguinity increases the risk of recessive genetic disorders. Consanguinity is also related to health behaviors, but this is less well understood. This study examines the effect of consanguinity on contraceptive use in Pakistan. Methods: We analyze the 2009 Pakistan Advertising Impact Survey, which includes a representative sample of married men (n=1,606). Logistic regression is used to estimate the effect of consanguinity on the likelihood that men currently use condoms for family planning, after controlling for other predictors. Results: 59.8% of men are in consanguineous unions (26.7% are paternal first cousins, 26.1% maternal first cousins, 7.0% second cousins). 21.1% of men in non-consanguineous unions use condoms, compared to 16.4% for maternal first cousins, 12.7% for paternal first cousins, and 8.7% for second cousins. Men in paternal cousin marriages or second-cousin marriages have lower condom use than unrelated couples (OR=.57,p<.01; OR=.49,p<.05). This effect cannot be attributed to location/culture, fertility and fertility preferences, family planning attitudes and religious beliefs, spousal communication about FP or female autonomy. However, after controls for knowledge of a condom source, perceived condom effectiveness and wealth, the effect of consanguinity disappears. Conclusion: Paternal cousin and second cousin marriages in Pakistan have lower condom use not because of cultural differences in fertility preferences or family planning attitudes, but rather because they are poorer, less likely to know a condom source and to believe they are effective.