Decrease in consanguinity among parents of children born in Norway to women of Pakistani origin: A registry-based study

Aims: To describe the prevalence of consanguinity among Norwegian Pakistani parents in the period from 1995 to 2005. Methods: All first births to women of Pakistani origin in 1995-2005 (n = 1962) were identified by linking the Medical Birth Registry of Norway with information on country of origin and country of birth from Statistics Norway. Prevalence ratios (PRs) and prevalence differences were calculated by multiple binomial regression analyses with adjustment for maternal age and education. Women born in Pakistan who gave birth in Norway in 1995-97 formed the reference group. Results: The proportion of women who were consanguineously related to their co-parent decreased from 45.5% in 1995-97 to 27.3% in 2002-2005 among those who were born in Pakistan, and from 48.3% to 18.8% among women of Pakistani origin who were born in Norway. The proportion of women who were related to their co-parent as first cousin decreased from 37.7% to 24.7% among women born in Pakistan, and from 43.3% to 16.7% among women of Pakistani origin who were born in Norway. The proportion of births to women with an unrelated co-parent increased by 25% for women born in Pakistan (PR = 1.25, 95% confidence interval (CI) 1.12-1.39), and by 53% for women of Pakistani origin born in Norway (PR = 1.53, 95% CI 1.35-1.74). Conclusions: In contrast to previous reports from the UK, our analysis suggests that there is a decrease in the proportion of consanguineously related parents of children born to women of Pakistani origin in Norway.