Is the mothers' country of birth associated with the sex of their offspring in England and Wales from 2007 to 2011?

BACKGROUND: Preference for sons in India has resulted in a skewed sex ratio at live birth, probably as a consequence of female feticide. However, it is unclear if these cultural preferences are also currently present in communities who have emigrated from India to England and Wales.

METHODS: Data of all live births in England and Wales from 2007-2011 were obtained from the Office of National Statistics. A logistic regression analysis was used to compare the probability of having a male infant in mothers born inside the United Kingdom (UK) to those born outside the UK, stratified by mothers' region and country of birth.

RESULTS: Mothers born in India were not observed to be giving birth to disproportionately more boys than mothers that were born in the UK (Odds Ratio OR: 1.00, 95% Confidence Interval CI: 0.98-1.02), although an excess of male births were observed in mothers born in South-East Asia (OR 1.03; 95% CI: 1.01-1.05, p = 0.005), the Middle East (OR 1.02; 95% CI: 1.00-1.05, p = 0.047), and South America (1.04; 95% CI: 1.00-1.07, p = 0.025). Mothers who were born in Africa were found to be less likely to give birth to boys than girls when compared to mothers born in the UK (OR: 0.98, 95% CI: 0.97-0.99), and this observation was attributable to women born in East and West Africa.

CONCLUSION: There was no evidence of an excess of males born to women from India in England and Wales. An excess of males were observed in mothers born in South-East Asia, the Middle East and South America. Women born in Africa are less likely to give birth to boys than UK born mothers, an observation that is consistent with previous data.