%0 Journal Article
%T Different sex ratios of children born to Indian and Pakistani immigrants in Norway
%A Narpinder Singh
%A Are Pripp
%A Torkel Brekke
%A Babill Stray-Pedersen
%J BMC Pregnancy and Childbirth
%D 2010
%I BioMed Central
%R 10.1186/1471-2393-10-40
%X We performed a retrospective cohort study of live births in mothers of Indian (n = 1597) and Pakistani (n = 5617) origin. Data were obtained from "Statistics Norway" and the female-to-male (F/M) sex ratio was evaluated among 21,325 children born, in increasing birth order, during three stratified periods (i.e., 1969-1986, 1987-1996, and 1997-2005).A significant low female-to-male sex ratio was observed among children in the third and fourth birth order (sex ratio 65; 95% CI 51-80) from mothers of Indian origin who gave birth after 1987. Sex ratios did not deviate from the expected natural variation in the Indian cohort from 1969 to 1986, and remained stable in the Pakistani cohort during the entire study period. However, the female-to-male sex ratio seemed less skewed in recent years (i.e., 1997-2005).Significant differences were observed in the sex ratio of children born to mothers of Indian origin compared with children born to mothers of Pakistani origin. A skewed number of female births among higher birth orders (i.e., third or later) may partly reflect an increase in sex-selective abortion among mothers of Indian origin, although the numbers are too small to draw firm conclusions. Further research is needed to explain the observed differences in the female-to-male ratio among members of these ethnic groups who reside in Norway.Female infanticide is a method of sexual selection that is practiced in areas of the world where male children are valued over female children. Recent findings based on data from the United Kingdom's national register revealed a low female-to-male ratio at birth to Indian-born mothers living in England and Wales. This skewed sex ratio was observed specifically among higher birth orders [1]. Tendency toward a skewed sex ratio has also been found among families of Asian ethnicity living in Quebec [2].Worldwide, the annual sex ratio is approximately 95 females to 100 males, and may fluctuate somewhat among different races [3]. Many biologica
%U http://www.biomedcentral.com/1471-2393/10/40