Male-biased sex ratios in Australian migrant populations: a population-based study of 1 191 250 births 1999-2015 (2018)

View/ Open
Type of Content
Journal ArticleISSN
0300-57711464-3685
Language
EnglishCollections
- Law: Journal Articles [218]
Abstract
Background: The naturally occurring male-to-female (M/F) ratio at birth is 1.05. Higher ratios found primarily in countries across Asia have been attributed to prenatal sex selection due to son preference. There is growing evidence that sex-selective practices continue following migration; however, little is known about these practices following migration to Australia. Methods: In this population-based study we assessed M/F ratios at birth per mother's country of birth for all registered births 1999-2015 in Victoria, Australia (n = 1 191 250). We also compared the M/F ratio among births to mothers born elsewhere to that of mothers born in Australia, stratified by time period and parity. Results: Compared with the naturally occurring M/F ratio as well as to the M/F ratio among births to mothers born in Australia, there was an increased ratio of male births to mothers born in India, China and South-East Asia, particularly at higher parities and in more recent time periods (elevated M/F ratios ranged from 1·079 to 1·248, relative risks of male birth ranged from 1·012 to 1·084 with confidence intervals between 1·001 and 1·160 and P-values between 0·005 and 0·039). The most male-biased sex ratios were found among multiple births to Indian-born mothers, and parity of two or more births to Indian and Chinese-born mothers in 2011-15. Conclusions: The male-biased sex ratios observed in this study indicate that prenatal sex selection may be continuing following migration to Australia from countries where these practices have been documented. The excess of males among multiple births raises the question as to what role assisted reproduction plays. Findings also suggest that systematic discrimination against females starts in the womb.
Keywords
Australia; relative risk; sex ratio; pregnancy; sex selection; sex preselectionANZSRC Fields of Research
32 - Biomedical and clinical sciences::3215 - Reproductive medicine::321503 - Reproduction44 - Human society::4403 - Demography::440302 - Fertility
44 - Human society::4403 - Demography::440305 - Population trends and policies
16 - Studies in Human Society::1699 - Other Studies in Human Society::169901 - Gender Specific Studies
16 - Studies in Human Society::1604 - Human Geography::160403 - Social and Cultural Geography
Rights
Copyright The Author(s) 2018. Published by Oxford University Press on behalf of the International Epidemiological Association. This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0/), which permits non-commercial re-use, distribution, and reproduction in any medium, provided the original work is properly cited.Related items
Showing items related by title, author, creator and subject.
-
Population and fertility by age and sex for 195 countries and territories, 1950–2017: a systematic analysis for the Global Burden of Disease Study 2017
Murray CJL; Callender CSKH; Kulikoff XR; Srinivasan V; GBD 2017 Population and Fertility Collaborators; Basu A (2018)© 2018 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license Background: Population estimates underpin demographic and epidemiological research and are used to track progress ... -
Understanding population fluctuations through volunteered geographic information and novel indicators: The experience of Rakiura, Stewart Island, New Zealand
Darling, Mathew; Adams, Ben; Orchiston, Caroline; Wilson, Thomas; Bradley, Brendon (2019)In an era of heterogeneous data, novel methods and volunteered geographic information provide opportunities to understand how people interact with a place. However, it is not enough to simply have such heterogeneous data, ... -
The Effect of Area Level Deprivation on Obesity in New Zealand: Analysis of The New Zealand Health Surveys
Kirk RC; Halim, A; Basu, A (2017)