Sex ratios and ‘missing women’ among Asian minority and migrant populations in Aotearoa/New Zealand: A retrospective cohort analysis

ABSTRACT Background Recent research from the UK, USA, Australia, and Canada point to male-favouring Sex Ratios at Birth (SRB) among their Asian minority populations, attributed to son preference and sex-selective abortion within these cultural groups. The present study conducts a similar investigation of SRBs among New Zealand’s Asian minority and migrant populations, who comprise 15% of the population. Methods The New Zealand historical census series between 1976-2013 was used to examine SRBs between ages 0-5 by ethnicity. A retrospective birth cohort in New Zealand was created using the Stats NZ Integrated Data Infrastructure from 2003-2018. A logistic regression was conducted and adjusted for selected variables of interest including visa group, parity, maternal age and deprivation. Finally, associations between family size, ethnicity and family gender composition were examined in a subset of this cohort (families with 2 or 3 children). Results There was no evidence of ‘missing women’ or gender bias as indicated by a deviation from the biological norm in New Zealand’s Asian population. However, Indian and Chinese families were significantly more likely to have a third child if their first two children were females compared to two male children. Conclusion The analyses did not reveal male-favouring SRBs or any conclusive evidence of sex-selective abortion among Indian and Chinese populations. Based on this data, we conclude that in comparison to other western countries, New Zealand’s Asian migrant populations presents as an anomaly. The larger family sizes for Indian and Chinese populations where the first two children were girls suggested potentially ‘soft’ practices of son preference. WHAT IS ALREADY KNOWN ON THIS SUBJECT - There are discrepancies in Sex Ratios at Birth (SRB) among the Asian minority migrant populations – particularly Indian and Chinese populations –in countries like Canada, UK, USA. SRBs show a pronounced number of males over female children, suggesting a widespread practice of sex-selective abortions in these communities since the 1970s. - These trends implicitly reflect social norms of gender bias through son preference, and daughter devaluation. WHAT IS BEING ADDED - The present study did not find evidence of skewed SRBs that favour boys over girls among Asian ethnicities. The analyses however did find a tendency for Indian and Chinese families to have larger families especially when the first two children were girls. - Overall, the findings suggest the absence of widespread practices of sex-selective abortion making New Zealand an anomaly relative to other migrant-receiving countries. However, there are still vestiges of son preference that are seen through decisions around family size and gender composition.