Dataset Information

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

ABSTRACT:

Objectives

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.

Setting and participants

The study focused on Asian populations of New Zealand and comparisons were made with NZ European, Māori, Pacific Island and Middle-Eastern, Latin American and African groups. Secondary data were obtained from the New Zealand historical census series between 1976 and 2013 and a retrospective birth cohort in New Zealand was created using the Stats NZ Integrated Data Infrastructure from 2003 to 2018.

Primary and secondary outcome measures

The primary outcome measure was SRBs and sex ratios between the ages 0 and 5 by ethnicity. 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 sex composition were examined in a subset of this cohort (families with two or three 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 female compared with two male children.

Conclusion

The analyses did not reveal male-favouring sex ratios and any conclusive evidence of sex-selective abortion among Indian and Chinese populations. Based on these data, we conclude that in comparison to other western countries, New Zealand’s Asian migrant populations present 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.

SUBMITTER: Simon-Kumar R

PROVIDER: S-EPMC8572392 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Similar Datasets

Project description:The marine-biodiversity assessment of New Zealand (Aotearoa as known to M?ori) is confined to the 200 nautical-mile boundary of the Exclusive Economic Zone, which, at 4.2 million km(2), is one of the largest in the world. It spans 30 degrees of latitude and includes a high diversity of seafloor relief, including a trench 10 km deep. Much of this region remains unexplored biologically, especially the 50% of the EEZ deeper than 2,000 m. Knowledge of the marine biota is based on more than 200 years of marine exploration in the region. The major oceanographic data repository is the National Institute of Water and Atmospheric Research (NIWA), which is involved in several Census of Marine Life field projects and is the location of the Southwestern Pacific Regional OBIS Node; NIWA is also data manager and custodian for fisheries research data owned by the Ministry of Fisheries. Related data sources cover alien species, environmental measures, and historical information. Museum collections in New Zealand hold more than 800,000 registered lots representing several million specimens. During the past decade, 220 taxonomic specialists (85 marine) from 18 countries have been engaged in a project to review New Zealand's entire biodiversity. The above-mentioned marine information sources, published literature, and reports were scrutinized to give the results summarized here for the first time (current to 2010), including data on endemism and invasive species. There are 17,135 living species in the EEZ. This diversity includes 4,315 known undescribed species in collections. Species diversity for the most intensively studied phylum-level taxa (Porifera, Cnidaria, Mollusca, Brachiopoda, Bryozoa, Kinorhyncha, Echinodermata, Chordata) is more or less equivalent to that in the ERMS (European Register of Marine Species) region, which is 5.5 times larger in area than the New Zealand EEZ. The implication is that, when all other New Zealand phyla are equally well studied, total marine diversity in the EEZ may be expected to equal that in the ERMS region. This equivalence invites testable hypotheses to explain it. There are 177 naturalized alien species in New Zealand coastal waters, mostly in ports and harbours. Marine-taxonomic expertise in New Zealand covers a broad number of taxa but is, proportionately, at or near its lowest level since the Second World War. Nevertheless, collections are well supported by funding and are continually added to. Threats and protection measures concerning New Zealand's marine biodiversity are commented on, along with potential and priorities for future research.

Project description:BackgroundInternational and national New Zealand (NZ) research has identified women of South Asian ethnicity at increased risk of perinatal mortality, in particular stillbirth, with calls for increased perinatal research among this ethnic group. We aimed to analyse differences in pregnancy outcomes and associated risk factors between South Asian, Māori, Pacific and NZ European women in Aotearoa NZ, with a focus on women of South Asian ethnicity, to ultimately understand the distinctive pathways leading to adverse events.MethodsClinical data from perinatal deaths between 2008 and 2017 were provided by the NZ Perinatal and Maternal Mortality Review Committee, while national maternity and neonatal data, and singleton birth records from the same decade, were linked using the Statistics NZ Integrated Data Infrastructure for all births. Pregnancy outcomes and risk factors for stillbirth and neonatal death were compared between ethnicities with adjustment for pre-specified risk factors.ResultsWomen of South Asian ethnicity were at increased risk of stillbirth (aOR 1.51, 95%CI 1.29-1.77), and neonatal death (aOR 1.51, 95%CI 1.17-1.92), compared with NZ European. The highest perinatal related mortality rates among South Asian women were between 20-23 weeks gestation (between 0.8 and 1.3/1,000 ongoing pregnancies; p < 0.01 compared with NZ European) and at term, although differences by ethnicity at term were not apparent until ≥ 41 weeks (p < 0.01). No major differences in commonly described risk factors for stillbirth and neonatal death were observed between ethnicities. Among perinatal deaths, South Asian women were overrepresented in a range of metabolic-related disorders, such as gestational diabetes, pre-existing thyroid disease, or maternal red blood cell disorders (all p < 0.05 compared with NZ European).ConclusionsConsistent with previous reports, women of South Asian ethnicity in Aotearoa NZ were at increased risk of stillbirth and neonatal death compared with NZ European women, although only at extremely preterm (< 24 weeks) and post-term (≥ 41 weeks) gestations. While there were no major differences in established risk factors for stillbirth and neonatal death by ethnicity, metabolic-related factors were more common among South Asian women, which may contribute to adverse pregnancy outcomes in this ethnic group.

Project description:Identification of pyraloid species is often hampered by highly similar external morphology requiring microscopic dissection of genitalia. This becomes especially obvious when mass samples from ecological studies or insect monitoring have to be analysed. DNA barcode sequences could accelerate identification, but are not available for most pyraloid species from New Zealand. Hence, we are presenting a first DNA-barcode library for this group, providing 440 COI barcodes (cytochrome C oxidase I sequences) for 73 morphologically-identified species, which is 29% of Pyraloidea known from New Zealand. Results are analysed using the Barcode Index Number system (BIN) of BOLD and the Automatic Barcode Gap Discovery method (ABGD). Using BIN, the 440 barcodes reveal 82 clusters. A perfect match between BIN assignment and morphological identification was found for 63 species (86.3%). Four species (5.5%) share BINs, each with two species in one BIN, of which Glaucocharis epiphaea and Glaucocharis harmonica even share the same barcode. In contrast, six species (8.2%) split into two or more BINs, with the highest number of five BINs for Orocrambus ramosellus. The interspecific variation of all collected specimens of New Zealand Pyraloidea averages 12.54%. There are deep intraspecific divergences (> 2%) in seven species, for instance Orocrambus vulgaris with up to 6.6% and Scoparia ustimacula with 5.5%. Using ABGD, the 440 barcodes reveal 71 or 88 operational taxonomic units (OTUs), depending on the preferred partition. A perfect match between OTU and morphological identification was found for 56 species (76.7%) or 62 species (84.9%). ABGD delivers four or seven species sharing OTUs and four or ten species split into more than one OTU. Morphological re-examination, as well as the analysis of a concatenated dataset of COI and the nuclear markers EF1α and GADPH for species split into more than one BIN or OTU, do not support a higher number of species. Likewise, there is no evidence for Wolbachia infection as a trigger for these sequence variations.