Prenatal diagnosis and socioeconomic status in the non-invasive prenatal testing era: A population-based study.

BACKGROUND: Advances in technology can bring great benefits to human health, but their implementation may be influenced by socioeconomic factors, particularly in the field of prenatal screening for Down syndrome.

AIM: To analyse screening test indications for, and diagnostic yield of, invasive prenatal diagnostic testing (PNDx) according to socioeconomic status.

METHODS: Retrospective analysis of population-based data on PNDx and karyotype results for 2014-2015 in the Australian state of Victoria. Women having PNDx < 25 weeks due to combined first trimester screening (CFTS), second trimester serum screening (STSS), or noninvasive prenatal testing (NIPT) results were included. PNDx data were analysed by indication and maternal Index of Relative Socio-economic Advantage and Disadvantage (IRSAD), the latter determined by postcode.

RESULTS: There were 145 206 births in 2014-2015; 1906 women underwent PNDx for the indication of CFTS (70.1%), NIPT (17.8%) or STSS (12.0%). Covariates positively associated with NIPT-indicated PNDx, compared with CFTS-indicated testing, were residence in a region of socioeconomic advantage, metropolitan status and maternal age. Women from the most advantaged regions had higher adjusted odds ratios (aOR) of NIPT-indicated testing compared with women from disadvantaged regions (aOR 5.72, 95% CI: 2.95-11.09). The diagnostic yield of PNDx increased with socioeconomic region, from 14% in the lowest IRSAD quintile to 31.2% in the highest (P < 0.0001).

CONCLUSION: Population-based data reveal significant disparities in screening indications for PNDx and hence, in diagnostic yield, according to socioeconomic region. This finding may have ethical and policy implications for prenatal screening in Australia.