Sex selection and non‐invasive prenatal testing: A review of current practices, evidence, and ethical issues

Abstract

Non‐invasive prenatal testing (NIPT) can determine the sex of the fetus very accurately and very early in gestation. There are concerns that the ease, timing, and accuracy of NIPT sex determination will facilitate sex‐selective termination of pregnancy (TOP). Here, we review current practices, the evidence for a link between NIPT and sex‐selective TOP, and associated ethical issues. Sex‐selective TOP, usually motivated by son preference, has had serious demographic consequences in countries such as India and China. Currently, ultrasound is the primary method by which parents determine the sex of the fetus. The diffusion of ultrasound technology has had a direct impact on the rates of sex‐selective TOP. Although NIPT is currently more costly, it is feasible that increased uptake of this technology could have a similar effect. Partly because NIPT is a relatively recent development in prenatal screening, there is little data on the impact of NIPT on sex selection practices. Evidence that NIPT is playing a role in sex‐selective TOP remains largely anecdotal. Further research is required to assess and quantify TOP resulting from NIPT sex determination. The use of these technologies for sex selection raises a number of ethical issues, in addition to practical demographic consequences.

The Emergence and Global Spread of Noninvasive Prenatal Testing

“…All available tests screen for T21, T18, and T13, with some also offering information about sex chromosome aneuploidies, additional chromosome aneuploidies, and microdeletions despite caution from professional bodies (126). Concerns have been raised about the potential use of NIPT for sex selection, although no data are available (23,47). NIPT is currently being used as both a first-tier test (offered to all pregnant women) and second-tier test (offered to those already identified as high chance 1 ) (53), and there is ongoing uncertainty over where it should sit in the antenatal screening pathway.…”

Sex ratios at birth in Australia according to mother’s country of birth: A national study of all 5 614 847 reported live births 1997–2016

“…The role ultrasound plays in sex selection is well known, and the rise in sex ratios in selected countries have been linked to the increasing availability of ultrasound and other prenatal diagnostic techniques from the 1970s [ 1 , 2 ]. Concerns have been raised that the more recently introduced NIPT test, which only requires a simple maternal blood sample, may have the potential to facilitate pregnancy terminations due to unwanted fetal sex, but evidence is still only anecdotal [ 52 ]. The pathway through selective implantation is less likely in Australia, since sex selection through assisted reproduction is prohibited (unless medically indicated) [ 34 ], and the relatively low prevalence of assisted reproduction (about 1 in 20 infants born).…”

Development of a Specific Monoclonal Antibody to Detect Male Cells Expressing the RPS4Y1 Protein

“…Since the discovery in 1997 of circulating cffDNA in the maternal blood [ 2 ], male sex determination has been the first non-invasive test developed for clinical application. Currently, it is adopted in worldwide healthcare systems [ 32 ] due to the many advantages relied on safety (a simple maternal blood sample required), high sensitivity and specificity (0.989 and 0.996, respectively) [ 33 ], and early (since 7 weeks of gestation) sex determination that has reduced the invasive procedures for the definitive diagnosis by around 50% [ 34 ].…”