Non-invasive prenatal testing: the new era in reproductive medicine
Important advances in screening for genetic abnormalities have major ethical implications.
In Australia, it is routine practice to offer pregnant women screening for fetal chromosomal and structural abnormalities, and, if serious anomalies are diagnosed, the option of terminating the pregnancy. Screening for chromosomal abnormalities commenced in the 1970s and was initially restricted to women whose pregnancies were considered to be of increased risk because of an obstetric history of aneuploidy or advanced maternal age. Over the past five decades, prenatal chromosome screening has been expanded to encompass the entire obstetric population. However, the commonly used aneuploidy screening tests are dogged by high false-positive rates, typically 4%–5%.1 Confirmation of an increased screening risk for aneuploidy involves diagnostic tests such as amniocentesis or chorionic villus sampling, each associated with low but definite risks of pregnancy loss.
Many women are reluctant to proceed with a diagnostic test after a positive aneuploidy screening result,2 and the ability to assess fetal genetic material without directly sampling the amniotic fluid or placenta has long been a goal of prenatal diagnosis. The recent development of non-invasive prenatal testing (NIPT), a high-level screening test using cell-free fetal DNA, offers the opportunity to markedly reduce the…