Has Noninvasive Prenatal Testing Impacted Termination Of Pregnancy And Live Birth Rates Of Infants With Down Syndrome? Editorial Comment

Noninvasive prenatal testing (NIPT) for aneuploidy using cell-free DNA (cfDNA) has become widely available and popular for detection of Down syndrome (DS) because of its high sensitivity (99%) and specificity (99.5%). The acceptance of NIPT as an alternative to the first-trimester combined test has greatly reduced the use of invasive prenatal diagnostic testing. Widespread implementation of NIPT may result in an increase in parents opting for prenatal testing and subsequent reduction in those born with DS as pregnancies are terminated following a high-risk result.This literature review aimed to determine the impact that the introduction of NIPT has had on the number of parents choosing to continue their pregnancy following detection of DS. A systematic search of articles related to NIPTand published from when NIPT entered clinical practice (January 1, 2011, to September 25, 2017) was conducted using the PubMed database. A separate, similar search was conducted to establish country-specific abortion rates prior to the introduction of NIPT. Two audits on termination rates following detection of high risk for DS by NIPT, calculated as a proportion of all pregnancies, were conducted in the United Kingdom and Singapore.A total of 14 studies were included in review. The studies' objectives and design were diverse, 8 prospective and 6 retrospective, whereas only 1 aimed to determine pregnancy outcome and patient decision making following NIPT. The data showed that a significant proportion of pregnancies where NIPT indicated a high risk of DS were continued to live birth in the United States, the United Kingdom, and the Netherlands, whereas there were no live births with DS in the studies from China, Hong Kong, Taiwan, France, and Spain. The audit in Singapore found that 2 of 6 pregnancies were continued to live birth following a high-risk NIPT result, whereas the UK audit found 15 of 43 continued the pregnancy.This study found that many pregnancies were continued to live birth despite receiving a high-risk diagnosis for DS using NIPT. The results also found that the rate of abortion since the clinical implementation of NIPT is unchanged or slightly decreased compared with historical rates. There were numerous instances of women receiving a high-risk result from NIPT and declining to undergo confirmatory invasive testing. These situations suggest some women's intent to undergo NIPT for the sake of obtaining information about the health of their child, however, and unwillingness to risk miscarriage or pursue termination despite the results. Participant numbers were low in many of the studies included, weakening the ability of this review to draw an association between modern and historical termination rates. Larger-scale population-based studies are needed to determine the effect of NIPT on the rates of children born with DS.