Uptake of Noninvasive Prenatal Testing in Chinese Women following Positive Down Syndrome Screening

Abstract

Objectives: To investigate how the introduction of noninvasive prenatal testing (NIPT) influenced women's testing choices following a positive Down syndrome screening. Methods: A retrospective study was conducted to compare differences in the uptake rates of invasive prenatal diagnosis (IPD) or no testing in one public hospital 1 year before (pre-NIPT) and 1 and 2 years after the introduction of NIPT in private in August 2011 using descriptive analysis and a χ² test. Conventional screening was funded publicly, but NIPT was not. Multivariable binary logistic regression was used to determine factors affecting choices. Results: In pre-NIPT and in years 1 and 2 after the introduction of NIPT, 306, 362 and 401 women who screened positive were seen, respectively. In year 1 and year 2, 12.6 and 26.7% of them underwent NIPT while IPD was decreased by 16.3 and 25.6%, respectively (p < 0.001). Both chorionic villus sampling and amniocentesis decreased in year 1, but only the former in year 2. However, the rate of declining further testing was similar before and after NIPT (p = 0.213). In multivariable analysis, first trimester screening, nulliparity and working women were significant predictors of accepting NIPT, while only nulliparity was a predictor of declining IPD (OR = 0.61). Conclusions: Introduction of NIPT resulted in a significant decrease in IPD for 2 consecutive years.

Women's preference for non‐invasive prenatal DNA testing versus chromosomal microarray after screening for Down syndrome: a prospective study

“…[1][2][3][4][5] NIPT can now be used as a secondary test to reduce the need for an invasive test in women with pregnancies screened as being at high risk of Down syndrome, or as an alternative to the traditional first-or second-trimester screening test. NIPT has resulted in almost a 30% reduction in the number of invasive tests performed in Hong Kong,6,7 which is similar to the reduction reported in other centres. [8][9][10] Other factors that influence women's decisions include the procedure-to-result interval, the number of abnormalities assessed, the procedure-related loss rate, and the ability to pay.…”

“…Other factors that influence women's decisions include the procedure‐to‐result interval, the number of abnormalities assessed, the procedure‐related loss rate, and the ability to pay. Although several studies have examined women's choices between invasive tests and NIPT, they were based on hypothetical scenarios or were observational studies with common disadvantages . Women had to choose between NIPT and an invasive test plus karyotyping, without the option of chromosomal microarray (CMA).…”

“…Women had to choose between NIPT and an invasive test plus karyotyping, without the option of chromosomal microarray (CMA). Furthermore, the rate of procedure‐related fetal loss was either not mentioned or was quoted to be 0.5% or higher . Procedure loss rates have been significantly reduced from 0.5–1.0% to 0.1–0.2%, however, whereas a Danish multicentre study indicated that invasive tests were not associated with an increased risk of miscarriage or stillbirth …”

Effect of non-invasive prenatal testing as a contingent approach on the indications for invasive prenatal diagnosis and prenatal detection rate of Down's syndrome

“…As shown in other studies 5,14 and our previous study, 16 the introduction of NIPT was accompanied by a decrease in IPD rate. In the present study, we have further shown that the introduction of NIPT reduced the IPD rate for positive aneuploidy screening without affecting the prenatal detection of Down's syndrome.…”

“…15 Although not as a free service, NIPT has been available in Hong Kong since August 2011. In our previously published study, 16 we showed that the introduction of NIPT as a contingent test resulted in a significant decrease in IPD by 16.3% and 25.6% in the first and second year, respectively. It remained unclear, however, whether this change in practice affected the overall prenatal detection rate of Down's syndrome and whether the indication for IPD because of a scan abnormality was increased.…”