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

ABSTRACT

OBJECTIVE: To examine preferences for follow-up testing in women screened with high or intermediate risk for Down syndrome in the first or second trimester. DESIGN: Prospective cohort study. SETTING: Three public hospitals in Hong Kong, China. SAMPLE Women with pregnancies termed as high risk (≥1250; HR) or intermediate risk (1251-1200; IR) for Down syndrome. METHODS: Women with pregnancies screened as HR were offered the choices of (1) an invasive test plus chromosomal microarray (CMA) to obtain more detailed fetal genetic information; (2) non-invasive cell-free prenatal DNA screening (NIPT) to detect trisomies 13, 18 and 21, and to avoid procedure-related miscarriage; and (3) to decline any further testing. Women received standardised counselling informing them that the reporting times were identical, the procedure miscarriage risk was 0.1-0.2% and that there was no charge for screening. Women with IR pregnancies (1251-1200) were offered NIPT as a secondary screening test. MAIN OUTCOME MEASURES: Uptake rate for NIPT. RESULTS: Three hundred and forty-seven women had pregnancies deemed as HR; 344 (99.1%) women opted for follow-up testing, 216 (62.2%) of whom chose NIPT. Five hundred and seven of 614 women (82.6%) with IR risk chose NIPT. Seven (21%) of 34 women with nuchal translucency ≥3.5 mm opted for NIPT. CONCLUSION: In a setting where reporting times are similar and there is no cost difference between options, approximately 60% of women with pregnancies classed as HR would opt for NIPT, offering simple but limited aneuploidy assessment, over a diagnostic procedure with comprehensive and more detailed assessment. TWEETABLE ABSTRACT 60% of pregnant Chinese women prefer NIPT over CMA when screened as high risk for Down syndrome.