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 (≥1:250; HR) or intermediate risk (1:251-1200; 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 (1:251-1200) 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.
Keywords: Cell-free DNA; Down syndrome screening; chromosomal microarray; non-invasive prenatal DNA testing; trisomy.
© 2018 Royal College of Obstetricians and Gynaecologists.