Cost-effectiveness of ultrasound before non-invasive prenatal screening for fetal aneuploidy

OBJECTIVE

To determine the cost-effectiveness of first-trimester ultrasound before fetal aneuploidy screening with cell-free DNA (cfDNA) compared with screening by cfDNA alone.

METHODS

A decision analytic model was constructed for 400 000 pregnant individuals with advanced maternal age who desired first-trimester aneuploidy screening with cfDNA in the USA, to compare two screening strategies: (1) cfDNA only and (2) ultrasound performed within 4 weeks before cfDNA. Input parameters included probability of fetal aneuploidy, cfDNA performance, desire for diagnostic testing, pregnancy outcomes, and pregnancy and lifetime costs and utilities. The primary outcome measure was the incremental cost-effectiveness ratio (ICER), in terms of cost in 2020 US dollars (USD) per quality-adjusted life year (QALY) gained. Secondary outcomes included procedure-related loss, pregnancy termination, live birth with aneuploidy, live birth with structural anomaly and stillbirth. Discounting was performed at 3% per year with an estimated maternal lifespan of 81 years starting at the age of 35 years. One-way, multiway and Monte Carlo probabilistic sensitivity analyses were performed. All base-case estimates and ranges of uncertainty were derived from the literature. The willingness-to-pay threshold was set at 100 000 USD per QALY.

RESULTS

In the base-case analysis, ultrasound before cfDNA screening was more cost-effective than cfDNA screening without pretest ultrasound, with an ICER of 12 588 USD and higher net monetary benefit (24 241 vs 20 466). The strategy involving ultrasound before cfDNA was more costly by 544 USD but also more effective (by 0.04 QALY) compared with cfDNA alone. Base-case results were robust in sensitivity analyses with the strategy involving ultrasound before cfDNA always remaining the most cost-effective approach with the highest net monetary benefit.

CONCLUSION

First-trimester ultrasound before cfDNA is a more cost-effective strategy for non-invasive prenatal aneuploidy screening compared with cfDNA alone. © 2022 International Society of Ultrasound in Obstetrics and Gynecology.

Utility of ultrasound examination at 10-14 weeks prior to cell-free DNA screening for fetal aneuploidy

OBJECTIVE

To estimate the frequency of unexpected first-trimester ultrasound findings that would alter prenatal management in pregnant women eligible for cell-free (cf) DNA screening because of advanced maternal age (AMA).

METHODS

This was a retrospective cohort study of all AMA women at a tertiary care center who had a 10-14-week ultrasound examination between 1 January 2012 and 27 April 2015. Information on pregnancy dating, obstetric ultrasound examination, prenatal screening and genetic testing were collected from a perinatal database. The primary outcome was an unexpected ultrasound finding in the first trimester that would alter the prenatal screening/testing strategy.

RESULTS

In total, 2337 women met the inclusion criteria, with a total of 2462 fetuses. Sixty-eight (2.9%) women had an anomalous fetus, of which 44 (64.7%) had diagnostic testing. In the entire cohort, a non-viable pregnancy was identified in 153 (6.5%) women. Multiple gestation was identified in 32 (1.4%) women; five had a cotwin demise. Gestational dating was revised for 126 (5.4%) women. Among those who opted for aneuploidy screening (n = 1806), 68.5% had cfDNA screening and 31.5% had first-trimester screening by analysis of maternal serum biomarkers and nuchal translucency thickness. Among those eligible for cfDNA screening, 16.1% (95% CI, 15.0-18.0%; 377/2337) had an ultrasound finding (anomaly, incorrect dating, multiple gestation, non-viable pregnancy) at the time of testing that would have altered the provider's counseling regarding the prenatal screening/testing strategy.

CONCLUSIONS

A substantial proportion of AMA women eligible for cfDNA screening have fetal ultrasound findings that could alter genetic testing strategy and clinical management. This study recommends ultrasound examination prior to cfDNA screening in AMA women. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.