Non-invasive cell-free DNA prenatal screening for trisomy 21 as part of primary screening strategy in twin pregnancies.
Ultrasound Obstet Gynecol
; 2023 Jul 20.
Article
in En
| MEDLINE
| ID: mdl-37470702
ABSTRACT
OBJECTIVES:
The performance of non-invasive prenatal screening using cell-free DNA testing in maternal blood in twin pregnancies is still under-evaluated, while serum marker-based strategies yield poor results. This study aims at assessing the performance of non-invasive prenatal screening for trisomy 21 in twin pregnancies as a first-tier test. The secondary objectives were to assess the failure rate and associated factors.METHODS:
This retrospective cohort study included twin pregnancies for which non-invasive prenatal screening using cell-free DNA was performed as the primary screening strategy between May 2017 and October 2019. We used the NIPT VeriSeq® test for in vitro diagnosis and set a fetal fraction cut-off of 4% for monochorionic pregnancies and 8% for dichorionic ones. Clinical data and pregnancy outcome was collected from either physicians or midwives through a questionnaire or were retrieved directly on site. We calculated the performance of non-invasive cell free DNA screening for trisomy 21 and analyzed failure rate and factors.RESULTS:
We included 2577 multiple pregnancies among which 1885 (84.8%) were retained after excluding vanishing twins and pregnancies without follow-up. Overall, there were six confirmed trisomy 21 cases (0.32%). For trisomy 21, sensitivity was 100% (95% CI, 61-100%) and the false-positive rate 0.2% (95% CI, 0.07-0.6%). The primary failure rate was 4.6% with 4% due to insufficient fetal fraction. After a new blood draw (59.8% of failed cases), failure rate was only 1.5%. Body mass index and chorionicity were significantly correlated with the risk of failure.CONCLUSION:
This study adds further evidence on the high performance of NIPS in twins, as part of the primary screening strategy for trisomy 21, at an extremely low false-positive rate. This article is protected by copyright. All rights reserved.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Type of study:
Diagnostic_studies
/
Observational_studies
/
Risk_factors_studies
/
Screening_studies
Language:
En
Journal:
Ultrasound Obstet Gynecol
Journal subject:
DIAGNOSTICO POR IMAGEM
/
GINECOLOGIA
/
OBSTETRICIA
Year:
2023
Document type:
Article
Affiliation country:
Francia