Estimation of Detection Rates of Aneuploidy in High-Risk Pregnancy Using an Approach Based on Nuchal Translucency and Non-Invasive Prenatal Testing: A Cohort Study.
OBJECTIVE
The aim was to investigate aneuploidy detection using an approach based on nuchal translucency (NT) and non-invasive prenatal testing (NIPT).


METHODS
This was a cohort study including 5,306 high-risk pregnancies with NT measurements and chorionic villus samples (CVS) tested for full karyotype.


RESULTS
The fetal karyotype was normal in 4,172 (78.6%) cases and abnormal in 1,134 (21.4%), including 1,009 with a likely clinically significant adverse outcome. Universal CVS with full karyotyping would lead to the diagnosis of all clinically significant abnormalities. A policy of relying solely on NIPT would have led to the diagnosis of 88.9% of clinically significant abnormalities. A strategy whereby NIPT is the main method, with CVS reserved for cases with NT ≥3.0 mm, would require CVS in 21.7% of cases, identify 94.8% of significant abnormalities and avoid miscarriage in 41 pregnancies compared to CVS for all.


CONCLUSIONS
A policy of NIPT for increased-risk cases and CVS with full karyotype if the NT was ≥3.0 mm reduced the risk of miscarriage yet still identified 95% of clinically significant aneuploidy.
Fetal Medicine Unit, Academic Department of Obstetrics and Gynaecology, St George's University of London, London, UK.
Asma
A
Khalil
Negar
N
Mahmoodian
Abhijit
A
Kulkarni
Tessa
T
Homfray
Aris
A
Papageorghiou
Amar
A
Bhide
Basky
B
Thilaganathan
D000782:Aneuploidy; D015193:Chorionic Villi Sampling; D025063:Chromosome Disorders / Q000175:diagnosis*; D005260:Female; D006801:Humans; D007621:Karyotyping; D048208:Nuchal Translucency Measurement; D011247:Pregnancy; D011256:Pregnancy Outcome; D018566:Pregnancy, High-Risk; D011296:Prenatal Diagnosis / Q000379:methods*; D012189:Retrospective Studies; D018570:Risk Assessment