VP30.13: Correlation between fetuses with increased nuchal translucence and karyotyping in invasive diagnostic testing

Le résumé fourni par la source

To analyse the correlation between fetuses with increased nuchal translucency (NT) and the final karyotype in an invasive test. Pregnant women with elevated nuchal translucency (NT > p95) and an invasive test (amniocentesis/chorionic biopsy) performed in our centre from January 2015 to December 2020. 13,165 first trimester combined screenings were performed. 134 of these fetus had an elevated nuchal translucency and an invasive diagnostic testing (chorionic villus sampling or amniocentesis) was performed (1.02%). Considering all first trimester combined screenings, 113 had a high risk probability of chromosomal diseases (> 1/270), 13 had an intermediate risk (1 /270-1000) and the remaining 8 a low risk y (<1/1000). 67 cases had abnormal karyotype (50%) while 66 had a normal karyotype (49.25%) and in 1 case a sufficient sample was not obtained for the analysis. Considering the 67 cases with genetic diseases, 40 had trisomy 21/Down syndrome (62.5%), 11 had trisomy 18/Edwards syndrome, 4 cases had 45X0-monosomy/Turner syndrome, 4 cases had trisomy 13/Patau syndrome, 1 case had trisomy 16, 1 case had trisomy 17, 1 case had 69XXY triploidy and the remaining 5 cases had another genetic disease. Considering the 66 cases with normal karyotype, arrays were performed in 40 women (60.6%) and in 3 of them there was an alteration (Williams-Beuren syndrome, Duchenne muscular dystrophy and one unknown syndrome). Most of the cases with genetic diseases (N: 64, 95,52%) presented a high risk in first trimester screening, while the remaining 3 cases presented a low risk. Most of the cases with normal karyotype (N:49, 74,24%) presented a high risk probability of chromosomal diseases. Increased nuchal translucency greatly increases the risk in calculating the chromosomal disease index. More than half of the cases (50.75%) with nuchal translucency above the 95th percentile that underwent an invasive test had an abnormal karyotype.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.