[Management of isolated increased nuchal translucency: survey among the Pluridisciplinary Centers for Prenatal Diagnosis]

Objectives: The management for isolated increased nuchal translucency (NT) in the first trimester with a normal karyotype and normal Chromosomal Microarray Analysis (CMA) is not consensual. The aim was to perform a survey among the Pluridisciplinary Centers for Prenatal Diagnosis (CPDPN) in France regarding their management of increased NT in the first trimester.

Methods: We conducted a multicenter descriptive survey between September 2021 and October 2021 among the 46 CPDPNs of France.

Results: The response rate was 56.5% (n = 26/46). The NT thickness threshold for which invasive diagnosis testing is performed is 3.0mm in 23.1% of centers (n = 6/26) and 3.5mm in 76.9% of centers (n = 20/26). A CMA was performed alone in 26.9% of centers (n = 7/26) while 7.7% of centers (n = 2/26) did not perform a CMA. The gestational age for the first reference ultrasound scan was 16 to 18 WG in 88.5% of centers (n = 23/26), while it was not performed before 22 WG in 11.5% of centers (n = 3/26). Fetal echocardiography is proposed systematically in 73.1% of centers (n = 19/26).

Conclusion: There is heterogeneity in the management of increased NT in the first trimester among the CPDPNs in France. In case of increased NT on first trimester ultrasound scan, the NT thickness threshold for which invasive diagnosis testing is performed varies from 3.0 mm or 3.5mm depending on the center. Moreover, CMA and early reference morphological ultrasound scan between 16 and 18 WG were not systematically performed, despite the current data suggesting their interest.