EP07.70: Thickened nuchal translucency with a normal karyotype: management and prognosis

To evaluate the prognosis of the fetuses presenting a thickened nuchal translucency in case of a normal karyotype and how to manage such pregnancies. This was a retrospective and descriptive study held in the Obstetrics and Gynecology Department of the University Hospital Mongi Slim La Marsa, Tunis, between 1 June 2017 and 27 December 2018. Fifteen cases of thickened nuchal translucency with a normal karyotype confirmed by amniocentesis or trophoblast biopsy were studied. Fifteen cases of thickened nuchal translucency were studied. The mean maternal age was 30.7 years. In one case, the karyotype concluded to a trisomy 21. In 5 cases, the thickened nuchal translucency disappeared between 14 and 17 weeks of gestation. Among those, one was diagnosed with achondroplasia and one with a trisomy 8 mosaicism and two had normal pregnancies and delivered healthy newborns. For the fifth patient, the ultrasonographic screening in the second trimester showed the agenesia of the canal of Arantius and delivered a baby with facial dysmorphia. The etiological investigation was refused by the parents. A CGH array was indicated in a patient with persistent nuchal translucency associated with vascular anomalies: a unilateral Notch and a single umbilical artery, which made it possible to rule out a 22q11 microdeletion. We decided to terminate the pregnancy in three cases. The histological study concluded to a cystic hygroma of the neck in two cases and to a complex cardiac malformation in one case. The chromosomal abnormalities found in our study were a Tuner mosaicism and a trisomy 8 mosaicism. In summary, when discussing prenatal findings with parents, we can reassure them that if the karyotype and morphological ultrasound results are normal, and there is no nuchal translucency on follow-up scans, children's developmental outcomes at two years of age are expected to be similar to those of children in the general population.