Variation of Ultrasound Findings in the First Trimester Examination of Recurrent Cases With Trisomy 21

Increased nuchal translucency (NT) is present in about 50% of cases with trisomy 21. Very often the nuchal edema evolves in hydrops fetalis until the second trimester. Furthermore, a small amount of cases with a normal NT and trisomy 21 exhibit anatomical anomalies. We present a case of a 21-year-old woman, nulliparous, with a history of one termination of pregnancy and a smoking quitter. The prenatal control was negative for TORCH. During the first trimester scan on the 13th week, the NT was found 2.7 mm, the ductus venosus Doppler was normal, and the nasal bone was present. Hydrops fetalis was present though, and the parents were advised for chorionic villus sampling (CVS), but they opted for termination of pregnancy. The molecular control by QF-PCR showed normal karyotype for 13 and 18, a male fetus, but non-dysjunction trisomy 21 was present. Parental karyotype was advised, but they refused to perform it. One year later, the couple had another pregnancy. On the 12th week scan, the NT was found 1.0 mm, the ductus venosus Doppler was normal, and the nasal bone was present, but encephalocele was also found, and the parents consented again for termination of pregnancy. The new molecular control showed the same results. This time parental karyotype was performed. The father had a normal one, whereas the mother showed reversed p11 and q13 zones in chromosome 2. Genetical consulting and prenatal cytological control was advised in before next pregnancy.