Source
Department of Obstetrics and Gynecology, Rambam Medical Center and Faculty of Medicine, Technion-Israel Institute of Technology, 1 Efron St., Haifa 31096, Israel.
Abstract
PURPOSE:
To describe a series of cases of late-onset fetal nuchal translucency in Down syndrome.
METHOD:
In our practice area, most pregnant women usually undergo 3 different sonographic examinations: a fetal nuchal translucency examination in the 1st trimester and 2 detailed surveys of all fetal organs in the early 2nd trimester and in midpregnancy.
RESULT:
During the study period (2003-2008), we detected 11 fetuses with new appearance of severe thickened nuchal soft tissues (>or=6 mm) at 14-16 weeks' gestation after a normal nuchal screening in the 1st trimester. All of these fetuses had trisomy 21. Associated structural anomalies were observed in 10/11 of the cases. In addition, there were 12 fetuses with new appearance of thickened nuchal soft tissues (<4 mm); all these fetuses had a normal karyotype and were normal at delivery.
CONCLUSION:
Obstetricians should be aware that a nuchal abnormality may first appear only at 14-16 weeks' gestation. Fetal karyotyping is advocated in these cases because of the high probability of Down syndrome.
(c) 2009 Wiley Periodicals, Inc.