Abnormal nuchal findings on screening ultrasonography: aneuploidy stratification on the basis of ultrasonographic anomaly and gestational age at detection.
OBJECTIVE
Our purpose was to determine the specific likelihood of different aneuploidies by gestational age in patients with nuchal folds and simple and septated nuchal membranes.


METHODS
Retrospective database analysis was performed of 158 consecutive patients with a nuchal fold or simple or septated nuchal membrane on either abdominal or vaginal ultrasonography.


RESULTS
Thirty-eight patients with nuchal folds, 65 with simple nuchal membranes, and 55 with septated nuchal membranes were evaluated. Septated nuchal membranes were associated with the highest incidence of karyotypic abnormalities (> 50%). A peak incidence of trisomy 21 (27%) was found in the early midtrimester, leveling off to 11% by the late midtrimester. The late first trimester had a high incidence of trisomy 18 (22%), occurring more frequently than 45,X.


CONCLUSIONS
Ultrasonographic anomalies in the posterior neck are associated with aneuploidy from 21% to 58% of the patients in this selected population. Each anomaly has different risks for aneuploidy type, varying with gestational age at diagnosis.
Landwehr
J B
JB
Department of Obstetrics and Gynecology, Wayne State University/Hutzel Hospital, Detroit, MI 48201, USA.
Johnson
M P
MP
Hume
R F
RF
Yaron
Y
Y
Sokol
R J
RJ
Evans
M I
MI
D000782:Aneuploidy; D002869:Chromosome Aberrations / Q000453:epidemiology; D025063:Chromosome Disorders; D002887:Chromosomes, Human, Pair 18; D000013:Congenital Abnormalities / Q000000981:diagnostic imaging / Q000235:genetics; D004314:Down Syndrome; D005260:Female; D005865:Gestational Age; D006801:Humans; D015994:Incidence; D007621:Karyotyping; D009333:Neck / Q000002:abnormalities* / Q000000981:diagnostic imaging* / Q000196:embryology; D011247:Pregnancy; D012189:Retrospective Studies; D014314:Trisomy; D016216:Ultrasonography, Prenatal