Prenatal sonographic findings in 207 fetuses with trisomy 21.
OBJECTIVE
The objective was to evaluate the contribution of second trimester ultrasound examination to the prenatal diagnosis of trisomy 21 in 207 fetuses with this aneuploidy. The type and frequency of abnormal sonographic findings were determined. Possible multiple malformation patterns, characteristic of trisomy 21 were sought.


METHODS
Singleton fetuses that had prenatal sonography during the second trimester, then underwent cytogenetic evaluation in our institution, made up the study population. The sonographic findings of 207 fetuses with trisomy 21 were analyzed.


RESULTS
Between 1990 and 2004, fetal karyotyping was performed in 22,150 patients for different indications. An abnormal karyotype was diagnosed in 514 cases (2.3%); among them 207 fetuses with trisomy 21 were detected (40.3%). Abnormal sonography was seen in 63.8% of the cases. Structural anomalies were detected in 28.5% of the trisomy 21 fetuses, among them cardiac defects (15.9%), central nervous system anomalies (14.5%), and cystic hygromas (6.8%) were the most common. Of the minor markers, increased nuchal translucency (28%), pyelectasis (20.3%), and shorter extremities (8.7%) were common findings.


CONCLUSIONS
Appropriate diagnosis of structural anomalies, looking for relatively easily detectable minor markers and incorporating fetal echocardiography into the second trimester sonographic protocol, may increase the contribution of mid-trimester ultrasound examination to diagnosing trisomy 21.
Papp
Csaba
C
Department of Obstetrics and Gynecology, Semmelweis University, Faculty of Medicine, 1088 Budapest, Baross u. 27, Hungary. papp@noi1.sote.hu
Bán
Zoltán
Z
Szigeti
Zsanett
Z
Csaba
Akos
A
Lázár
Levente
L
Nagy
Gy Richard
GR
Papp
Zoltán
Z
D004314:Down Syndrome / Q000000981:diagnostic imaging* / Q000235:genetics*; D005260:Female; D005333:Fetus / Q000002:abnormalities*; D006801:Humans; D007621:Karyotyping; D011247:Pregnancy; D011262:Pregnancy Trimester, Second; D016216:Ultrasonography, Prenatal