Hyperechogenic fetal bowel and Down syndrome. Results of a French collaborative study based on 680 prospective cases.
Hyperechogenic fetal bowel is prenatally detected by ultrasound during the second trimester of pregnancy in 0.1% to 1.8% of foetuses. It has been described as a normal variant and has often been associated with severe diseases, notably Down syndrome. The aim of the present study was to determine the risk of trisomy 21 in a prospective study of 680 fetuses with hyperechogenic foetal bowel. Karyotyping was performed on amniotic cells in 632 cases, and outcome was known in 655 cases. A 2.5% risk of Down syndrome and a 1% risk of other severe chromosomal anomalies were observed. Hyperechogenicity was isolated in 11/17 Down syndrome cases, and associated with other ultrasound anomalies in all seven cases of severe chromosomal anomalies. In conclusion, fetal bowel hyperechogenicity indicates a risk of chromosomal anomalies ten-fold higher than that expected on the basis of maternal age, therefore justifying invasive procedures.
Simon-Bouy
Brigitte
B
SESEP, Université de Versailles, Versailles, France.
Muller
Françoise
F
D002869:Chromosome Aberrations; D004314:Down Syndrome / Q000000981:diagnostic imaging* / Q000235:genetics; D005260:Female; D005602:France; D006801:Humans; D007422:Intestines / Q000000981:diagnostic imaging* / Q000196:embryology*; D007621:Karyotyping; D008297:Male; D011247:Pregnancy; D011446:Prospective Studies; D012307:Risk Factors; D016216:Ultrasonography, Prenatal