Specific ultrasound findings associated with fetal chromosome abnormalities

Cytogenetic amniocentesis (CA) has been performed as a reliable prenatal diagnostic method for decades. The aims of the present study were to reveal the frequency of fetal chromosome abnormalities according to medical indications of CA, and to assess the risks of specific abnormal ultrasound findings. Data on chromosome karyotypes of fetuses from 5043 Japanese mothers were collected. Group I comprised 4626 fetuses whose mothers underwent CA due to a variety of parental reasons. Group II comprised 417 fetuses whose mothers underwent CA due to fetal abnormality, abnormality of amniotic fluid volume and fetal growth restriction. The frequency of chromosome abnormalities in Group II (17.7%) was significantly higher than in Group I (1.8%). The frequencies of chromosome abnormalities in Group II singleton fetuses with fetal abnormality, polyhydramnios and fetal growth restriction were 21.5, 22.9 and 19.6%, respectively. By multivariate analyses, we found that cystic hygroma (odds ratio 5.6, 95% CI 2.7-11.6), abnormal extremity (5.0, 1.7-14.4) and cardiovascular abnormality (3.3, 1.1-10.1) were significant variants associated with fetal chromosomal abnormalities. Information revealed in the present study constitutes a beneficial reference for genetic counseling.