The significance of choroid plexus cysts, echogenic heart foci and renal pyelectasis in the first trimester.

OBJECTIVE

To determine the significance of certain soft ultrasonographic markers for chromosomal abnormalities in the first trimester.

DESIGN

This was a prospective cross-sectional study.

SETTING

University Department of Obstetrics and Gynaecology, London, UK.

METHODS

A total of 5385 women from an unselected population underwent a detailed assessment of fetal anatomy at 11-14 weeks of gestation (confirmed by crown-rump length) by transabdominal sonography (5.0 MHz) and transvaginal sonography (6.0 MHz) when necessary.

RESULTS

In normal fetuses, the prevalences of choroid plexus cysts, pyelectasis and echogenic heart foci were 2.2, 0.9 and 0.6%, respectively in the first trimester and 2.0, 0.8 and 0.8%, respectively in the second trimester. Pyelectasis (likelihood ratio = 8.0, p = 0.03) and echogenic heart foci (likelihood ratio = 10.3, p = 0.02) were found to be associated significantly with fetal aneuploidy, while choroid plexus cysts were not.

CONCLUSIONS

Although the majority of aneuploidies were detected by increased nuchal translucency and/or the presence of structural abnormalities (78%; 25/32), the use of soft ultrasonographic markers in the first trimester would have increased the overall detection by a further 3%. These data are preliminary and many thousands of pregnancies will need to be examined to determine the significance of the individual markers in different chromosomal abnormalities.