Hypoechoic Liver: A Promising Soft Marker in Screening for Trisomy 21

Abstract Hypoechoic liver, although a known association in Down syndrome fetuses, is scarcely reported in prenatal literature. This article examines the incidence of hypoechoic liver in Down syndrome fetuses and correlates its association with the presence of other established second-trimester soft markers for trisomy 21. Retrospective analysis of 547 high-risk cases for aneuploidy where invasive testing was done between 16 and 22 weeks of gestation was included in the study. Fetal liver was evaluated in the coronal or parasagittal sections of the fetus, using a routine convex probe (1–5 MHz). The liver was considered hypoechoic when its echogenicity was less than that of the adjacent lung and bowel, with conspicuous visualization of the diaphragm. Out of the 45 cases of proven trisomy 21, 55.5% had hypoechoic liver, 62% had absent nasal bone (NB), and 48.8% had increased nuchal translucency (NT)/nuchal fold thickness (NFT). The other soft markers were identified in less than 10% of trisomy 21 cases. Hypoechoic liver was coexistent with absent NB in 20/25 (80%) and increased NT/NFT in 15/25 (60%) of trisomy 21 cases, the two being the most common associations. Hypoechoic liver was not identified as an isolated marker in Down syndrome fetuses. Hypoechoic liver was seen only in 4/469 (0.8%) of the normal fetuses. The presence of hypoechoic liver in more than 50% of the cases with trisomy 21 appears to be a significant association. Further prospective studies are required to assess the potential of hypoechoic liver as a soft marker in Down syndrome screening.