Objective: Our objective was to determine the clinical significance of fetal hypoechoic hepatomegaly and serial change of liver sizes.
Methods: The liver sizes of four fetuses with hypoechoic hepatomegaly were serially estimated by liver length, as measured from the dome of the right hemidiaphragm to the tip of the right lobe.
Results: All cases were associated with trisomy 21 or transient abnormal myelopoiesis (TAM). Two cases were trisomy 21 with TAM, one case was a phenotypically normal newborn, who had developed TAM during the fetal period, and the last case was trisomy 21 without TAM. In the last case, it is speculated that TAM had developed and regressed completely before birth. Two cases, whose hepatomegaly had improved before birth, showed good prognosis and the other two cases, in whom improvement had not been observed, resulted in death after birth by liver failure.
Conclusion: These experiences show that one of the differential diagnoses of hypoechoic hepatosplenomegaly is TAM and that the change of live size is a predictor of prognosis.