The purpose of this study was to examine the natural history and differential diagnosis of ultrasound-detected, isolated fetal
ascites. Retrospective review of our patient data base, from 1989 to 1993, revealed 18 patients with fetal
ascites diagnosed sonographically. Fetuses presenting with generalized
hydrops were excluded. One of the 18 fetuses with
ascites had a
chromosomal abnormality (
trisomy 21), four fetuses had intrauterine
infections, seven had gastrointestinal processes, two had genitourinary tract abnormalities, and four were labelled as 'idiopathic' (all four resulting in normal neonates). Seventeen of 18 fetuses survived; there was one
fetal demise secondary to active
syphilis. One fetus with
parvovirus infection required
intrauterine transfusion and did well. Two infants are developmentally retarded, including one with
trisomy 21 and one with
microcephaly secondary to
cytomegalovirus infection. Fourteen of 18 fetuses had documented in-utero resolution of the
ascites. Eleven of the 18 were associated with
polyhydramnios sometime during fetal life. None of the fetuses developed
hydrops. In conclusion, fetal
ascites can result from many different aetiologies, including gastrointestinal and genitourinary anomalies.
Chromosomal abnormalities and viral aetiologies must also be considered. Fetuses who have isolated
ascites can have a good outcome with resolution of the
ascites antenatally.