Definition: Congenital cytomegalovirus infection is definitively diagnosed when the virus is isolated from tissue culture. The diagnosis can also be made by histologic study of typical inclusion bodies in biopsy or autopsy specimens, or less reliably by serologic study. Ascites is diagnosed by ultrasound or physical examination.
Prevalence: Congenital cytomegalovirus infection occurs in 0.2 to 2.2% of deliveries12. Approximately 5% of congenitally infected infants have generalized involvement13. We have found reference to eight cases in which ascites, in the absence of other signs of hydrops, was diagnosed in fetuses with cytomegalovirus infection1-8. There have been an additional three cases where similar findings were present in neonates9-11.
Etiology: The cause of ascites in congenital cytomegalovirus infection is not certain. Contributing factors may include low serum protein levels due to hepatic dysfunction and portal obstruction resulting from periportal inflammation14.
Pathogenesis: The exact mode of transplacental passage is uncertain. The virus replicates in fetal tissues producing inflammation, tissue necrosis, and organ dysfunction. Cytomegalovirus hepatitis in the neonate can present with an intense inflammatory response involving the portal triads. In these cases, lobular disarray, degeneration of hepatocytes, and cholestasis are also seen14.
Associated anomalies: Isolated ascites is an uncommon finding in fetuses with cytomegalovirus infection. More commonly observed manifestations with prenatal ultrasound are overt hydrops, cerebral ventriculomegaly, IUGR, and oligohydramnios1,5,6.
Differential diagnosis: Since ascites is often the first manifestation of hydrops, the differential diagnosis for fetal ascites is essentially the same as with generalized hydrops. When hepatomegaly is present, as it was in our patient, primary liver disease or extramedullary hematopoiesis should be considered.
Prognosis: In the eleven previously reported fetal and neonatal cases where ascites was the principle manifestation of cytomegalovirus, three pregnancies were terminated4,6,7, three fetuses were stillborn or died in the first year of life8,10,11, three were alive but had significant sequelae1,5 and two were reportedly normal3,9. In two cases the ascites resolved prior to delivery2,6; however, both showed evidence of other organ damage (Table I). In general, neonates with symptomatic cytomegalovirus infection do poorly, with a high neonatal mortality rate, and a high rate of neurologic handicap in survivors12. Cytomegalovirus hepatitis is reversible in survivors13.
Recurrence risk: Maternal cytomegalovirus infection may reactivate; hence there is a small theoretical risk of recurrence of fetal infection in subsequent pregnancies12.
Management: Fetal antiviral treatment has not been reported. Paracentesis to remove fetal ascites may help to prevent pulmonary hypoplasia3.
MESH Cytomegalic Inclusion Disease BDE 0381 POS 3220 ICD9 771.1 CDC 771.100
Address correspondence to Douglas S. Richards MD, Department of Obstetrics and Gynecology, PO Box 100294, University of Florida College of Medicine, Gainesville, Florida, 32610-0294 Ph: 904-392-2894; Fax: 904-392-6994. ¶ Dept. of Pediatrics, § Dept. of Pathology
Congenital cytomegalovirus (CMV) infection results in considerable neonatal morbidity and mortality. The diagnosis of fetal cytomegalovirus infection has been made on several occasions when a mother has seroconverted, or after the sonographic recognition of characteristic fetal abnormalities. The diagnosis has been confirmed with varying success by performing maternal or fetal serologic tests4,6,15,16, or by culture of the amniotic fluid1,4,6,17. We present a case which was unusual in that the only ultrasound findings were massive ascites, hepatomegaly, and polyhydramnios. Fetal liver failure and thrombocytopenia were diagnosed prenatally by fetal blood sampling. In spite of severe fetal involvement, maternal and neonatal serologic tests did not support a diagnosis of cytomegalovirus infection, neonatal urine culture was negative, and the diagnosis was confirmed only after delivery, at autopsy.
A 14-year-old black primigravida with limited prenatal care came to the hospital at 27 weeks for evaluation following a motor vehicle accident. She had no history of hepatitis or other recent infectious diseases, and had no significant drug exposure. On physical exam she showed no evidence of trauma; however, the fundal height was greater than expected (34 cm). An ultrasound examination revealed polyhydramnios, with an amniotic fluid index of 29 cm (normal at 27 weeks 9.5-22.6 cm)18. There was a large amount of ascites, with elevation of the diaphragm and apparent shortening of the chest (fig. 1).