Late onset of hydrops fetalis following intrauterine parvovirus B19 infection

Parvovirus B19 Intrauterine Infection and Eventration of the Diaphragm

Parvovirus B19 infection in pregnancy may have a poor outcome for the fetus. Ocular anomalies, brain damage with hydrocephalus and central nervous system (CNS) scarring, cleft lip and hypospadias, as well myocarditis and congenital heart disease have been reported. We present a case of a preterm female neonate born with ascites, hydrothorax and congenital diaphragmatic eventration (CDE), with a prenatal diagnosis of congenital diaphragmatic hernia (CDH). The neonate was born prematurely at 32 weeks gestation with caesarean section due to a previous caesarean delivery. She was immediately intubated in the delivery room, transferred in the Neonatal Intensive Care Unit (NICU) and supported with high frequency oscillatory ventilation (HFOV). The diagnosis of CDH was sonographically estimated from the 20th week of gestation and surgical correction was decided. During surgery CDE was diagnosed instead of CDH and despite postoperatively care the neonate developed disseminated intravascular coagulation and finally died in the 40th hour of life. Along with the identification of parvovirus B19 in the pleural fluid by PCR, the biopsy of the diaphragm revealed connective tissue, full of vasculature and absence muscle tissue. Although only cytomegalovirus, rubella, and toxoplasmosis were considered to be associated with CDE, parvovirus B19 might also be related to this congenital diaphragmatic malformation. In CDE, the function of the lungs can be compromised as a consequence of the compression applied by the abdominal organs. The neonatologists should include this condition in their differential diagnosis for a more direct and effective management.

Human Parvoviruses

Parvovirus B19 (B19V) and human bocavirus 1 (HBoV1), members of the large Parvoviridae family, are human pathogens responsible for a variety of diseases. For B19V in particular, host features determine disease manifestations. These viruses are prevalent worldwide and are culturable in vitro, and serological and molecular assays are available but require careful interpretation of results. Additional human parvoviruses, including HBoV2 to -4, human parvovirus 4 (PARV4), and human bufavirus (BuV) are also reviewed. The full spectrum of parvovirus disease in humans has yet to be established. Candidate recombinant B19V vaccines have been developed but may not be commercially feasible. We review relevant features of the molecular and cellular biology of these viruses, and the human immune response that they elicit, which have allowed a deep understanding of pathophysiology.

Parvovirus B19 infection: association with third-trimester intrauterine fetal death

OBJECTIVE

To identify the presence of parvovirus B19 infection as a possible cause of fetal loss in the third trimester.

DESIGN

Prospective study of women experiencing third-trimester intrauterine fetal death (IUFD).

SETTING

All cases of IUFD at Danderyd Hospital from 1992 to 1998.

POPULATION

Ninety-three women with IUFD in 33,759 deliveries (0.3%).

METHODS

Detection of B19 DNA by polymerase chain reaction (PCR) in placental and fetal tissue. Placental pathology and B19-specific immunohistochemistry. Maternal serology in consecutive samples.

RESULTS

Among 93 cases of IUFD, seven (7.5%) had detectable B19 DNA in freshly-frozen placental tissue. The detection of B19 DNA in these tissues was confirmed by detection of B19 DNA in six separately stored paraffin-embedded placental tissues. No other explanations for the fetal deaths were found. None of the women had experienced any clinical signs of infection prior to fetal demise. None of the seven fetuses were hydropic. Histopathologic examination of the placentas revealed only minor abnormalities. Serology on maternal samples at birth revealed delayed or absent B19 IgG responses in five of seven cases. Two women were B19 IgG seropositive at the time of delivery but had unusual infection patterns; persistent viraemia for at least five months before birth in one case and likely persistence or re-infection by B19 in the other.

CONCLUSION

In our study, 7.5% of IUFDs in the third trimester may have been caused by parvovirus B19 infection, without signs of fetal hydrops. This finding indicates that B19 PCR should be included in the routine investigation of IUFD.