Introduction: Cytomegalovirus (CMV) is the leading cause of congenital infection worldwide. Data about the management of CMV infection in pregnant women are scarce, and treatment options are very limited. The aim of the study is to investigate the effectiveness of cytomegalovirus hyperimmune globulin (CMV-HIG) for the prevention and treatment of congenital CMV (cCMV) infection.
Materials and methods: A retrospective observational study was conducted in three tertiary hospitals in Madrid. In the period 2009-2015, CMV-HIG (Cytotect® CP Biotest, Biotest) treatment was offered to all pregnant women with primary CMV infection and/or detection of CMV-DNA in amniotic fluid in participating centers. Women were divided into prevention and treatment groups (PG and TG, respectively). Those with primary CMV infection who had not undergone amniocentesis comprised the PG and received monthly CMV-HIG (100 UI/kg). If CMV-DNA was subsequently detected in amniotic fluid, one extra dose of CMV-HIG (200 UI/kg) was given 4 weeks after the last dose. Those women were considered to be part of the PG group despite detection of CMV-DNA in amniotic fluid. In the case of a negative result in CMV-DNA detection in amniotic fluid or if amniocentesis was not performed, monthly HIG was given up to the end of the pregnancy.
Results: Thirty-six pregnant women were included. Median gestational age at birth was 39 weeks (interquartile range: 38-40) and two children (5.5%) were premature (born at 28 and 34 weeks' gestation). Amniocentesis was performed in 30/36 (83.4%) pregnancies and CMV PCR was positive in 21 of them (70%). One fetus with a positive PCR in amniotic fluid that received one dose of HIG after amniocentesis presented a negative CMV-PCR in urine at birth, and was asymptomatic at 12 months of age. Twenty-four children were infected at birth, and 16/21 (76.2%) presented no sequelae at 12 months, while two (9.5%) had a mild unilateral hearing loss and three (14.3%) severe hearing loss or neurological sequelae. Seventeen women were included in the PG and 19 in the TG. In the PG 7/17 (41%) fetuses were infected, one pregnancy was terminated due to abnormalities in cordocentesis and one showed a mild hearing loss at 12 months of age. In the TG, 18/19 children (95%) were diagnosed with cCMV, while the remaining neonate had negative urine CMV at birth. Eight out of the 19 fetuses (42.1%) showed CMV related abnormalities in the fetal US before HIG treatment. Complete clinical assessment in the neonatal period and at 12 months of age was available in 16 and 15 children, respectively. At birth 50% were symptomatic and at 12 months of age, 4/15 (26.7%) showed a hearing loss and 3/15 (20%) neurologic impairment. Fetuses with abnormalities in ultrasonography before HIG presented a high risk of sequelae (odds ratios: 60; 95%CI: 3-1185; p = .007).
Discussion: Prophylactic HIG administration in pregnant women after CMV primary infection seems not to reduce significantly the rate of congenital infection, but is safe and it could have a favorable effect on the symptoms and sequelae of infected fetuses. The risk of long-term sequelae in fetuses without US abnormalities before HIG is low, so it could be an option in infected fetuses with normal imaging. On the other hand, the risk of sequelae among infected fetuses with abnormalities in fetal ultrasonography before HIG despite treatment is high.
Keywords: Congenital cytomegalovirus; fetal infection; hearing loss; hyperimmune globulin.