Prevention of maternal-fetal transmission of CMV by hyperimmunoglobulin (HIG) administered after a primary maternal CMV infection in early gestation

Objective:

To examine the efficacy of biweekly hyperimmunoglobulin (HIG) administration to women with first trimester CMV infection for preventing maternal-fetal transmission of CMV.

Methods:

Subjects were 40 pregnant women with a primary CMV infection with a median gestational age at diagnosis of 9.6 weeks with a range of 5.1 to 14.3 weeks' gestation. On average, HIG administration started at 11.1 weeks and continued until 16.6 weeks' gestation. Within this interval, HIG was administered between 2 and 6 times. While CMV IgG monitoring showed periodic fluctuations during biweekly HIG administration cycles, high CMV IgG avidity indices remained stable over the whole treatment period. The results were compared with a historic cohort with first trimester CMV infection without treatment that also had an amniocentesis at about 20 weeks.

Results:

Each subject had amniocentesis performed. Maternal-fetal transmission before amniocentesis occurred in only one of the 40 cases (2.5%, [95% CI:0 – 13.2%]). Currently 38 fetuses delivered. At delivery, two additional subjects had late gestation transmission. Thus there was only one case of HIG failure. Considering all three cases with maternal-fetal transmission, the transmission rate was 7.9% of 38 cases, [95% CI: 2.7 – 20.8%]). All infected neonates were asymptomatic at birth. Matched historical controls were 108 pregnancies with 38 transmissions (35.2%, [95% CI: 26.2 – 45.0%]), which was significantly higher than in the HIG administration group.

Conclusion:

After a primary maternal CMV infection in the first trimester, HIG administration prevents maternal-fetal transmission up to 20 weeks of gestation.