Valacyclovir cuts mom-to-baby cytomegalovirus transmission

Treatment with oral valacyclovir appears to reduce the rates of vertical transmission of cytomegalovirus (CMV) infection, with a low frequency of side effects, as shown in a study.

For the study, researchers conducted a systematic review and meta-analysis of recent studies wherein oral valacyclovir 8 g/day has been shown to help reduce the vertical CMV transmission rate in pregnant women with primary CMV infection acquired periconceptionally or during the first trimester.

Multiple online databases were searched for relevant randomized controlled trials (RCT) and quasi-randomized studies. The primary outcome of interest was the result of amniocentesis. A one-stage individual patient data meta-analysis was performed by applying a generalized linear mixed model, clustered by the different trials. Then, a subgroup analysis was conducted, with the effect of valacyclovir assessed separately in the periconceptional period and in the first trimester.

A total of three studies met the eligibility criteria and were included in the analysis (n=527 women). Pooled data showed that valacyclovir was associated with lower odds of vertical transmission (adjusted odds ratio [aOR], 0.34, 95 percent confidence interval [CI], 0.18–0.61). This benefit was consistent for periconceptional period (aOR, 0.34, 95 percent CI, 0.12–0.96) and first trimester (aOR, 0.35, 95 percent CI, 0.16–0.76) infections.

In addition, treatment with valacyclovir lowered the chances of neonatal infection (aOR, 0.30, 95 percent CI, 0.19–0.47), both for periconceptional period (aOR, 0.30, 95 percent CI, 0.14–0.61) and in first trimester (aOR, 0.30, 95 percent CI, 0.17–0.54) subgroups.

Finally, valacyclovir was associated with reduced odds of pregnancy termination due to CMV-associated severe foetal findings (aOR, 0.23, 95 percent CI, 0.22–0.24). The gestational age at the initiation of treatment was positively correlated with all outcomes.

In terms of safety, the overall prevalence of severe side effects was 2.1 percent.