An analysis of data from Denmark showed no associated increased risk of childhood malformations in mothers who were exposed to antiviral drugs such as acyclovir, valaciclovir, and famciclovir during the first trimester of pregnancy, often used in the treatment of herpes simplex and herpes zoster infections – Science Daily reports.
The percentage of herpes simple infections is high, and more than 1 percent. susceptible women acquire the herpes virus during the first trimester of pregnancy, and antiviral treatment is indicated for many women with this condition. Although the safety of aciclovir, valaciclovir and famciclovir is generally well established, data on the use of these drugs in early pregnancy are limited, the authors of the study say, MD. Bjorn Pasternak and Anders Hviid, PhD in medicine from the Statens Serum Institut, Copenhagen, Denmark.
They conducted research on the basis of recorded data to establish associations between the use of aciclovir, valaciclovir, famciclovir in the first trimester of pregnancy and major malformations of the babies born. The study involved 837.795 newborns in Denmark from January 1996 to September 2008. The participating children were not diagnosed with chromosomal abnormalities and genetic disorders, known perinatal defect syndromes or congenital viral infection. National registries were used to confirm information on individually dispensed antivirals, diagnoses of malformations, and potential confounders to analysis.
Of 1804 pregnancies exposed to aciclovir, valaciclovir, or famciclovir during any first trimester period, 40 newborns (2,2%) were diagnosed with severe malformations, compared to 19.920 of 835.991 (2,4%). born of pregnancies not exposed to these drugs. With a few cases aside, exposure to aciclovir, valaciclovir, or famciclovir during the first trimester of pregnancy was not associated with an increased risk of major malformations. First trimester use of aciclovir, the most commonly prescribed antiviral drug, was not associated with serious malformations. These were 32 cases among 1561 drug exposures (2% comparable to 2,4% no exposure). Also, valaciclovir (7 out of 229 newborns – 3,1%) and famciclovir (1 out of 26 newborns – 3,8%) do not show any relationship with serious developmental defects, although the use of the latter drug is infrequent.
Additional analyzes showed no association between antiviral drug exposures and 13 malformative subgroups, although the number of exposures in each subgroup was small, our research increased our understanding that we did not find significant associations between first trimester exposure to drugs affecting herpesviruses and serious developmental defects. Consequently, this has immediate clinical implications and can support safety decisions when prescribing antiviral drugs for herpes virus infection in early pregnancy. Aciclovir is the most widely documented antiviral drug and may be the drug of choice in early pregnancy when data on valaciclovir and famciclovir are insufficient. Future research on antiviral drugs affecting herpesviruses and maternal and child health should include safety studies covering miscarriage, prematurity and breastfeeding, the authors conclude. (PAP)