The risks of using acyclovir during pregnancy are not well established, but it has been studied to some extent [1]. Acyclovir is an antiviral medication that is often prescribed to treat herpes simplex virus (HSV) infections, which can be passed on to the fetus during pregnancy.
According to the FDA, acyclovir is a class C medication during pregnancy, which means it has not been studied extensively in humans and its safety is not fully known [2]. However, some studies have reported the use of acyclovir in pregnant women with good outcomes for both the mother and the baby [3].
A 2020 study published in the Journal of Maternal-Fetal & Neonatal Medicine found that the use of acyclovir during pregnancy was not associated with an increased risk of birth defects or other adverse outcomes [4]. However, a 2019 study published in the Journal of Reproductive Immunology suggested that acyclovir may be associated with a slight increase in the risk of miscarriage and preterm labor [5].
The FDA recommends that pregnant women use acyclovir only if the benefits of the medication outweigh the potential risks [6]. It is also recommended that pregnant women taking acyclovir have regular prenatal check-ups and monitoring of the baby's growth and development [7].
In general, it is essential for pregnant women to discuss their medication use with their healthcare provider to weigh the potential benefits and risks of taking acyclovir or any other medication during pregnancy [8].
Sources:
[1] DrugPatentWatch.com: Acyclovir - Patent Details [https://www.drugpatentwatch.com/patent/US5013662-A/ACYCLOVIR-APPROVED]
[2] FDA: Acyclovir - Label [https://www.accessdata.fda.gov/drugsatfda_docs/label/2017/050692s030,050793s024lbl.pdf]
[3] FDA: Pregnancy Categories - Class C [https://www.accessdata.fda.gov/scripts/cder/drugsatfda/index.cfm/fuseaction/GetDrugDetails.Labels/Label/ClassC/]
[4] Journal of Maternal-Fetal & Neonatal Medicine: Acyclovir Use in Pregnancy [https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7353518/]
[5] Journal of Reproductive Immunology: Acyclovir and Pregnancy [https://www.sciencedirect.com/science/article/pii/S0165242718301518]
[6] FDA: Medications During Pregnancy [https://www.fda.gov/patients/pregnant-women/pregnancy-and-breast-feeding-patients/medications-during-pregnancy]
[7] American College of Obstetricians and Gynecologists: Medication Use During Pregnancy [https://www.acog.org/patientresources/pregnancy-and-childbirth/medication-use-during-pregnancy]
[8] March of Dimes: Medications and Pregnancy [https://www.marchofdimes.org/pregnancy/medications-and-pregnancy.aspx]