Snapshot A 24-year-old G1P0 woman at 27 weeks gestation presents with painful lesions on her genitals. She denies any fevers, chills, or other flu-like symptoms. She reports that she has had ulcers in that area before that tested positive for HSV-2. She reports being concerned about transmission to her baby. She is started on acyclovir, which is a pregnancy category B medication. Introduction Overview untreated genital herpes (most commonly herpes simplex virus-2) in pregnancy results in an increased risk of neonatal herpes simplex virus (HSV) infection in a primary HSV infection, the transmission rate to the neonate is 50% Epidemiology Incidence 5% of all women of childbearing age have a history of genital herpes 22% of pregnant women are infected with HSV-2 Demographics pregnant women Risk factors women previous genital infection number of sexual partners ETIOLOGY Pathogenesis mechanism HSV is transmitted via direct contact with mucosa or disrupted skin HSV transmission to the neonate occurs with passage of the neonate through the infected vaginal canal Presentation History history of genital ulcers Symptoms common symptoms may be asymptomatic genital ulcers Physical exam inspection tender erosions on external genitalia, vagina, or buttocks Studies Lesional studies viral culture polymerase chain reaction for HSV-1 and HSV-2 Tzanck smear multinucleated epithelial giant cells Differential Varicella zoster virus infection key distinguishing factor rash is often more vesicular, with vesicles on an erythematous base that can become pustular if reactivation of VZV, vesicles will group along a dermatome Treatment Delivery vaginal delivery if there are no active lesions cesarean delivery if there are active lesions, cesarean delivery should be performed within 4-6 hours of membrane rupture Medical acyclovir and valacyclovir indications all patients with active recurrent or primary genital herpes pregnancy category B Complications Erythema multiforme Disseminated HSV infection Neonatal transmission Eczema herpeticum