HSV, HIV, and Pregnancy: Epidemiology, Viral Interactions, Management, and Prevention

We summarize the epidemiology, biology, management and prevention of HSV-2 and HIV in pregnancy. The seroprevalence of HSV-2 is higher in people living with HIV than in HIV-negative people, and 75% of women with recurrent genital herpes may have a recurrence during pregnancy. Those with a history of recurrent genital HSV infection should be offered acyclovir/valacyclovir at 36 weeks gestation to decrease need for C-section. The most important intervention for reducing HIV vertical transmission is maternal antiretroviral therapy (ART) to suppress HIV replication. Maternal ART also reduces HSV-2 cervicovaginal shedding and thus, HSV-2 vertical transmission. HSV-2 viral shedding is incompletely suppressed with acyclovir/valacyclovir, and newer drugs such as the helicase-primase inhibitors show promise but have not been studied in pregnancy. Safe options also exist for preventing HIV acquisition in pregnancy but remain in development for HSV-2. Safe, effective HSV-2/HIV management strategies exist in pregnancy. Epidemiology: HSV-2 seroprevalence is higher among women living with HIV compared to women living without HIV, and HIV seroprevalence is higher among individuals living with HSV-2 infection. Vertical HSV-2 transmission: Genital herpes in pregnancy can cause neonatal herpes which has serious potential neonatal morbidity and mortality. Risk factors for vertical transmission include: primary maternal episode of genital herpes, maternal fever during labour, premature or prolonged rupture of membranes, HSV-1 (rather than HSV-2) infection, use of fetal scalp electrodes or instrumentation, and vaginal (rather than Caesarian) delivery. Acyclovir and valacyclovir are safe in pregnancy. Women at 32-36 weeks gestational age with recurrent genital herpes should be offered antivirals to reduce the risk of symptomatic herpes and need for C-section. Vertical HIV transmission: Antiretroviral therapy (ART) of a pregnant person living with HIV is highly efficacious at reducing vertical transmission. Achieving HIV viral suppression as early as possible is critical. Other strategies for reducing vertical transmission include administration of intravenous zidovudine if HIV viral load of the pregnant person is unknown or detectable (though practice varies by country), and/or scheduled C-section at 38 weeks gestational age for pregnant individuals not on optimal ART. Impact of HSV-2 on HIV: HSV-2 infection is associated with an increased risk of HIV acquisition and transmission, although this is not reversed by anti-HSV therapy. Maternal HSV-2 infection may be associated with increased vertical HIV transmission. Impact of HIV on HSV-2: HIV increases HSV-2 reactivations, shedding, and severity of HSV disease. Maternal ART for HIV can reduce the odds of HSV-2 shedding and thus may reduce vertical HSV-2 transmission. Prevention of horizontal HIV transmission: A variety of regimens can be safely used as pre- and post-exposure prophylaxis (PrEP and PEP) in pregnant individuals to reduce the risk of HIV acquisition. Prevention of horizontal HSV-2 transmission: Acyclovir or valacyclovir can be used in people living with HSV-2 to prevent transmission to HSV-seronegative sexual partners, but this has not been studied in persons living with both HSV and HIV.