The Herpes Simplex Virus (HSV), including both Type 1 and Type 2, is a common infection requiring careful management during pregnancy. The primary concern when HSV is present is preventing transmission to the newborn, known as neonatal herpes, which can have serious consequences. A safe and healthy pregnancy is highly achievable through proactive communication with your healthcare provider and adherence to established medical protocols.
Conception Planning and Partner Status
Preparing for conception involves understanding the HSV status of both partners. A type-specific serological blood test detects Immunoglobulin G (IgG) antibodies for HSV-1 and HSV-2, establishing prior exposure. This testing is especially important if one partner is negative, as a primary infection acquired during pregnancy carries the highest risk of neonatal transmission.
If a pregnant individual is seronegative but their partner is positive, the goal is to prevent the acquisition of HSV during pregnancy. Transmission risk reduction involves avoiding sexual contact, including oral sex, during any active outbreaks the partner may experience. Consistent condom use significantly reduces the risk of transmission.
The risk of neonatal herpes is highest when a pregnant individual acquires a primary HSV infection late in the third trimester. At this stage, the body has not had enough time to produce protective antibodies, which normally cross the placenta to safeguard the fetus. Knowing the status of both partners allows for targeted counseling and preventative measures, especially concerning sexual activity in the final months of pregnancy. For established infections before pregnancy, the risk of transmission to the baby is substantially lower, often less than 3% during delivery.
Antiviral Therapy Protocols During Pregnancy
Antiviral medications play a significant role in managing HSV throughout pregnancy to minimize the chances of a maternal outbreak near delivery. The two most commonly used medications are acyclovir and its prodrug, valacyclovir, which have demonstrated favorable safety profiles for the developing fetus. Registry data indicates that exposure to these drugs does not appear to increase the risk of major birth defects compared to the general population risk.
Treatment for HSV is generally divided into episodic therapy and suppressive therapy. Episodic treatment involves taking a short course of medication, typically 5 to 10 days, when an active outbreak occurs to shorten its duration and severity. Suppressive therapy involves taking a lower dose of the antiviral medication daily for a prolonged period.
For individuals with a history of recurrent genital herpes, suppressive therapy is typically initiated at 36 weeks of gestation and continued until delivery. Common regimens include acyclovir 400 milligrams three times a day or valacyclovir 500 milligrams twice a day. The purpose of this late-term suppression is to reduce the frequency of recurrent outbreaks and decrease asymptomatic viral shedding, lowering the risk of active lesions being present at the time of birth.
Should a primary, first-time HSV infection occur during pregnancy, immediate treatment with antivirals is recommended, regardless of the gestational age. If this primary infection occurs near the time of delivery, the high risk of transmission (up to 57%) necessitates a highly aggressive management approach. In such high-risk cases, the antiviral treatment is often continued suppressively until the baby is born.
Minimizing Transmission Risk During Labor and Delivery
The vast majority of neonatal HSV infections, approximately 85%, occur when the newborn comes into direct contact with the virus in the birth canal during passage. Therefore, the goal during labor and delivery is to prevent the baby’s exposure to active lesions or viral shedding. The decision between a vaginal delivery and a Cesarean delivery is based on a careful physical examination at the onset of labor.
If there are no active genital lesions or any prodromal symptoms, such as vulvar pain or tingling, a vaginal delivery is generally considered safe. The suppressive therapy taken in the final weeks of pregnancy significantly increases the likelihood of having a lesion-free delivery. However, if any active lesions are present or if the individual experiences prodromal symptoms, a Cesarean delivery is recommended to bypass the infected birth canal and prevent contact transmission.
Even without active lesions, obstetric procedures that may cause breaks in the infant’s skin, such as the use of a fetal scalp electrode for monitoring, should be avoided if possible. Following birth, close monitoring of the newborn is paramount, especially if the mother had active lesions or a first-time infection near delivery. Although rare, if neonatal herpes is suspected, the infant will require immediate, high-dose intravenous acyclovir treatment to prevent severe morbidity or mortality.