Is Vaginal Birth Safe for Women With Genital Herpes?

It can be stressful to know that you have to think about genital herpes during pregnancy. It's possible for there to be severe consequences if a child becomes infected with the herpes virus during labor or shortly after being born. In rare cases, neonatal herpes can even be deadly. Because of this, women with genital herpes are often counseled toward a very conservative management of their pregnancy and delivery options.

Despite this, conservative management may not be necessary in all circumstances. Not all pregnant women with genital herpes are at equal risk of transmitting the virus to their infant. The risk of neonatal herpes is highest, by far, for women who become infected with herpes during their pregnancy. That's particularly true if they become infected near the end of their pregnancy.

Transmission rates from mother to infant are substantially lower for women who have been infected for a long period of time. That's true even if they have an active infection during the course of their pregnancy. There is also some data that women with genital HSV-1 infections may have a greater risk of giving their infants neonatal herpes than women with HSV-2.

Doctors generally recommend suppressive therapy for all pregnant women with HSV infections. This should be started at 36 weeks of pregnancy. A C-section is also recommended if they have an active genital herpes outbreak near their time of delivery.

The suppressive therapy is to reduce the risk of an outbreak and lower viral shedding. The C-section is performed in order to reduce the chance that the infant will be exposed to the virus while passing through the birth canal.

Neonatal herpes is a scary prospect. Many pregnant women are understandably torn about their pregnancy management options. That's particularly true if they are interested in having a more natural childbirth experience.

In addition, some women worry about infecting their child even with suppressive therapy. After all, the herpes virus can be present in the body even when there is not currently an outbreak. Therefore, they may not feel comfortable giving birth vaginally even if they haven't had an outbreak in years.

Doctors can certainly test for viral DNA during pregnancy. Still, there is some question about how useful these tests are, particularly when they're done more than a few days before birth. A 1999 study of herpes viral shedding during pregnancy found that almost 60 percent of women who gave birth within two days of having a positive test were still positive during delivery. However, testing any earlier than that was largely inaccurate at predicting herpes shedding at the time of birth.

A large 2005 study found that neonatal herpes was extraordinarily rare in women who were not culture positive at the time of delivery. Five percent of women who were culture positive for HSV gave birth to infants with neonatal herpes. Only 0.02 percent of women who were culture negative did. 

It would be ideal if there were more large studies examining this question. Still, it seems likely that detectable virus levels at the time of delivery is linked to neonatal herpes infection. Or, more accurately, it seems clear that not having detectable virus levels during delivery makes transmitting neonatal herpes highly unlikely.

A large 2011 study, published in JAMA, investigated how often people with asymptomatic herpes infections shed the virus and how much virus they shed. The researchers found that people with asymptomatic genital HSV-2 shed detectable levels of virus 10 percent of the time. That's about half as often as people with symptomatic infections. However, the amount of virus they shed was similar.