by Nicole Evans M.D.

Created on: August 15, 2009

Approximately 22% of pregnant women are carrying Herpes Simplex Virus type 2 (HSV-2), the virus that causes genital herpes. Almost 90% of these pregnant women are undiagnosed.

Of women who are unaffected prior to becoming pregnant, 2% will become infected during their pregnancy. However, even with a new infection, approximately 70% of are asymptomatic or simply not recognized as a herpes infection by the pregnant woman.

The identification of pregnant women who are carriers of the Herpes Simplex Virus type 2 (HSV-2) is an important concern. Certainly, this STD can cause the mother distressing symptoms. But the real concern is for the child she is carrying. Infants who are born to women who have ever had genital herpes are at risk of developing neonatal herpes, a potentially lethal condition.

Pregnant women will require treatment with the antivirals acyclovir or valacyclovir for various reasons. These reasons fall into 2 categories. The first is to provide symptomatic relief to the mother. The second category is to prevent neonatal herpes infection.

Antiviral use for maternal genital herpes symptoms:

1. Those pregnant women who are experiencing a symptomatic genital herpes infection may opt to be treated with a one time course of acyclovir or valacyclovir.

2. A pregnant woman who has a history of severe recurrent genital herpes may opt to go on continuous suppressive anti-viral therapy with acyclovir or valacyclovir.

Antiviral use for the prevention of neonatal herpes:

1. A pregnant woman may have a known third trimester acquisition of genital herpes, in other words, she became infected with herpes for the very first time during the third trimester. In this case, most experts recommend a C-section, whether or not she has signs of infection at the time of labor.

An alternate option is to put the mother on suppressive therapy with acyclovir or valacyclovir. Then type-specific antibodies (which cross the placenta to provide protection to the infant) are checked by the time of delivery.

- If Positive for HSV-2 antibodies a vaginal delivery is possible

- If Negative for HSV-2 antibodies a C-section is required

This alternative option is riskier. The suppressive therapy with acyclovir or valacyclovir may not eliminate viral shedding in the birth canal. Additionally, though antibodies may be present, they may not provide sufficient passive immunity for the infant if the antibody quantities are low.

2. A pregnant woman who has symptomatic genital herpes at 36 weeks gestational age or has a history of recurrent symptomatic HSV will be put on antiviral suppressive medication at 36 weeks until the baby is delivered.

Learn more about this author, Nicole Evans M.D..
Click here to send this author comments or questions.