Routine herpes screening in pregnancy pays off.(GUEST EDITORIAL)

It is cost effective and good clinical care to screen all pregnant women with a type-specific antibody test for herpes.

Although the American College of Obstetricians and Gynecologists does not currently recommend it, I have found that screening is essential to properly managing pregnancy and limiting the risk of neonatal infection.

I'm certainly not the first person to come up with this idea. Dr. Zane A. Brown, an ob.gyn. in Seattle, for example, has made this case eloquently in the literature. But routine screening is a practice that I use in my clinic and one that still too few physicians are employing.

Let's look at a fairly typical case. A 36-week pregnant woman came to my office complaining of vaginal discharge. Upon examination, I found type 2 herpes lesions all over her cervix. I performed a type-specific antibody test for herpes simplex virus type 2 (HSV-2) to determine if it was an old or new infection. The test was negative, indicating that the infection was new and that she had not developed antibodies that could protect the fetus.

About 22% of all women in a discordant relationship--in which the man has herpes and the woman does not--will acquire herpes by the end of their pregnancy. If a woman catches herpes late in the third trimester, the risk of the baby being born with neonatal herpes is about 50% (and about 30% if she has antibodies to herpes simplex virus type 1 [HSV-1] from a previous infection). Children born with herpes face a 60% chance of dying or having a severe neurologic syndrome like blindness, seizures, or psychomotor retardation.

In the United States, there are about 2,000 cases a year of neonatal herpes, most of which are transmitted during labor. About 70% of these cases are attributed to HSV-2 and 30% to HSV-1. The greatest risk of transmission occurs with a primary infection acquired late in the third trimester.

The woman who presented at my clinic was treated with a week of valacyclovir 1 g b.i.d., then continued on valacyclovir 500 mg b.i.d. until a cesarean section was performed. However, had this woman been screened earlier in her pregnancy, before she contracted herpes, her antibody test would have been negative; then we would have asked her partner to be screened, and his test would have been positive. The couple then could have been counseled on how to prevent her from catching the infection.