Guidelines on Herpes in Pregnancy

In June of last year, the Society of Obstetricians and Gynaecologists of Canada (SOCG) published new guidelines [PDF] on the management of herpes simplex virus (HSV) in pregnancy.

There are two types of herpes simplex virus, HSV-1 and HSV-2. HSV-1 tends to be the cause of oral herpes (“cold sores” or “fever blisters”) and HSV-2 tends to be the cause of genital herpes, although either virus can affect the oral or genital areas. Herpes in pregnancy is of concern because of the potential to pass the virus to the fetus during or near delivery, especially when the woman is newly infected late in pregnancy.

SOGC’s guidelines recommend that women’s history of genital herpes be evaluated early in pregnancy, and that women with a history of genital herpes outbreaks be counselled about the risk of transmission at delivery. Suppressive therapy is suggested at or after 36 weeks gestation for women with recurrent herpes. They also recommend that “At delivery, women with recurrent HSV should be offered a Caesarean section if there are prodromal symptoms or in the presence of a lesion suggestive of HSV.”

In plain language, they suggest offering a c-section if the woman has an active herpes sore or symptoms suggesting one is about to appear. They explain that the risk of transmission at delivery is highest when a woman has a new outbreak in the third trimester, and that women should be counselled about the risk and offered a c-section.

The authors also note that there is likely little benefit to c-section if delivery is imminent, or with “prolonged rupture of membranes.” They recommend avoidance of scalp electrodes and fetal scalp sampling, and suggest that use of intrauterine monitoring devices be considered carefully.

Guidelines on the same topic from the American College of Obstetricians and Gynecologists, published in 2007, reach similar conclusions that c-section “is indicated in women with active genital lesions or prodromal symptoms,” but that c-section is “not recommended for women with a history of HSV infection but no active genital disease during labor.”

Neither guideline suggests that c-section is necessary for all HSV-infected women or even all women with outbreaks of the virus at delivery. For additional discussion of genital herpes in pregnancy, see this resource from the March of Dimes.