Risk factors for herpes simplex virus transmission to pregnant women: a couples study

This study was undertaken to determine risk factors for herpes simplex virus (HSV) acquisition among at risk pregnant women.

Women in a prospective study of HSV acquisition in pregnancy invited their sexual partners for HSV type-specific serologic testing. Risk factors for HSV susceptibility, exposure, and acquisition were examined.

A total of 3192 couples enrolled; 22% included women at risk for HSV-1 or HSV-2. Among 582 HSV-1 seronegative women with HSV-1 seropositive partners, 14 (3.5% adjusted for gestation length) acquired HSV-1. Having a partner with a history of oral herpes was associated with HSV-1 acquisition (odds ratio [OR] 8.1, 95% CI: 1.8-36.0) and accounted for 75% of incident infections. Among 125 HSV-2 seronegative women with HSV-2 seropositive partners, 17 (20% adjusted for gestation length) acquired HSV-2. Duration of partnership of 1 year or less was associated with HSV-2 acquisition (OR 7.8, 95% CI: 2.3-25.7) and accounted for 63% of incident infections. No combination of clinical characteristics could identify the majority of susceptible women with serologically discordant partners.

HSV acquisition rates in pregnancy are high in discordant couples, especially for HSV-2. Interventions that address risk factors for HSV acquisition should be studied in pregnancy. Clinical profiles cannot replace serologic screening to identify susceptible women with serologically discordant partners.