ASYMPTOMATIC MATERNAL SHEDDING OF HERPES-SIMPLEX VIRUS AT THE ONSET OF LABOR - RELATIONSHIP TO PRETERM LABOR

Objective: To determine if fetal growth restriction and prematurity ar e observed with subclinical shedding of herpes simplex virus (HSV) at the onset of labor. Methods: Within 48 hours of delivery, cultures wer e taken from the cervix and external genitalia of 15,923 asymptomatic pregnant women without symptoms or signs of genital HSV infection; res ults were positive for HSV in 57. Each of these 57 women were compared with a control group composed of the three culture-negative women del ivering immediately before and the three delivering immediately after each woman shedding HSV. Results: The median birth weight for infants born to the 57 women with asymptomatic shedding was 3050 g, compared w ith 3360 g among the 342 women without asymptomatic shedding, a statis tically significant difference (P < .002). These differences were due to very low birth weight (LBW) among the five infants of women with su bclinical viral shedding secondary to recently acquired primary genita l herpes; these five infants had a median gestational age of 33 weeks, compared with 37 weeks for the 14 infants of mothers with nonprimary, first-episode disease and 39 weeks for the 33 infants of women with r eactivation disease, also a significant difference (P = .018). Conclus ions: Asymptomatic genital shedding of HSV at the onset of labor becau se of subclinical primary genital HSV infection is associated with pre term delivery. Women who acquire genital HSV-2 before pregnancy and ar e shedding subclinically at the onset of labor experience no increase in adverse outcome. Thus, prevention of the prematurity and LBW associ ated with genital herpes means that acquisition of the infection in la te pregnancy must be prevented.