Herpes Simplex Virus Type 2 Seroprevalence and Incidence and Growth of Ultrasound-Diagnosed Uterine Fibroids in a Large Population of Young African-American Women.

Reproductive tract infections have long been hypothesized to be risk factors for development of uterine fibroids, but few studies have investigated the issue. In our 2016 cross-sectional analysis from the Study of Environment, Lifestyle and Fibroids (2010-2018), a large Detroit, Michigan, community-based cohort study of 23- to 35-year-old African-American women with ultrasound fibroid screening, we found no association between a very prevalent reproductive tract infection, herpes simplex virus type 2 (HSV-2), and fibroids. With prospective data from the cohort (ultrasounds performed every 20 months over 5 years), we examined HSV-2's associations with fibroid incidence (among 1,208 women who were fibroid-free at baseline) and growth (among women with fibroids at baseline or diagnosed during the study). Using Cox proportional hazards models, we computed adjusted hazard ratios and 95% confidence intervals for fibroid incidence comparing HSV-2-seropositive women with HSV-2-seronegative women. The influence of HSV-2 infection on growth was assessed on the basis of the difference in fibroid size between successive ultrasounds (1,323 growth measures) using a linear mixed model, estimating the percent difference in growth scaled to 18 months. HSV-2 seropositivity was not associated with fibroid incidence (adjusted hazard ratio = 0.88, 95% confidence interval: 0.69, 1.12) or growth (estimated growth difference = 3.1%, 95% confidence interval: -5.8, 13.0). Women can be reassured that HSV-2 infection is unlikely to increase their risk of fibroid-related health problems, given these longitudinal measures.