Affiliation: Gillings School of Global Public Health, Department of Epidemiology
For decades, it has been hypothesized that reproductive tract infections (RTIs) are risk factors for uterine fibroids. However, only two recent studies have been conducted. We aimed to investigate the relationship between RTIs and fibroids in a large study using ultrasound screening for fibroids. We used cross-sectional enrollment data from African-American women ages 23-34 years with no previous fibroid diagnosis. For Aim 1, RTI history was measured by self-report. For Aim 2 we used serology, an immunological measure of past exposure with a focus on herpes simplex virus type 2 (HSV-2) because prior published data have suggested a possible association, and serology for HSV-2 is much more accurate than self-report. For both aims, fibroid status was measured by standardized ultrasound. Secondary fibroid outcomes were size, number, and total volume. Age- and multivariable-adjusted logistic regression were used to estimate odds ratios (ORs). In total, 1,656 women were included; 22% had fibroids. Self-reported bacterial vaginosis (BV) was associated with a 21% increased odds of fibroids [aOR 1.21, 95% confidence interval (CI) 0.93-1.58]. Self-reported chlamydia infection and pelvic inflammatory disease were associated with a 38% (aOR 0.62, 95% CI 0.40-0.97) and a 46% (aOR 0.54, 95% CI 0.25-1.17) reduced odds of having two or more fibroids, respectively. Those with a previous self-reported BV diagnosis had a 47% increased odds of having 2 or more fibroids (aOR 1.47, 95% CI 0.98-2.21) and a 41% increased odds of having a larger total fibroid volume (aOR 1.41, 95% CI 0.98-2.04). There was no significant association between HSV-2 seropositivity and fibroid presence (multivariable-adjusted OR: 0.94 95% CI: 0.73, 1.20); nor were there any associations with size of largest fibroid, number of fibroids, or total fibroid volume. Our study was the first to investigate the association of fibroids with HSV-2 exposure assessed serologically. In addition, it was the first to explore the relationship between self-reported RTIs and fibroid size, number, and total volume. There appeared to be no strong associations between self-reported RTIs or serologically-measured HSV-2 seropositivity and the presence of fibroids.