Prevalence and correlates of vaginal estrogenization in postmenopausal women in the United States.

Objective: This work aims to establish current population-based vaginal estrogenization norms for postmenopausal US women.

Methods: Using a US national probability sample of 868 postmenopausal women ages 57 to 85 years (mean age 67.6 ± 0.3 y, 21.6 ± 0.5 y since menopause), we calculated the epithelial maturation value (MV) generated from self-collected vaginal specimens and compared findings with historical clinical data. Linear and logistic regressions were used to describe the relationship between vaginal estrogenization and sociodemographic, physical, gynecologic, and sexual characteristics.

Results: Among postmenopausal women, mean MV was 46.6 ± 0.8 (SD 17.4, range 2.5-100) and stable across age groups. In every age group, vaginal estrogenization was higher among postmenopausal nonusers of hormone therapy (HT) in the 2005-2006 US cohort than reported for the 1960s Canadian clinical cohort. MV was also higher among women who used postmenopausal HT in the prior 12 months compared with those who did not (55.1 ± 1.2 vs 44.4 ± 0.9, P < 0.001). In multivariate analyses, HT use, obesity and African American race were each independently associated with higher MV. Overall, MV was not associated with sexual activity, but low MV was associated with vaginal dryness during intercourse among sexually active women.

Conclusions: Compared to 1960s clinical data, current population estimates revealed higher vaginal estrogenization across all age groups and no decline with age. The strongest independent correlates of vaginal estrogenization in postmenopausal US women were current HT use, obesity, and African American race. Postmenopause, half of all women exhibit low vaginal estrogenization.