Early-life exposure to endocrine-disrupting chemicals can alter the development and hormone responsiveness of reproductive tissues. Oxybenzone (benzophenone-3), a widely used ultraviolet filter, exhibits estrogen receptor agonist and antagonist activity and has been shown to disrupt hormone-sensitive tissues following developmental exposure. Using a two-hit model, the effects of perinatal oxybenzone exposure and a prepubertal 17α-ethinyl estradiol (EE2) challenge on mammary gland outcomes in BALB/c mice were evaluated; however, uterine tissues collected under identical conditions have not yet been fully imaged or analyzed.

The current study aims to extend these findings by performing detailed morphological and histological analyses of uterine samples collected from female offspring exposed perinatally to oxybenzone and/or prepubertally to EE2. Uteri obtained at postnatal day 26 were processed for imaging and quantitative assessment of uterotrophic and structural endpoints. By integrating these uterine outcomes with previously reported mammary gland and morphometric data, this work will evaluate whether early-life oxybenzone exposure alters uterine sensitivity to a later estrogenic challenge.

We hypothesize that developmental exposure to oxybenzone will modify uterine morphology and/or responsiveness to EE2, consistent with its endocrine-disrupting properties. These analyses will fill a critical gap in the existing dataset and provide a more comprehensive understanding of how early-life exposure to oxybenzone influences female reproductive tissue development and estrogen responsiveness.