Conservative management of high-grade squamous intraepithelial lesions (HSILs) seems safe and justified in young women (\<30 years), but evidence is insufficient on whether it is also advisable for older women. This study will be conducted to analyze spontaneous HSIL regression rates in women of reproductive age and establish whether conservative HSIL management could be safely recommended to women of childbearing potential, irrespective of age. This is a single-center prospective observational study that will include consecutive women of reproductive age, referred to a tertiary hospital due to HSIL between March 2021 and December 2025, who prefer conservative management rather than immediate cervical conization. All patients will be followed-up regularly with colposcopy, cytology, human papillomavirus (HPV) testing and biopsies. In case their lesions progress or HSIL persists after 24 months of follow-up, conization will be indicated. Rates of spontaneous regression or resolution, as well as progression rates, will be assessed. Furthermore, the association between potential predictive factors and HSIL resolution will be analyzed.