AUTHOR=Fu Longlong , Zhou Fang , Chen Guoping , Yuan Renpei , Li Wenjie , Qiu Shi , Tang Liang , Liu Wenshu , Gu Yiqun , Lu Wenhong TITLE=Morphological Parameters of 29994 sperm in a fertile male population—based on Papanicolaou staining and SSA-II Plus JOURNAL=Frontiers in Endocrinology VOLUME=16 YEAR=2025 URL=https://www.frontiersin.org/journals/endocrinology/articles/10.3389/fendo.2025.1546290 DOI=10.3389/fendo.2025.1546290 ISSN=1664-2392