Steroid sex hormone, involved in many regulatory processes, but most prominently in the development of female sex organs, the menstrual cycle, and pregnancy.
Source:
PAC, 2016, 88, 713. 'Glossary of terms used in developmental and reproductive toxicology (IUPAC Recommendations 2016)' on page 751 (https://doi.org/10.1515/pac-2015-1202)