biostudies-literatureUnknown87(8)Behringer VDeutsches PrimatenzentrumThe project was funded by the Deutsche Forschungsgemeinschaft DFG (German Research Foundation SCHU 1554/6-1, OS 201/6-2, BE 5511/4-1). Further support was provided by the University of Göttingen, Germany and the German Primate Center, Leibniz Institute for Primate Research.In mammals, estrogens and progestogens are crucial for gestation, fetal development, and maternal preparation for parturition and lactation. Measuring these hormones allows for the diagnosis of pregnancy, estimation of pregnancy failures, and potentially prenatal sex determination. We evaluated urinary estrogen and progestogen metabolites as biomarkers for gestation detection and for their utility for fetal sex determination in wild Assamese macaques (Macaca assamensis) using 586 samples from 19 females, including 19 successful pregnancies. Four enzyme-immunoassays were tested for suitability in measuring urinary sex steroids using serial dilution: three assays targeting progestogen and one targeting estrogen metabolites (estrone conjugates, E1C). We performed a biological validation by meAmerican journal of primatologye70065https://www.ebi.ac.uk/biostudies/studies/S-EPMC12367238biostudies-literatureAssessing Gestation and Fetal Sex in Wild Assamese Macaques Using Urinary Estrogen Analysis.PMC12367238Malaivijitnond SMeesawat SBehringer VOstner JSonnweber RHeistermann MSchulke OfalseAssessing Gestation and Fetal Sex in Wild Assamese Macaques Using Urinary Estrogen Analysis.In mammals, estrogens and progestogens are crucial for gestation, fetal development, and maternal preparation for parturition and lactation. Measuring these hormones allows for the diagnosis of pregnancy, estimation of pregnancy failures, and potentially prenatal sex determination. We evaluated urinary estrogen and progestogen metabolites as biomarkers for gestation detection and for their utility for fetal sex determination in wild Assamese macaques (Macaca assamensis) using 586 samples from 19 females, including 19 successful pregnancies. Four enzyme-immunoassays were tested for suitability in measuring urinary sex steroids using serial dilution: three assays targeting progestogen and one targeting estrogen metabolites (estrone conjugates, E1C). We performed a biological validation by me2025-01-01T00:00:00Z2025 Aug2026-05-07T00:18:14.723Z2026-04-07T22:20:12.383ZS-EPMC123672384083423710.1002/ajp.70065