Objective To investigate the association of human chorionic gonadotropin(HCG) level on day 3 of embryo culture with embryo development. Methods Spent culture media were collected from individually cultured embryos on day 3 of in vitro fertilization and embryo transfer(IVF-ET) cycles. HCG concentration in the culture media was measured using an ELISA kit and its association with embryo development was assessed. Results In the 163 samples of embryo culture media from 60patients, HCG was positive in 153 sample...