Abstract:Objective To investigate the value of single serum human chorionic gonadotropin (β-HCG) level on day 7 and 14 after in vitro fertilization and frozen-thawed embryo transfer cycle (IVF-FET) in prediction of pregnant outcomes. Methods A retrospective analysis was performed on 255 pregnant patients, who were transferred with frozen-thawed embryos in the Reproductive Center of the Affiliated Hospital, Shandong University of Traditional Chinese Medicine between January 2016 and January 2017. According to the outcomes of pregnancy they were divided into a normal pregnancy group (including a single continued pregnancy subgroup and a twins continued pregnancy subgroup), and an abnormal pregnancy group (including an ectopic pregnancy subgroup and a single non-viable pregnancy subgroup). The level of serum β-HCG was analyzed on the 7th and 14th days after transplantation (abbreviated as HCG7d, HCG14d), and the results were analyzed. Results The HCG7d and HCG14d of the normal pregnancy group were higher than those of the abnormal pregnancy group (P < 0.05). There was no significant difference in HCG7d between the single non-viable pregnancy subgroup and the single continued pregnancy subgroup (P > 0.05). The HCG14d of the single nonviable pregnancy subgroup was lower than that of the single continued pregnancy subgroup (P < 0.05). Conclusions The quantitative determination of serum β-HCG on days 7 and 14 after FET might be of some value in prediction of early pregnant outcomes, and the serum β-HCG on day 14 has higher predictive value.