Risk factors related to early pregnancy loss in fresh IVF/ICSI: An analysis of 954 embryo transfer cycles

Early pregnancy loss (EPL) is a common complication of assisted reproductive technology treatment; however, the exact factors involved in EPL are not fully understood. This study aimed to evaluate the risk factors for EPL in fresh in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) cycles. This retrospective cohort study was conducted on all couples who underwent clinical pregnancy in fresh IVF/ICSI cycles from January to December 2019 at a single large reproductive medical center. In total, 954 cycles were included in this study. Univariate and multivariate logistic regression analyses were performed to evaluate relevant risk factors for EPL. Curve fitting and threshold analyses were used to explore the association between risk factors and EPL. Compared with women with a normal total antral follicle count (AFC) (>= 10, <15), those with a low AFC (<10) had a higher risk of EPL (odds ratio 2.97, 95% confidence interval: 1.38-6.38, P < .05). Patients with an estradiol/progesterone ratio (E2/P) >= 1.1 had significantly lower odds of EPL than women with E2/P < 1.1 (odds ratio 0.51, 95% confidence interval 0.28-0.91, P < .05). E2/P and serum human chorionic gonadotropin (hCG) levels negatively correlated with EPL. By using a 2-piecewise regression model, the inflection point of serum hCG level was 599.9 IU/L. Our results showed that lower AFC, E2/P, and serum hCG levels were associated with a higher EPL risk in fresh IVF/ICSI cycles.