Background Despite a large number of studies on the selection of trigger drugs, it remains unclear whether the dual trigger with human chorionic gonadotropin (hCG) and gonadotropin-releasing hormone (GnRH) agonist, compared to the trigger with hCG alone, can improve the reproductive outcome of patients undergoing assisted reproductive technology. Therefore, this study aimed to compare the laboratory and clinical outcomes of dual trigger versus single trigger. Methods In this retrospective cohort study, we evaluated 520 in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) cycles between July 2014 and September 2020 at the Reproductive and Genetic Center of Integrative Medicine, The Affiliated Hospital of Shandong University of Traditional Chinese Medicine. All patients underwent IVF/ICSI treatment with fresh embryo transfer using the GnRH antagonist protocol. We used propensity score matching to control for confounding variables and binary logistic regression analysis to determine the correlations between trigger methods and pregnancy outcomes. After propensity score matching, 57 cycles from each group were evaluated and compared for laboratory or clinical outcomes in this retrospective cohort study. Results There was no significant difference in the number of oocytes retrieved, embryos available, top-quality embryos, or the rate of normal fertilization between the dual-trigger and single-trigger protocols, respectively. The incidence of ovarian hyperstimulation syndrome, implantation rate, biochemical pregnancy rate, clinical pregnancy rate, ectopic pregnancy rate, early miscarriage rate, and live birth rate were also similar between the two groups, while the miscarriage rate (37.0% vs. 12.5%, p = 0.045) was higher in the dual-trigger than the single-trigger group. Subsequent binary logistic regression analysis showed that age was a remarkably significant independent predictor of both clinical pregnancy rate (odds ratio = 0.90, 95% confidence interval: 0.84–0.97, p = 0.006) and live birth rate (odds ratio = 0.89, 95% confidence interval: 0.82–0.97, p = 0.005). Conclusions Therefore, dual-trigger for final oocyte maturation might increase miscarriage rate, but in terms of the laboratory and other pregnancy outcomes such as clinical pregnancy rate, early miscarriage rate or live birth rate, there was no evidence to show that dual trigger was superior to an hCG-trigger alone for patients undergoing GnRH-antagonist cycles with fresh embryo transfer. Trial registration Retrospectively registered.

Introduction The relationships between the outcome of frozen-thaw embryo transfer (FET) cycle and endometrial compaction were not quite consistent. Objective To analyze the relationship between the outcome of FET cycle and endometrial compaction. Materials and methods A total of 1420 women using FET were researched. The change in endometrial thickness on ET day and those on the day of progesterone (P) administration start is the basis for grouping. Group 1 was endometrial compaction group, and group 2 was the endometrial non-compaction group. Outcome measure was clinical pregnancy, estradiol (E2) levels, progesterone (P) levels, endometrial morphology, and thickness in each period of FET cycle. Results A significantly lower clinical pregnancy rate was observed in group 2 in comparison with group 1 (43.4% vs. 55.1%, P < 0.01). In addition, P levels on the day of P administration start were lower in group 2 (0.73 ± 0.93 ng/ml vs. 0.90 ± 1.85 ng/ml, P = 0.006), while E2 levels on ET day were higher in group 2 (316.42 ± 304.95 pg/ml vs. 257.88 ± 219.15 pg/ml, P = 0.001) than in group 1. The binary logistic regression analysis showed a lower rate of clinical pregnancy in group 2 (aOR = 0.617, 95% CI 0.488-0.779, P = 0.001). Conclusions Clinical pregnancy rates were significantly higher in women with endometrial compaction on ET day compared to women with no changes or thickening. Therefore, we recommend paying closer attention to endometrial compaction in women undergoing FET as a method to estimate endometrial receptivity.