BACKGROUND: Diminished ovarian reserve (DOR) is one of the obstacles affecting the reproductive outcomes of patients receiving assisted reproductive therapy. The purpose of this study was to investigate whether dual trigger, including gonadotropin-releasing hormone agonist (GnRHa) and human chorionic gonadotropin (hCG), can improve pregnancy outcomes in patients with DOR undergoing in vitro fertilization (IVF) cycles using mild stimulation protocols.
METHODS: A total of 734 patients with DOR were included in this retrospective study. Patients were divided into a recombinant hCG trigger group and a dual trigger group (hCG combined with GnRHa) according to the different trigger drugs used. The main outcome measures included the number of oocytes retrieved, the fertilization rate, the number of transferable embryos, the implantation rate, the clinical pregnancy rate, the miscarriage rate, the live birth rate (LBR), and the cumulative live birth rate (CLBR). Generalized linear model and logistic regression analyses were performed for confounding factors.
RESULTS: There were 337 cycles with a single hCG trigger and 397 cycles with dual trigger. The dual trigger group demonstrated significantly higher numbers of retrieved oocytes [3.60 vs. 2.39, adjusted β = 0.538 (0.221-0.855)], fertilized oocytes [2.55 vs. 1.94, adjusted β = 0.277 (0.031-0.523)] and transferable embryos [1.22 vs. 0.95, adjusted β = 0.162 (-0.005-0.329)] than did the hCG trigger group, whereas no significant difference in the fertilization rate was observed between the two groups. Moreover, the embryo transfer cancellation rate (35.5% vs. 43.9%) was obviously lower in the dual trigger group. Among the fresh embryo transfer cycles, the implantation rate, clinical pregnancy rate, miscarriage rate and live birth rate were similar between the two groups. After controlling for potential confounding variables, the trigger method was identified as an independent factor affecting the number of oocytes retrieved but had no significant impact on the CLBR.
CONCLUSIONS: Dual triggering of final oocyte maturation with hCG combined with GnRHa can significantly increase the number of oocytes retrieved in patients with DOR but has no improvement effect on the implantation rate, clinical pregnancy rate or LBR of fresh cycles or on the CLBR.

OBJECTIVE: To determine whether a reduced dose of follicle-stimulating hormone (FSH) before human chorionic gonadotropin (hCG) trigger during ovarian stimulation can affect in vitro fertilization (IVF) outcomes.
METHODS: This study included 347 patients with a normal ovarian response who received a reduced dose of FSH before hCG trigger for 2-3 days (Group A) and 671 patients who did not receive a reduced dose (Group B) from a university-affiliated IVF center between January 2021 and December 2022. The primary endpoint was estrogen (E2) and progesterone (P) levels on the day of hCG trigger, fresh embryo transfer cycles, laboratory outcomes, and clinical outcomes between the two groups.
RESULTS: On the day of hCG trigger, Group A had significantly lower E2 and P levels than those in Group B (3454.95 ± 1708.14 pg/mL versus 3798.70 ± 1774.26 pg/mL, p = 0.003; and 1.23 ± 0.53 ng/mL versus 1.37 ± 0.59 ng/mL, p < 0.001, respectively). The proportion of patients with P levels ≥ 1.5 ng/mL was 22.48% in Group A compared to 34.58% in Group B (p < 0.001), while the proportion of patients with E2 ≥ 5000 pg/mL was 15.27% in Group A compared to 25.93% in Group B (p < 0.001). The fresh embryo-transfer cycle rate in Group A was higher than that in group B (54.47% and 32.64%, respectively; p < 0.001). Despite the reduction in FSH dosage, there were no significant differences between groups regarding the number of oocytes retrieved, total number of mature oocytes, normal fertilization rate, cleavage rate, Day 3 top-quality rate, implantation rate, pregnancy rate per cycle, and early pregnancy loss rate.
CONCLUSIONS: While a reduced dose of FSH prior to hCG trigger during ovarian stimulation did not significantly affect IVF outcomes, it was associated with lower E2 and P levels, resulting in fewer cycles with E2 ≥ 5000 pg/mL and P ≥ 1.5 ng/mL on the day of the hCG trigger.

Is there any difference in clinical outcomes between a human chorionic gonadotrophin (HCG)-only trigger and a dual trigger combining gonadotrophin-releasing hormone agonist (GnRHa) and HCG in a progestin-primed ovarian stimulation (PPOS) protocol?
This retrospective cohort study included women younger than 40 years old with a normal ovarian reserve who underwent IVF/intracytoplasmic sperm injection treatment with a PPOS protocol. Participants were allocated to two groups according to the triggering medicines. The clinical outcomes were compared, with cumulative live birth rate (CLBR) being the primary outcome.
In total, 1066 women were included, 565 in the HCG-only group and 501 in the dual trigger group. Demographic parameters were comparable between the groups. Fewer oocytes were retrieved in the HCG-only trigger group (dual trigger 12.56 ± 7.12 versus HCG-only trigger 11.62 ± 6.02, P = 0.020). No significant difference was observed in the numbers of two-pronuclear embryos (7.12 ± 4.90 versus 6.76 ± 4.45, P = 0.208) and high-quality embryos (4.01 ± 3.70 versus 3.96 ± 3.32, P = 0.815). The CLBR after one complete cycle was also similar (40.72% versus 43.72%, P = 0.354). Multivariate logistic analysis confirmed that the trigger method had no association with CLBR (odds ratio [OR] 0.763, 95% confidence interval [CI] 0.578-1.005, P = 0.055) in the PPOS-treated patients.
Compared with the HCG-only trigger group, comparable embryological and clinical outcomes were achieved, although more oocytes were retrieved in the dual trigger group. This suggests that there may be no extra benefit from dual triggering, and that it should not be recommended for routine use in the general population undergoing PPOS protocols.

OBJECTIVE: Does dual trigger (the co-administration of triptorelin 0.2 mg and recombinant human chorionic gonadotrophin (HCG) [Decapeptyl 0.2 mg + Ovitrelle 250 µg]) versus standard recombinant HCG (Ovitrelle 250 µg) affect embryo quality and morphokinetic parameters?
METHODS: Morphokinetic parameters and embryo quality of embryos derived from the first gonadotrophin-releasing hormone (GnRH) antagonist IVF/intracytoplasmic sperm injection (ICSI) cycles triggered by dual trigger or standard HCG trigger in women ≤42 years. Outcome measures included time to pronucleus fading (tPNf), cleavage timings (t2-t8), synchrony of the second cycle (s2), duration of the second cycle (cc2) and known implantation data (KID) scoring for embryo quality. Multivariate linear and logistic regression analyses were performed for confounding factors.
RESULTS: A total of 4859 embryos were analysed: 1803 embryos from 267 cycles in the dual trigger group and 3056 embryos from 463 cycles in the HCG trigger group. The groups were similar in patient and treatment characteristics apart from a higher maternal body mass index and lower maturation rate in the dual trigger group. Time to second polar body extrusion was shorter in the dual trigger group. Cleavage timings from zygote to an 8-cell embryo did not differ between the two groups. There was a higher percentage of embryos with an optimal cc2 duration in the HCG group. In multivariate logistic regression models, the trigger type was not a significant factor for cell cycle division parameters.
CONCLUSIONS: Overall, there was no significant difference in the morphokinetic parameters or quality of embryos evaluated using a time-lapse monitoring system between embryos derived following dual trigger compared with HCG.