Objective:To explore the clinical effect and cost-effectiveness of a delayed start protocol with gonadotropin-releasing hormone (GnRH) antagonist in patients with diminished ovarian reserve (DOR).Methods:A retrospective study was performed in 376 cycles of DOR patients undergoing in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) from July 2017 to December 2019 in Reproductive Center of Yichun Maternal and Child Health Hospital who had GnRH antagonist protocol to ovarian stimulation. According to the start time, those patients were divided into two groups, the delayed start group including 43 cycles (the start time at day 7-10 of menstruation), the conventional start group including 333 cycles (start normally at day 2-4 of menstruation). The ovulation induction results, clinical outcomes and cost-effectiveness ratio of the two groups with controlled ovarian sitmulation (COS) were compared. Propensity score matching (PSM) was performed on age, duration of infertility, body mass index, follicle-stimulating hormone (FSH) level on the first day of gonadotropin (Gn) used, the dosage of Gn used on the first day, antral follicle count (AFC), anti-Müllerian hormone (AMH) were analyzed again after PSM to reduce the influence of unequal characters between the two groups. Results:Before matching, the conventional start protocol patients' FSH level of the first day of Gn used was lower than that of the delayed start protocol, the results of ovarian stimulation such as the total duration of Gn used [(8.0±2.0) d], the total dosage of Gn used [(1 740.1±561.2) IU], estradiol level on human chorionic hormone (hCG) injection day [(1 371.2±1 203.3) ng/L], total number of oocytes retrieved (5.1±5.1), number of M II oocytes retrieved (4.4±4.3) were lower [(9.0±2.0) d, P<0.001; (2 055.1±634.7) IU, P<0.001; (1 853.5±1 351.5) ng/L, P=0.03; 7.0±5.5, P=0.03; 6.1±4.8, P=0.03], but the two pronuclei fertilization rate (71.7%±32.1%) was higher than that in the conventional start protocol patients (58.9%±31.2%, P=0.01). We also found the total costs of per cycle [(14 179.9±2 909.4) yuan] was less than that of the conventional protocol [(16 003.6±2 543.1) yuan, P<0.001]. After matching, the two groups had the same estradiol level on hCG injection day, total number of oocytes retrieved, number of M II oocytes retrieved ( P>0.05), but the total duration of Gn used [(7.9±2.0) d], the total dosage of Gn used [(1 729.8±563.8) IU], the total cost per cycle [(14 232.5±2 923.9) yuan] of delayed protocol remain lower and the two pronuclei fertilization rate (71.0%±32.2%) was also higher than those of the conventional protocol [(8.8±1.5) d, P=0.03; (2 021.5±726.1) IU, P=0.04; (15 590.2±3 116.9) yuan, P=0.04; 55.4%±37.5%, P=0.04]. There was no difference in the fresh embryo transfer rate, the cycle cancellation rate and the clinical pregnancy rate between the two groups neither before nor after PSM. Conclusion:The delayed start antagonist protocol maybe improve the normal fertilization rate and reduce the total days of Gn used, the total dosage of Gn used so as to have less total cost of each cycle in patients with DOR.

Objective:To explore the clinical effect and cost-effectiveness of a delayed start protocol with gonadotropin-releasing hormone (GnRH) antagonist in patients with diminished ovarian reserve (DOR).Methods:A retrospective study was performed in 376 cycles of DOR patients undergoing in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) from July 2017 to December 2019 in Reproductive Center of Yichun Maternal and Child Health Hospital who had GnRH antagonist protocol to ovarian stimulation. According to the start time, those patients were divided into two groups, the delayed start group including 43 cycles (the start time at day 7-10 of menstruation), the conventional start group including 333 cycles (start normally at day 2-4 of menstruation). The ovulation induction results, clinical outcomes and cost-effectiveness ratio of the two groups with controlled ovarian sitmulation (COS) were compared. Propensity score matching (PSM) was performed on age, duration of infertility, body mass index, follicle-stimulating hormone (FSH) level on the first day of gonadotropin (Gn) used, the dosage of Gn used on the first day, antral follicle count (AFC), anti-Müllerian hormone (AMH) were analyzed again after PSM to reduce the influence of unequal characters between the two groups. Results:Before matching, the conventional start protocol patients' FSH level of the first day of Gn used was lower than that of the delayed start protocol, the results of ovarian stimulation such as the total duration of Gn used [(8.0±2.0) d], the total dosage of Gn used [(1 740.1±561.2) IU], estradiol level on human chorionic hormone (hCG) injection day [(1 371.2±1 203.3) ng/L], total number of oocytes retrieved (5.1±5.1), number of M II oocytes retrieved (4.4±4.3) were lower [(9.0±2.0) d, P<0.001; (2 055.1±634.7) IU, P<0.001; (1 853.5±1 351.5) ng/L, P=0.03; 7.0±5.5, P=0.03; 6.1±4.8, P=0.03], but the two pronuclei fertilization rate (71.7%±32.1%) was higher than that in the conventional start protocol patients (58.9%±31.2%, P=0.01). We also found the total costs of per cycle [(14 179.9±2 909.4) yuan] was less than that of the conventional protocol [(16 003.6±2 543.1) yuan, P<0.001]. After matching, the two groups had the same estradiol level on hCG injection day, total number of oocytes retrieved, number of M II oocytes retrieved ( P>0.05), but the total duration of Gn used [(7.9±2.0) d], the total dosage of Gn used [(1 729.8±563.8) IU], the total cost per cycle [(14 232.5±2 923.9) yuan] of delayed protocol remain lower and the two pronuclei fertilization rate (71.0%±32.2%) was also higher than those of the conventional protocol [(8.8±1.5) d, P=0.03; (2 021.5±726.1) IU, P=0.04; (15 590.2±3 116.9) yuan, P=0.04; 55.4%±37.5%, P=0.04]. There was no difference in the fresh embryo transfer rate, the cycle cancellation rate and the clinical pregnancy rate between the two groups neither before nor after PSM. Conclusion:The delayed start antagonist protocol maybe improve the normal fertilization rate and reduce the total days of Gn used, the total dosage of Gn used so as to have less total cost of each cycle in patients with DOR.