Abstract
Objective
To compare the number of oocytes retrieved and clinical outcomes of ovulation induction in an older population treated with in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) (IVF/ICSI) using different rFSH options and the effectiveness of antagonist treatment to induce ovulation using gonadotropin-releasing hormone agonists (GnRH-a) in combination with an human chorionic gonadotropin (HCG) trigger.
Methods
A total of 132 fresh cycles were selected for this study, which were treated with IVF/ICSI in our hospital from March 2022 to December 2022. Observations were made according to different subgroups and the effects of different triggering methods on the number of oocytes obtained, embryo quality, and clinical outcomes.
Results
The initial gonadotropin (Gn) dose, the number of oocytes, and the number of MII oocytes were higher in group A than in group B (p < .05), and the clinical pregnancy rate was 29.41% in group A. Group B had a clinical pregnancy rate of 27.5%. The double-trigger group was superior to the HCG-trigger group in terms of the number of 2PN, the number of viable embryos, and the number of high-quality embryos (p < .05). The use of a double-trigger regimen (OR = 0.667, 95%CI (0.375, 1.706), p = .024) was a protective factor for the clinical pregnancy rate, whereas AFC (OR = 0.925, 95%CI (0.867, 0.986), p = .017) was an independent factor for the clinical pregnancy rate.
Conclusions
The use of a dual-trigger regimen of GnRH-a in combination with HCG using an appropriate antagonist improves pregnancy outcomes in fresh embryo transfer cycles in older patients.
Introduction
Currently, infertility in the elderly population has become an important issue of global concern [Citation1]. Assisted reproductive technology (ART) plays a crucial role in solving fertility problems, especially in the advanced age group [Citation2]. In vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) are commonly used assisted reproductive technologies that have revolutionized the field of reproductive medicine [Citation3]. In recent years, the gonadotropin-releasing endocrine antagonist (GnRH-ant) regimen has become one of the most commonly used controlled ovulation regimens for assisted reproduction therapy [Citation4]. GnRH is secreted by the hypothalamus and binds to its pituitary gonadotropin receptor (GnRHR) to stimulate the secretion and synthesis of Gns, follicle-stimulating hormone (FSH), and luteinizing hormone (LH) [Citation5].
However, advanced maternal age poses a challenge to the success rate of IVF/ICSI treatment due to declining oocyte quality and quantity [Citation6]. Several strategies have been explored to improve the chances of successful pregnancy in advanced maternal age, including controlled ovarian hyperstimulation (COH) with recombinant follicle stimulating hormone (rFSH) [Citation7]. rFSH promotes, however, advanced maternal age poses a challenge to the success rate of IVF/ICSI treatment due to declining oocyte quality and quantity [Citation6]. Several strategies have been explored to improve the chances of successful pregnancy in advanced maternal age, including COH with rFSH [Citation7]. rFSH promotes the development of multiple follicles and improves oocyte quality, thereby increasing the likelihood of successful fertilization and embryo implantation [Citation8]. In the context of COH, it is critical to evaluate the clinical efficacy and outcomes of different rFSH regimens in older women undergoing IVF/ICSI treatment [Citation9–12].
To date, there is a lack of clear consensus on the optimal rFSH options for this population. Therefore, a comprehensive analysis of clinical data is needed to identify more effective rFSH regimens to improve outcomes in older women. In addition, the use of gonadotropin-releasing hormone agonists (GnRH-a) in combination with human chorionic gonadotropin (HCG) triggers during COH has shown promise in elderly patients [Citation13–16]. This combination is thought to improve the quality of the oocytes retrieved, thus potentially leading to better outcomes in terms of fresh embryo transfer and subsequent pregnancy rates [Citation17].
Therefore, the main objective of this study was to compare the number of oocytes retrieved and clinical outcomes in older women treated with IVF/ICSI using different rFSH during COH. In addition, we wanted to investigate the efficacy of GnRH-a combined with HCG triggering regimens in elderly patients in order to provide better triggering strategies for neo-embryo transfer cycles and to better guide clinical practice.
Patients and methods
General information
Selected patients who underwent IVF/ICSI between March 2022 and December 2022 at our institution. Inclusion criteria [Citation1]: (1) age ≥35 years old, (2) first cycle of fresh IVF/ICSI, and (3) superovulation with antagonist regimen and transfer of 1–2 embryos. Exclusion criteria [Citation13]: (1) no available embryos; (2) patients with submucous fibroids, endometriosis, infertility uterine malformations, or other genital tumors; (3) previous history of ovarian surgery; (4) suffering from other endocrine diseases. A total of 132 fresh cycles were finally included in the study. The study was approved by the Hebei Cangzhou Hospital of Integrated Traditional Chinese Medicine and Western Medicine. Written informed consent was obtained from all individuals included in this study.
Grouping
According to the different rFSH, they were divided into the following two groups: group A, the domestic rFSH group (N = 66). Domestic rFSH choose Jin Sai Heng. Jin Sai Heng is similar to Gonal-f, also is a kind of recombinant human follicle stimulating hormone, is a kind of white sparsely body, is suitable for the female does not ovulate or ovulation obstacle, the main role is used for ovulation, promote the development of follicles. Jin Sai Heng belongs to the domestic ovulation drugs, the price is usually in the 200–300 yuan, although compared with the imported ovulation drugs to be cheaper, this drug is to promote the growth of follicles, slower, will not be crazy, it is the effect and quality of the drug is very good, and the drug on the woman’s ovary stimulation is relatively mild. And group B, the imported rFSH (N = 66). At the same time, subgroup analysis was conducted on HCG day with different trigger modes (HCG trigger and double trigger) to observe the effects of different trigger modes on the number of eggs obtained, embryo quality, and clinical outcomes.
Methods
The patient’s physical examination indicators were normal before assisted conception, the endocrine level was normal basal state in 2–4 d of menstrual cycle, and ultrasound detected the follicle diameter basal state, according to the patient’s AFC, AMH, and BMI, the patient started Gn treatment in 2–4 d of menstrual cycle, and was given either domestically produced recombinant follicle-stimulating hormone (r-FSH, Jin Sai Heng, ChangChun GeneScience Pharmaceuticals Co. Ltd., Changchun, China) or imported r-FSH (Gonal-f, Merck Serono, Darmstadt, Germany) treatment for 4–5 d. After 5 d, the detection of follicle diameter was started. The follicle diameter was detected after 4–5 d. When the follicle diameter ≥14 mm was detected, antagonist was added to HCG day, when the dominant follicle diameter reached 18 mm (trigger timing: the best time to trigger is when the diameter of the dominant follicle on ultrasound is ≥18 mm), HCG or GnRH-a combined with HCG trigger was injected in the evening, and eggs were retrieved by puncture under the vaginal ultrasound guidance after 36–38 h. HCG trigger: HCG (chorionic villus stimulating hormone for injection, Guangdong Lizhu Pharmaceutical Group, Lizhu Pharmaceutical Factory, Zhujiang, China) 2000–12,000 IU intramuscularly; GnRH-a combined with GnRH-a, and eggs were retrieved by puncture under the vaginal ultrasound guidance after 36–38 h. 12,000 IU intramuscular injection; GnRH-a combined with HCG double trigger: GnRH-a (treprostinil acetate injection, 0.1 mg/branch, Gensci, Changchun, China; or treprostinil acetate injection, 0.1 mg/branch, Pfizer, Freiburg, Germany; or treprostinil acetate injection, 0.1 mg/branch, Beaufort-Ipsen, Paris, France) 0.2 mg combined with 2000–12,000 IU HCG intramuscular injection. IVF/ICSI fertilization will be performed according to the egg acquisition situation on the day of egg collection. Embryo culture and evaluation were carried out according to the routine operation of our reproduction center, and fresh and high-quality embryos were routinely selected on the 3rd day after egg collection or blastocysts were transferred on the 5th day.
Observation indicators
(1) General characteristics of the patients in each group: age (years), number of cycles, infertility (years), BMI (kg/m2), AMH, basal FSH, basal E2, basal LH, basal PRL, basal P, basal T, and antral follicle count (AFC).
(2) Ovulation parameters and indices of each group of patients: number of transfer cycles, AMH value, Gn use time, average Gn dose, total Gn use, average starting Gn dose, endothelial thickness on the day of transfer, number of follicles greater than 12 mm on the day of HCG, number of follicles greater than 18 mm on the day of HCG, number of oocytes retrieved, number of MII oocytes, number of 2PNs, number of transferable embryos, number of high quality embryos, number of embryos transferred per cycle, and number of embryos transferred per cycle. Number of embryos transferred per cycle.
(3) Assisted reproduction outcome indicators for each patient group: HCG positive rate, canceled cycle transfer rate, and clinical pregnancy rate. The formula for defining each indicator is as follows.
HCG positive rate: number of HCG positive / number of fresh cycle transfers * 100%.
Canceled cycle transfer rate: Canceled fresh cycle transfer/number of cases * 100%.
Clinical pregnancy rate: number of clinical pregnancies/number of fresh cycle transfers*100%.
Statistical analysis
All values are expressed as mean ± standard deviation (SD). One-way ANOVA was performed using SPSS 25.0 software (SSPS Inc., Chicago, IL) software. Independent samples t-test was used for comparison between groups; count data were expressed as rate (%). Clinical pregnancy outcome influencing factors were analyzed by logistic regression analysis. Differences were considered significant at p < .05.
Results
Characteristics of the study population
The final number of 132 operated patients analyzed is shown in . All patients included in the study were comparable (p > .05), including age, number of cycles, years of infertility, BMI, FSH, AMH, and AFC. Detailed results are shown in .
Table 1. The basic characteristics of the study population.
Comparison of ovulation promotion process and outcome for different types of FSH
Gn utilization
There was a statistically significant difference in Gn initiation dose between the two groups (Jin Sai Heng group > Gonal-f group, p < .05), whereas there was no statistically significant difference in the number of Gn days and total Gn dose (p > .05). The detailed results are shown in .
Table 2. Comparison of Gn use for ovulation promotion in patients in group AB.
Ovulation promotion results
The number of oocytes obtained and the number of M II oocytes in group A were higher than those in group B (p < .05); the number of follicles with a diameter >18 mm on the day of HCG, the number of follicles with a diameter ≥12 mm on the day of HCG and the thickness of the endothelial lining on the day of HCG in the two groups did not show any significant difference (p > .05) ().
Table 3. Comparison of ovulation promotion outcomes in patients.
Fertilization and embryo culture
There was no statistical difference in the number of 2PN, the number of transferable embryos, and the number of good quality embryos between the two groups (p > .05). The detailed results are shown in .
Table 4. Comparison of indicators related to fertilization and embryo culture of patients.
Embryo transfer and pregnancy
The number of fresh cycle transfers and the post-transfer HCG positivity rate in the two groups. Fifty-one cases of fresh cycle transfers in group A Jin Sai Heng (n = 66), one case of no transferable embryos obtained, 15 cases of canceled fresh cycle transfers with a canceled fresh cycle transfer rate of 22.73%; 18 cases of post-transfer HCG positivity with a HCG positivity rate of 35.29%; 15 cases of clinical pregnancy with a clinical pregnancy rate of 29.41%.
In group B, there were 40 cases of Gonal-f (n = 66) fresh cycle transfers, four cases did not obtain transferable embryos, 22 cases of fresh cycle transfers were canceled, and the rate of canceling fresh cycle transfers was 55%; there were 21 cases of post-transfer HCG positivity, and the rate of HCG positivity was 52%; and there were 11 cases of clinical pregnancies, and the rate of clinical pregnancies was 27.5%. Detailed results are shown in .
Table 5. Patient fresh cycle pregnancy outcomes.
Logistic regression analysis of the factors affecting clinical pregnancy rates by different types of FSH
After correcting for factors related to age, AFC, BMI, and years of infertility, logistic regression analyzed that Jin Sai Heng affects the increase in clinical pregnancy rate; in addition, age, AFC, BMI, and years of infertility had no significant effect. The detailed results are shown in .
Table 6. Logistic regression analysis of factors influencing clinical pregnancy rates.
HCG trigger vs. double trigger comparison results
The number of 2PN, the number of MII eggs, and the number of high-quality embryos in the double-trigger group were better than those in the HCG trigger group (p < .05), but from the analysis of the basic conditions of the two groups of patients, there were statistically significant differences in the number of cycles experienced by the HCG trigger group compared with that of the double trigger group, the basal FSH value was higher than that of the double trigger group, and the number of AFCs was less than that of the double trigger group (p < .05); thus, it could not be ruled out that the patients in the HCG trigger group had ovarian function, the effect of poorer ovarian function on the outcome of the promoted embryos. The detailed results are shown in .
Table 7. Comparison of HCG trigger and double trigger.
Logistic regression analysis of the factors influencing the HCG trigger and double trigger on clinical pregnancy rates
After correcting for confounders related to age, AFC, BMI, and years of infertility, logistic regression analysis showed that the use of the double-trigger regimen (OR = 0.667, 95%CI (0.375, 1.706), p = .024) was a protective factor for clinical pregnancy rate, and AFC (OR = 0.925, 95%CI (0.867, 0.986), p = .017) was an independent factor for clinical pregnancy rate. The detailed results are shown in .
Table 8. Logistic regression analysis of factors influencing clinical pregnancy rates.
Discussion
Infertile patients of advanced age cause ovarian hyporesponsiveness due to a decrease in the number of ovarian AFCs [Citation13]. Therefore, ways to improve the quality of the oocytes as well as obtaining more available embryos have become a hot topic of research in treating patients. The ultimate goal of ART is to achieve a healthy clinical pregnancy [Citation13]. In studies comparing the efficacy of different pharmacological treatments, it is important to take into account the possibility of unquantifiable biases and confounders from the patient’s own influence (e.g. age, years of infertility, sperm quality, and endometrial thickness) or from post-oocyte collection procedures (e.g. fertilization, embryo culture, etc.) [Citation18,Citation19]. Therefore, when considering that the purpose of ovarian stimulation with rFSH preparations is essential to produce multiple oocytes to facilitate IVF/ICSI, the production of multiple oocytes is critical to the success of the IVF/ICSI process [Citation20]. This increases the chances of obtaining high quality embryos and improves clinical pregnancy rates. Each oocyte can unite with a sperm to form an embryo, and then the embryo with the most developmental potential is transferred back into the uterus to achieve a pregnancy [Citation21–23]. Therefore, our primary outcome measure is the number of oocytes retrieved. Studies have shown that clinical pregnancy rates correlate with the number of oocytes obtained, as well as in the absence of ovarian hyperstimulation syndrome (OHSS), the optimal number of oocytes maximally taken ranges from 10 to 15 [Citation24].
In the present study, the results of ovulation promotion using r-FSH preparations of domestic rFSH (Jin Sai Heng) or imported rFSH (Gonal-f) showed that the number of oocytes and the number of MII oocytes obtained by the patients using Jin Sai Heng was significantly higher than that obtained by the patients using Gonal-f, and that the Jin Sai Heng group had more oocytes than the Gonal-f group, and the number of oocytes obtained was in the optimal range of the good prognosis for IVF. The number of oocytes obtained was within the range of the optimal number of oocytes for good IVF prognosis. There was no significant difference in clinical pregnancy rates between the two groups. Age is an important factor affecting the quantity and quality of oocytes and an independent influence on clinical pregnancy rate [Citation25]. However, age was not an independent influencing factor in this study due to the small sample size, there was no statistically significant difference.
For patients at high risk of OHSS, the drug of choice is GnRH-a [Citation26]. However, but the GnRH-a trigger can lead to defective luteal function, which affects pregnancy outcomes in fresh cycle transplant patients [Citation27,Citation28]. In recent years, the GnRH-a combined HCG trigger has been increasingly promoted, and the double trigger can both stimulate endogenous LH peak and FSH elevation with GnRH-a to promote oocyte maturation, and take advantage of the extra-long half-life of HCG to maximize the maintenance of LH concentration in the luteal phase, thus preventing luteal function from being compromised [Citation29]. Studies have shown that GnRH-a combined with HCG double-triggered individuals have a high rate of live births in fresh-cycle transfers, as well as an increased rate of oocyte and mature oocyte acquisition, total blastocysts, and the number of high-quality embryos [Citation30]. The results of this study showed that the number of 2PN, the number of transferable embryos, and the number of high-quality embryos in the double-trigger group were better than those in the HCG trigger group (p < .05), but analyzing the basic conditions of the patients in the two groups, there was a statistically significant difference between the HCG trigger group, which had experienced more cycles, had a higher basal FSH value and had a lower number of AFCs than the double trigger group (p < .05). Thus, it could not be excluded that the HCG trigger the effect of poorer ovarian function of patients in the group on the outcome of promoted embryos. The mean age of the patients in this study was greater than 35 years old and the sample size was small, thus affecting the results of this study indicating that the HCG positivity and clinical pregnancy rates in double trigger fresh embryo transfer cycles were not significantly different from the HCG single trigger results. After correcting for confounders related to age, AFC, BMI, and years of infertility, logistic regression analysis showed that the use of double-trigger regimen (OR = 0.667, 95%CI (0.375, 1.706), p = .024) a protective factor for the clinical pregnancy rate, and the AFC (OR = 0.925, 95%CI (0.867, 0.986), p = .017) was an independent factor for clinical pregnancy rate. Antral follicle count is an important indicator for assessing ovarian reserve and potential number of eggs, and a higher AFC usually implies an abundant ovarian reserve and can predict the potential production of more mature follicles during controlled ovulation [Citation31]. The combined standard-dose HCG trigger in the double-trigger regimen mimics the LH peak to compensate for this deficiency, so the dual action of the double-trigger regimen in terms of the LH peak contributes to oocyte maturation and improves oocyte and embryo quality [Citation32].
However, the increasing prevalence of infertility problems in the general population, and thus the growing demand for ART, and consequently the growing skepticism among couples of childbearing age about the safety of this method of ART [Citation33,Citation34]. Therefore, the real impact of ART on the health of unborn babies needs to be analyzed. With the development of artificial intelligence, it has been progressively applied in all aspects of medicine. Knowledge is combined with computer science through machine learning algorithms. AI has the potential to improve infertility diagnosis and ART outcomes estimated in terms of pregnancy and/or live birth rates, especially in cases of repeated ART failure. Applications of AI can be used to determine optimal embryo morphodynamic parameters, to determine the cost-effectiveness of human oocyte cryopreservation, to predict IVF and ICSI outcomes, and to classify spermatocytes [Citation35].
Conclusions
In summary, in the antagonist regimen ovulation cycle for patients in the advanced age population, more oocytes were retrieved in the Jin Sai Heng group than in the Gonal-f group, and the number of oocytes obtained was in the range of the optimal number of oocytes for good IVF prognosis, and the GnRH-a combined HCG trigger regimen could significantly increase the number of 2PNs, the number of transferable embryos, and the number of high-quality embryos compared with the HCG trigger regimen alone. Therefore, in clinical practice, the appropriate dual-trigger regimen of rFSH and GnRH-a combined with HCG can be selected according to the patient’s condition in the advanced age group. However, since this paper is a retrospective study and the sample size is small, the experimental results need to be confirmed by randomized controlled studies with larger sample sizes.
Author contributions
JXM is responsible for the guarantor of integrity of the entire study, study concepts and design, definition of intellectual content, clinical studies, data acquisition, manuscript preparation and review; MNW is responsible for the guarantor of integrity of the entire study, study concepts and design, experimental studies, data analysis, statistical analysis, manuscript preparation and review; QQZ is responsible for the guarantor of integrity of the entire study, study concepts and design, literature research, clinical studies, data acquisition, statistical analysis, manuscript editing and review; HM is responsible for the guarantor of integrity of the entire study, definition of intellectual content, literature research, data acquisition and analysis, manuscript editing; SQW is responsible for the guarantor of integrity of the entire study, study concepts, definition of intellectual content, literature research, clinical studies, data analysis, statistical analysis, manuscript preparation and editing. All authors read and approved the final manuscript.
Ethical approval
The study was approved by the Hebei Cangzhou Hospital of Integrated Traditional Chinese Medicine and Western Medicine.
Consent form
Written informed consent was obtained from all individuals included in this study.
Disclosure statement
No potential conflict of interest was reported by the author(s).
Data availability statement
All data generated or analyzed during this study are included in this. Further enquiries can be directed to the corresponding author.
Additional information
Funding
References
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