• Development and Reproduction
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• v.25 no.4
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• pp.213-223
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• 2021

Controlled ovarian hyperstimulation (COH) is routinely used in the in vitro fertilization and embryo transfer (IVF-ET) cycles to increase the number of retrieved mature oocytes. However, the relationship between repeated COH and ovarian function is still controversial. Therefore, we investigated whether repeated ovarian stimulation affects ovarian aging and function, including follicular development, autophagy, and apoptosis in follicles. Ovarian hyperstimulation in mice was induced by intraperitoneal injection with pregnant mare serum gonadotropin (PMSG) and human chorionic gonadotropin (hCG). Mice subjected to ovarian stimulation once were used as a control group and 10 times as an experimental group. Repeated injections with PMSG and hCG significantly reduced the number of primary follicles compared to a single injection. The number of secondary and antral follicles increased slightly, while the number of corpus luteum increased significantly with repeated injections. On the other hand, repeated injections did not affect apoptosis in follicles associated with follicular atresia. The expression of autophagy-related genes Atg5, Atg12, LC3B, and Beclin1, cell proliferation-related genes mTOR, apoptosis-related genes Fas, and FasL was not significantly different between the two groups. In addition, the expression of the aging-related genes Dnmt1, Dnmt3a, and AMH were also not significantly different. In this study, we demonstrated that repeated ovarian stimulation in mice affects follicular development, but not autophagy, apoptosis, aging in ovary. These results suggest that repetition of COH in the IVF-ET cycle may not result in ovarian aging, such as a decrease in ovarian reserve in adult women.

• Clinical and Experimental Reproductive Medicine
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• v.40 no.1
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• pp.38-41
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• 2013

Liver damage induced by ovarian stimulation has been demonstrated in some cases reported in the literature. However, there has never been a fruitful debate on this topic. The present manuscript tried to fill this gap. We reported a case of a 35-year-old nulliparous woman admitted to our obstetric emergency room for severe pre-eclampsia. She had been subjected to four cycles of controlled ovarian stimulation for intrauterine insemination. At 32 weeks of gestation, she developed severe pre-eclampsia, which led to HELLP syndrome complicated by fatal liver failure. The etiological link between ovarian stimulation and HELLP syndrome is intriguing. Further investigations are needed to understand whether repeated ovarian stimulation may represent a risk factor in pre-eclamptic patients.

• Clinical and Experimental Reproductive Medicine
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• v.38 no.4
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• pp.234-237
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• 2011

Objective: During stimulated IVF cycles, up to 15% of oocytes are recovered as immature. The purpose of this study was to investigate the trend of oocyte maturity in repeated ovarian stimulation for IVF. Methods: One hundred forty-eight patients were selected who underwent two consecutive IVF cycles using same stimulation protocol during 2008 to 2010. Ovarian stimulation was performed with FSH and human menopausal gonadotropin and flexible GnRH antagonist protocol in both cycles. Oocyte maturity was assessed according to presence of germinal vesicle (GV) and the first polar body. Immature oocyte was defined as GV stage or metaphase I oocyte (GV breakdown with no visible polar body) and cultured up to 48 hours. If matured, they were fertilized with ICSI. Results: Percentages of immature oocytes were 30.8% and 32.9% ($p$=0.466) and IVM rates of immature oocytes were 36.2% and 25.7% ($p$=0.077), respectively. A significant correlation was noted between percentage of immature oocytes in the two cycles (R=0.178, $p$=0.03). Women with >40% immaturity in both cycles (n=21) showed lower fertilization rate of $in$ $vivo$ matured oocytes (56.4% vs. 72.0%, $p$=0.005) and lower pregnancy rate (19.0% vs. 27.1%, $p$=0.454) after the second cycle when compared with women with <40% immaturity (n=70). In both groups, female age, number of total retrieved oocyte and embryos transferred were similar. Conclusion: In repeated ovarian stimulation cycles for IVF, the immature oocyte tended to be retrieved repetitively in consecutive IVF cycles.

• Clinical and Experimental Reproductive Medicine
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• v.16 no.2
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• pp.205-210
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• 1989

To investigate the effects of ovarian cysts on the controlled ovarian hyper-stimulation cycles, 16 patients with 16 paired cycles for IVF-ET were analyzed. These patients had taken both type of cycles, i.e., with cyst(cyst group) and without cyst(control group). Mean diameter of ovarian cysts in cyst group was 18.2mm. There were no significant differences in hormone levels in early follicular phase between two groups. No significant differences were found in total dosage of hMG(IU) administered during the ovarian stimulation $843.8{\pm}123.0$ vs $891.0{\pm}129.8$, serum estradiol level (pg/ml) on the day of hCG administration($1542.8{\pm}1100.6$ vs $1567.5{\pm}1193.0$), the number of aspirated follicles $10.0{\pm}3.4$ vs $11.2{\pm}4.3$ and oocytes $5.3{\pm}3.3$ vs $6.2{\pm}3.1$, the fertilization rate(51.2 % vs 57.2 %) and the cleavage rate(40.5 % vs 52.0 %). Serum estradiol terminal patterns during COH in one group tended to be repeated in the other group. In conclusion, this study suggests that small ovarian cysts do not adversely impact on the controlled ovarian hyperstimulation parameters in IVF - ET program and the presence of small ovarian cyst without concomitant high basal serum estradiol level is not an indication of the cancellation of the controlled ovarian hyperstimulation for IVF-ET.

• Clinical and Experimental Reproductive Medicine
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• v.48 no.3
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• pp.198-202
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• 2021

Considerable disagreement exists regarding whether endometrial polyps should be removed before attempting natural pregnancy and before pregnancy via intrauterine insemination (IUI) or in vitro fertilization (IVF). Through a literature review, we obtained information on the impact of endometrial polyps and polypectomy on fertility outcomes. Several observational studies have suggested that women with unexplained infertility may benefit from endometrial polypectomy for a future natural pregnancy. A few studies reported benefits from endometrial polypectomy in infertile women who plan to undergo IUI. However, no strong evidence supports polypectomy as a way to improve the pregnancy rate in infertile women who plan to undergo IVF or polypectomy during controlled ovarian stimulation for IVF. Although no studies have defined criteria for the polyp size that should be removed in infertile women, clinicians should be aware that small endometrial polyps (<10 mm) sometimes regress spontaneously. Endometrial polypectomy is currently justified in patients with repeated IVF failure, but more studies are needed to verify that endometrial polypectomy itself will eventually increase the pregnancy rate. Although several mechanisms by which endometrial polyps exert a negative effect on fertility have emerged, there is no consensus about the proper management of endometrial polyps in infertile women. Therefore, the management of endometrial polyps should be individualized depending on the patient's situation and clinician's preference.

• Clinical and Experimental Reproductive Medicine
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• v.36 no.4
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• pp.275-281
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• 2009

Objective: This study was performed to evaluate the effect of oxytocin antagonist on the outcome of IVF/ICSI cycles in infertile patients with repeated failure of IVF/ICSI treatment. Method: Forty patients who had experienced two or more failures of IVF/ICSI treatment without low ovarian reserve, were recruited for this prospective randomized study. All patients received controlled ovarian stimulation (COS) using GnRH antagonist multidose protocol (MDP). For the intervention group, intravenous administration of atosiban (mixed vasopressin $V_{1A}$/oxytocin antagonist) started with a bolus dose 6.75 mg one hour before embryo transfer (ET) and continued at an infusion rate of 18 mg/hour. After ET, administered atosiban was reduced to 6 mg/hour and continued for 2 hours. The main efficacy endpoints were clinical pregnancy rate and implantation rate. Results: Patients' characteristics were comparable in the intervention and control groups. COS parameters and IVF results were also similar. The number of uterine contractions for 3 minutes measured just before ET was significantly lower in the intervention group than control group ($3.5{\pm}1.4$ vs $8.7{\pm}2.2$, p<0.001). While there was no statistically significant difference in the clinical pregnancy rate between control group and intervention group (20.0% and 40.0%, p=0.168), the implantation rate was significantly higher in the intervention group, with 16.9% (11/65) compared with 6.0% (4/67) in the control group (p=0.047). There were no differences in ectopic pregnancy rate and miscarriage rate between the two groups. Conclusion: This study demonstrates that administration of oxytocin antagonist during ET can improve the implantation rate probably by decreasing the frequency of uterine contractions in infertile patients undergoing IVF/ICSI treatment.