Epicatechin promotes oocyte quality in mice during repeated superovulation.

The negative impacts of repeated superovulation on mitochondrial function and oocyte quality remain unresolved. Epicatechin (EC), a polyphenolic compound found in the human diet with strong antioxidant activity, was investigated for its effects and underlying mechanism on embryonic development after repeated superovulation. The results showed that as the number of superovulation cycles increased, the number of 2-cell embryos decreased, the development of embryos in subsequent in vitro culture was delayed, the apoptosis rate of blastocyst cells increased and the number of blastocyst cells decreased. However, intraperitoneal injection of EC (10 mg/kg body-weight) for two consecutive days during repeated superovulation increased mitochondrial DNA copies in 2-cell embryos of mice. It also promoted the expression of antioxidant enzyme genes in ovaries, increased the content of glutathione (GSH) content and improved the antioxidant capacity of ovaries. Altogether, these results revealed that intraperitoneal injection of EC could increase the embryonic mitochondrial DNA copy number (mtDNA-CN) and enhance the ovary's antioxidant capacity and GSH content, ultimately promoting the quality of mouse embryos in the process of repeated superovulation.

Repeated Superovulation Accelerates Primordial Follicle Activation and Atresia.

For humans, ARTs (assisted reproductive technologies) have become the most effective method to treat subfertility/infertility in clinic. To obtain enough oocytes during ART, ovarian stimulation is performed by exogenous hormones, and some patients undergo several ovarian stimulation cycles. Although some adverse effects of ARTs on women and offspring are reported, few studies are focused on the effects of multiple superovulation on ovarian reserve. In the present study, we found that repeated superovulation significantly reduced primordial follicle number and the serum AMH. Compared to the decreased antral follicle number, the expression of genes related to primordial follicle activation, such as Foxo3, Akt, and Rptor, and the atretic follicle number in ovaries were increased by superovulation times. We further found that repeated superovulation reduced the plasma level of FSH, LH, and estradiol, and increased the expression of genes related to apoptosis (Bax, Casp3 (caspase-3), Casp8, and Casp9) in granulosa cells, providing evidence that repeated superovulation disrupted the balance between survival and death in granulosa cells. In summary, our results suggest that repeated superovulation has adverse effects on folliculogenesis.

Melatonin alleviates the deterioration of oocytes from mice subjected to repeated superovulation.

Induction of repeated superovulation with exogenous hormones is widely used in assisted reproductive technology (ART). Though it is generally safe, emerging evidence has indicated that repeated superovulation may compromise oocyte quality. However, few studies have explored how to ameliorate such impairment. Because melatonin has beneficial influences on oocytes in various detrimental environments, we aimed to explore whether melatonin could protect mouse oocytes after repeated superovulation. We found that repeated superovulation markedly reduced meiotic maturation and disrupted spindle organization and chromosome alignment. Furthermore, we observed reduced mitochondrial content and enhanced early apoptosis in oocytes from mice subjected to repeated superovulation. In addition, 5-methylcytosine (5mc) fluorescence intensity was lower in oocytes from experimental mice than in those from control mice, indicating that repeated superovulation disrupts genomic DNA methylation, and elevations in reactive oxygen species levels indicated that repeated superovulation also induces oxidative stress. Conversely, melatonin administration improved oocyte maturation and attenuated the observed defects. Interestingly, supplementation with melatonin during in vitro maturation had the same protective effects on oocytes as in vivo melatonin administration. In summary, our results show that melatonin can improve oocyte quality after repeated superovulation and thus provide a potential strategy to improve ART efficiency.

Repeated superovulation increases the risk of osteoporosis and cardiovascular diseases by accelerating ovarian aging in mice.

Superovulation procedures and assisted reproductive technologies have been widely used to treat couples who have infertility problems. Although generally safe, the superovulation procedures are associated with a series of complications, such as ovarian hyper-stimulation syndrome, thromboembolism, and adnexal torsion. The role of long-term repeated superovulation in ovarian aging and especially in associated disorders such as osteoporosis and cardiovascular diseases is still unclear. In this study, we sought to determine if repeated superovulation by ten cycles of treatment with pregnant mare serum gonadotropin/human chorionic gonadotropin could affect ovarian reserve, ovarian function, bone density and heart function. Ovarian reserve and function were reflected by the size of the primordial follicle pool, anti-Mullerian hormone expressions, hormone levels and fertility status. Furthermore, we examined bone density and heart function by microCT and cardiovascular ultrasonography, respectively. After repeated superovulation, the size of the primordial follicle pool and the expression of anti-mullerian hormone decreased, along with the concentrations of estrogen and progesterone. Mice exposed to repeated superovulation showed an obvious decrease in fertility and fecundity. Furthermore, both bone density and heart ejection fraction significantly decreased. These results suggest that repeated superovulation may increase the risk of osteoporosis and cardiovascular diseases by accelerating ovarian aging.

[Repeated superovulation induction after failure in previous IVF-ET cycles with the ultra-long protocol: Analysis of outcomes of clinical pregnancy].

OBJECTIVE: To analyze the clinical outcomes of repeated superovulation induction in patients with adenomyosis or moderate to severe pelvic endometriosis after failure in previous IVF-ET cycles with the ultra-long protocol. METHODS: We retrospectively analyzed the clinical data about 37 patients with adenomyosis or moderate to severe pelvic endometriosis in our center from 2009 to 2013, who underwent repeated IVF-ET after failure in the previous cycles with the ultra-long protocol, namely by injection of 2－6 ampoules of 3.75 mg gonadotropin-releasing hormone agonist (GnRH-a). All the patients met the following requirements: hCG-negative at 14 days after transfer, within 3－7 days after menstruation, and properly down-regulated serum follicle stimulating hormone (FSH) (<10 mIU/ml), luteinizing hormone (LH) (<10 mIU/ml), estradiol (E2) (<30 pg/ml), follicle diameter (<10 mm) and endometrial thickness, and received GnRH (Gonal-F, Serono) for ovulation induction. We compared the clinical and laboratory data and pregnancy outcomes between the first and repeated cycles before and after ovulation induction. RESULTS: The repeated cycles, as compared with previous ones, showed significant increases in the antral follicle count (AFC) on the first day of stimulation (7.55 ± 1.86 vs 6.45 ± 2.5, P<0.05), number of follicles =≥14 mm in diameter on the hCG trigger day (7.81 ± 3.6 vs 5.56 ± 3.68, P<0.05), level of E2 (ï¼»2 362.15 ± 1 210.49ï¼½ vs ï¼»1 749.22 ± 1 139.44ï¼½ pg/ml, P<0.05), and numbers of oocytes retrieved (7.51 ± 3.23 vs 4.78 ± 3.41, P<0.05) and embryos transferred (2.00 ± 0.33 vs 1.50 ± 0.67, P<0.05), exhibited a remarkably reduction in the dose of GnRH (ï¼»1 791.65 ± 1 889.41ï¼½ vs ï¼»3 439.56 ± 1 836.53ï¼½ IU, P<0.05), and achieved a clinical pregnancy rate of 62.16%. CONCLUSIONS: With proper reduction of the FSH, LH and E2 levels and follicle diameter, repeated superovulation induction for IVF-ET can improve the ovarian response and pregnancy outcomes of the patients with adenomyosis or moderate to severe pelvic endometriosis after failure in the previous IVF-ET cycles with the ultra-long protocol.

Repeated superovulation induction after failure in previous IVF-ET cycles with the ultra-long protocol: Analysis of outcomes of clinical pregnancy / 中华男科学杂志

Objective@#To analyze the clinical outcomes of repeated superovulation induction in patients with adenomyosis or moderate to severe pelvic endometriosis after failure in previous IVF-ET cycles with the ultra-long protocol.@*METHODS@#We retrospectively analyzed the clinical data about 37 patients with adenomyosis or moderate to severe pelvic endometriosis in our center from 2009 to 2013, who underwent repeated IVF-ET after failure in the previous cycles with the ultra-long protocol, namely by injection of 2－6 ampoules of 3.75 mg gonadotropin-releasing hormone agonist (GnRH-a). All the patients met the following requirements: hCG-negative at 14 days after transfer, within 3－7 days after menstruation, and properly down-regulated serum follicle stimulating hormone (FSH) (<10 mIU/ml), luteinizing hormone (LH) (<10 mIU/ml), estradiol (E2) (<30 pg/ml), follicle diameter (<10 mm) and endometrial thickness, and received GnRH (Gonal-F, Serono) for ovulation induction. We compared the clinical and laboratory data and pregnancy outcomes between the first and repeated cycles before and after ovulation induction.@*RESULTS@#The repeated cycles, as compared with previous ones, showed significant increases in the antral follicle count (AFC) on the first day of stimulation (7.55 ± 1.86 vs 6.45 ± 2.5, P<0.05), number of follicles =≥14 mm in diameter on the hCG trigger day (7.81 ± 3.6 vs 5.56 ± 3.68, P<0.05), level of E2 (［2 362.15 ± 1 210.49］ vs ［1 749.22 ± 1 139.44］ pg/ml, P<0.05), and numbers of oocytes retrieved (7.51 ± 3.23 vs 4.78 ± 3.41, P<0.05) and embryos transferred (2.00 ± 0.33 vs 1.50 ± 0.67, P<0.05), exhibited a remarkably reduction in the dose of GnRH (［1 791.65 ± 1 889.41］ vs ［3 439.56 ± 1 836.53］ IU, P<0.05), and achieved a clinical pregnancy rate of 62.16%.@*CONCLUSIONS@#With proper reduction of the FSH, LH and E2 levels and follicle diameter, repeated superovulation induction for IVF-ET can improve the ovarian response and pregnancy outcomes of the patients with adenomyosis or moderate to severe pelvic endometriosis after failure in the previous IVF-ET cycles with the ultra-long protocol.