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Endoplasmic reticulum (ER) stress is associated with several aging-related diseases; however, the mechanism underlying age-related deterioration of oocyte quality is unclear. Here, we used post-ovulatory, in vivo aged mouse oocytes as a model. Super-ovulated oocytes harvested from the oviduct at 14 h and 20 h post-hCG injection were designated as ‘fresh’ and ‘aged’, respectively. Embryo development following IVF was compared between fresh, aged and ER stress-induced oocytes. Expression of the ER stress marker GRP78 was examined at each stage. To evaluate the effect of salubrinal, an ER stress suppressor, on embryo development following IVF, expression levels of GRP78 and phospho-eukaryotic initiation factor 2 alpha were compared between aged and salubrinal-treated aged oocytes. Embryo transfer of salubrinal-treated aged oocytes was performed to examine the safety of salubrinal. Similar to aged oocytes, ER stress-induced oocytes showed lower fertilization rates and poor embryo development. Following IVF, expression of GRP78 decreased with embryo development. GRP78 expression was significantly higher in aged oocytes than in fresh oocytes. Salubrinal lowered GRP78 levels and improved embryo development. No adverse effect of salubrinal treatment was found on the birth weight of pups or on organogenesis in mice. The limitation of this study was that protein kinase-like ER kinase was the only ER stress pathway examined; the role of IRE1 and ATF6 pathways was not considered. Nevertheless, salubrinal can significantly improve embryo development in in vivo aged oocytes undergoing ER stress. Hence, regulation of ER stress might represent a promising therapeutic strategy to overcome poor oocyte quality.

Oocyte vitrification is one of the methods for preserving fertility of cancer patients. In 2013, we reported a successful live birth using cryopreserved oocytes from a patient who contracted Ph-positive acute lymphoid leukemia at the retrieval age of 20. In this report, we described a second live birth from the same patient. The patient visited our clinic in November 2018 hoping to utilize vitrified oocytes cryopreserved in 2007. As a result, a day 3 single eight-cell stage embryo was transferred in a hormone replacement therapy cycle. She became pregnant and gave birth to a healthy girl (2,740 g) in September 2019. This is a case report of two live births from 10 matured oocytes that had been preserved for 12 years.

Aim This study aimed to assess the efficacy of the endometrial receptivity array (ERA) as a diagnostic tool and the impact of personalized embryo transfer (pET) for the treatment of patients with recurrent implantation failure (RIF) in Japan. Methods Fifty patients with a history of RIF with frozen-thawed blastocyst transfers were recruited from July, 2015 to April, 2016. Endometrial sampling for the ERA and histological dating and a pET according to the ERA were performed. The receptive (R) or non-receptive (NR) status of the endometrium as a result of the first ERA, endometrial dating, and pregnancy rates after the pET were analyzed. Results Of the patients with RIF, 12 (24%) were NR. Among them, eight (66.7%) were prereceptive. A clinical follow-up was possible in 44 patients who underwent the pET. The pregnancy rates were 58.8% per patient and 35.3% per first pET in the R patients and 50.0% per patient and 50.0% per first pET in the NR patients. Discrepancies between the ERA results and histological dating were seen more in the NR patients than in the R patients. Conclusions For patients with unexplained RIF, there is a significance in searching for their personal window of implantation (WOI) using the ERA, considering the percentage of those who were NR and the pregnancy rates that resulted from the pET. By transferring euploid embryos in a personal WOI, much better pregnancy rates are expected.

Study question Does a new system-the chip-sensing embryo respiration monitoring system (CERMs)-enable evaluation of embryo viability for potential application in a clinical IVF setting? Summary answer The system enabled the oxygen consumption rate of spheroids, bovine embryos and frozen-thawed human embryos to be measured, and this rate corresponded to the developmental potential of embryos. What is already known To date, no reliable and clinically suitable objective evaluation methods for embryos are available, which circumvent the differences in inter-observer subjective view. Existing systems such as the scanning electrochemical microscopy (SECM) technique, which enables the measurement of oxygen consumption rate in embryos, need improvement in usability before they can be applied to a clinical setting. Study design, size, duration This is a prospective original research study. The feasibility of measuring the oxygen consumption rate was assessed using CERMs for 9 spheroids, 9 bovine embryos and 30 redundant frozen-thawed human embryos. The endpoints for the study were whether CERMs could detect a dissolved oxygen gradient with high sensitivity, had comparable accuracy to the SECM measuring system with improved usability, and could predict the development of an embryo to a blastocyst by measuring the oxygen consumption rate. The relationship between the oxygen consumption rate and standard morphological evaluation was also examined. Participants/materials, setting, methods We developed a new CERMs, which enables the oxygen consumption rate to be measured automatically using an electrochemical method. The device was initially used for measuring a dissolved oxygen concentration gradient in order to calculate oxygen consumption rate using nine spheroids. Next, we evaluated data correlation between the CERMs and the SECM measuring systems using nine bovine embryos. Finally, the oxygen consumption rates of 30 human embryos, which were frozen-thawed on 2nd day after fertilization, were measured by CERMs at 6, 24, 48, 72 and 96 h after thawing with standard morphological evaluation. Furthermore, the developed blastocysts were scored using the blastocyst quality score (BQS), and the correlation with oxygen consumption rate was also assessed. Main results and the role of chance The device enabled the oxygen consumption rate of an embryo to be measured automatically within a minute. The oxygen concentration gradient profile showed excellent linearity in a distance-dependent change. A close correlation in the oxygen consumption rates of bovine embryos was observed between the SECM measuring system and CERMs, with a determination coefficient of 0.8203 (P = 0.0008). Oxygen consumption rates of human embryos that have reached the blastocyst stage were significantly higher than those of arrested embryos at 48, 72 and 96 h after thawing (P = 0.039, 0.004 and 0.049, respectively). Thus, in vitro development of frozen-thawed human embryos to the blastocyst stage would be predicted at 48 h after thawing (day 4) by measuring the oxygen consumption using CERMs. Although a positive linear relationship between BQS and the oxygen consumption rate was observed [the determination coefficient was R(2) = 0.6537 (P = 0.008)], two blastocysts exhibited low oxygen consumption rates considering their relatively high BQS. This suggests that morphology and metabolism in human embryos might not correlate consistently. Limitations, reasons for caution Transfer of the embryo and pregnancy evaluation was not performed. Thus, a correlation between oxygen consumption and the in vivo viability of embryos remains unknown. Clinical trials, including embryo transfer, would be desirable to determine a threshold value to elect clinically relevant, quality embryos for transfer. We utilized frozen-thawed human embryos in this study. The effect of these manipulations on the respiratory activity of the embryo is also unknown. Wider implications of the findings Selection of quality embryos, especially in a single embryo transfer cycle, by CERMs may have an impact on obtaining better clinical outcomes, albeit with clinical trials being required. Furthermore, the early determination of quality embryos by CERMs may enable the omission of long-term in vitro embryo culture to the blastocyst stage. CERMs is scalable technology that can be integrated into incubators and/or other embryo evaluation systems, such as the time-lapse systems, due to its chip-based architecture. Thus, CERMS would enable automatic measurement of oxygen consumption, under 5% CO2, in the near future, in order to reduce oxidative stress from exposure to atmospheric air. Study funding/competing interests This study was supported by grants from the Health and Labor Sciences Research Grant (H24-Hisaichiiki-Shitei-016). The authors have no conflicts of interest. Trial registration number Not applicable.

STUDY QUESTION Does in vivo aging of mouse oocytes affect mitochondrial function? SUMMARY ANSWER Mitochondrial function was impaired in post-ovulatory in vivo-aged mouse oocytes and microinjection of somatic cell mitochondria did not rescue poor fertilization and embryonic development rates. WHAT IS KNOWN ALREADY The mechanisms underlying the decline in oocyte quality associated with oocyte aging remain unknown, although studies have suggested that the decline is regulated by mitochondrial dysfunction. However, only a limited number of studies have provided direct evidence implicating mitochondrial dysfunction in oocyte quality during the aging of oocytes. STUDY DESIGN, SIZE, DURATION We used post-ovulatory, in vivo-aged mouse oocytes as a model for studying low-quality oocytes in oocyte aging. PARTICIPANTS/MATERIALS, SETTING, METHOD Superovulated oocytes released from the oviduct at 14 h and 20-24 h post-hCG injection were designated as 'fresh' and 'aged' oocytes, respectively. Membrane potentials and oxygen consumption in single oocytes were evaluated as measures of mitochondrial function in fresh and aged oocytes. Mitochondrial transcriptional factor A (TFAM) expression levels were examined by western blotting, and colocalization of mitochondria and TFAM was analyzed by measuring immunofluorescence in fresh and aged oocytes. IVF and blastocyst formation rates were calculated after oocyte microinjection with mitochondria derived from liver cells. MAIN RESULTS AND THE ROLE OF CHANCE The average mitochondrial membrane potential in fresh oocytes was significantly higher than that in aged oocytes (P

Oocyte quality is a key factor in determining embryo development; however, we have a poor understanding of what constitutes oocyte quality or the mechanisms governing it. Postovulatory aging of oocytes that have not been fertilized for a prolonged time after ovulation is known to significantly impair oocyte quality and subsequent embryo development after fertilization. Embryos derived from postovulatory-aged oocytes are prone to undergo apoptosis due to the decreased Bcl-2 expression. Postovulatory aging of oocytes changes the patterns of Ca(2+) oscillations at fertilization as a result of impaired Ca(2+) regulation in the endoplasmic reticulum. Moreover, postovulatory aging of oocytes impairs mitochondrial adenosine triphosphate production as a result of increasing oxidative stresses. Oxidative stresses also affect intracellular Ca(2+) regulation and impair embryo development after fertilization. Collectively, the mechanism of postovulatory oocyte aging might be involved in reactive oxygen species-induced mitochondrial injury followed by abnormal intracellular Ca(2+) regulation in the endoplasmic reticulum.

We recently reported that bezafibrate, a lipid-lowering drug of the fibrate class, administered in addition to clomiphene citrate (CC) successfully induced ovulation in CC-resistant polycystic ovary syndrome (PCOS) patients. We hypothesized that bezafibrate may directly affect ovarian follicle development. Insulin resistance and compensatory hyperinsulinemia are important for the pathogenesis of PCOS. In this study, we first examined the effects of tumor necrosis factor-alpha (TNF), which plays a role in insulin resistance, on follicle development by using the follicle culture system. TNF significantly inhibited follicle-stimulating hormone (FSH)-induced follicle development, 17beta-estradiol (E2) secretion, and ovulation rate in a dose-dependent manner. We then examined whether bezafibrate treatment could rescue the inhibition of FSH-induced follicle development and steroidogenesis by TNF. Bezafibrate treatment rescued inhibition of follicle development, secretion of E2, and ovulation rate by TNF. We examined the expression of peroxisome proliferator-activated receptor (PPAR) subtypes in mouse preantral follicles. As the protein expression of only PPARG was observed in mouse preantral follicles, we examined whether bezafibrate could affect follicle development and steroidogenesis through PPARG pathways. Treatment with GW1929, a selective PPARG agonist, restored inhibition of FSH-induced follicle development and steroidogenesis by TNF, whereas treatment with GW9662, a selective PPARG antagonist, canceled the restorative effects of bezafibrate. Collectively, the results in this study suggest that bezafibrate may directly exhibit a restorative effect on the inhibition of ovarian follicle development and steroidogenesis by TNF through the PPARG pathway.

Prostaglandins (PGs) are implicated in various physiological and pathological functions because of their vasoactive, mitogenic, and differentiating properties. PGs have long been known to participate in various female reproductive functions. The cyclooxygenase (COX) isozymes, COX-1 and COX2, are the rate-limiting enzymes of PGs. Gene targeting studies have revealed that COX-2, but not COX-1, derived PGs are essential for ovulation, fertilization, implantation, and decidualization. However, the roles of PGs in oocyte maturation remain controversial. We have clarified that COX-2-deficient mice have defective oocyte meiotic and cytoplasmic maturation associated with defective cumulus expansion in vivo and in vitro. Lack of COX-2-derived PGE2 leads to impaired cumulus cell-oocyte interactions, which are critical for the production of fertilization-competent oocytes. This review summarizes the published data regarding the roles of PGs in oocyte maturation especially in gene targeting studies.

We examined whether impairment of intracellular Ca2+ homeostasis is related to poor embryo development in in vitro-aged oocytes. We found that in vitro aging of mouse oocytes affected the patterns of Ca2+ oscillations at fertilization: these Ca2+ oscillations were lower in amplitude and higher in frequency compared with oocytes without in vitro aging. We also observed that the intracellular Ca2+ store was decreased in in vitro-aged oocytes. A decrease in the Ca2+ store induced by thapsigargin, a specific endoplasmic reticulum (ER) membrane Ca2+-ATPase inhibitor, resulted in a lower fertilization rate and in poorer embryo development. The frequency of Ca2+ oscillations was significantly increased at fertilization, whereas their amplitude was decreased in thapsigargin-treated oocytes. These results suggest that impairment of intracellular Ca2+ homeostasis (such as a decrease in the ER Ca2+ store) caused an alteration in Ca2+ oscillations and the poor embryo development in in vitro-aged oocytes. Bec...

A unicornate uterus with a rudimentary horn is a rare Mullerian duct abnormality. This uterine anomaly may cause variable gynecologic complications, including hematometra, endometriosis leading to acute pelvic pain, infertility, and obstetric complications, including miscarriage, preterm delivery, and rupture of the uterus, especially when the pregnancy implants in the rudimentary horn. To date, the standard treatment for the latter condition has been laparotomy, as patients usually experience massive abdominal hemorrhage or pregnancies too large to attempt laparoscopic removal. We report a case of a non-communicating rudimentary uterine horn pregnancy which was preoperatively diagnosed by ultrasonography, hysterofiberscopy, and magnetic resonance imaging, and then subsequently resected laparoscopically.

Mayer-Rokitansky-Küster-Hauser syndrome is a rare congenital anomaly characterized by congenital aplasia or hypoplasia of the uterus and vagina. We report a case of Mayer-Rokitansky-Küster-Hauser syndrome with multiple large pelvic masses diagnosed by three-dimensional computed tomography (CT) angiography.A 40-year-old woman with Mayer-Rokitansky-Küster-Hauser syndrome presented with an abdominal mass that had grown for 3 months. Magnetic resonance imaging (MRI) confirmed several solid masses, and normal bilateral ovaries were detected; three-dimensional CT revealed that these tumors were supplied from the right ovarian and uterine arteries, suggesting that they arose from the uterus. Accordingly, leiomyoma was suspected. Laparoscopic surgery was contraindicated, and the patient therefore underwent laparotomy. The masses were resected with the bilateral rudimentary uteri and fallopian tubes, and pathologic evaluation confirmed leiomyoma.Combined MRI and three-dimensional CT angiography can accurately evaluate the origin and anatomic properties of leiomyomas in patients with Mayer-Rokitansky-Küster-Hauser syndrome.

In recent years, postponement of marriage and childbearing in women of reproductive age has led to an increase in the incidence of age-related infertility. The reproductive aging process in women is assumed to occur due to a decrease in both the quantity and quality of the oocytes, with the ultimate result being a decline in fecundity. This age-related decline in fecundity is strongly dependent on oocyte quality, which is critical for fertilization and subsequent embryo development. Aged oocytes display increased chromosomal abnormality and dysfunction of cellular organelles, both of which factor into oocyte quality. In particular, mitochondrial dysfunction has been suggested as a major contributor to the reduction in oocyte quality as well as to chromosomal abnormalities in aged oocytes and embryos. Participation of oxidative stress in the oocyte aging process has been proposed because oxidative stress has the capacity to induce mitochondrial dysfunction and directly damage many intracellular components of the oocytes such as lipids, protein, and DNA. In an attempt to improve mitochondrial function in aged oocytes, several therapeutic strategies have been investigated using both animal models and assisted reproductive technology. Here, we review the biological mechanisms and present status of therapeutic strategies in the female reproductive aging field and indicate possible future therapeutic strategies.

Postovulatory aging of oocytes significantly affects embryonic development. Also, altered Ca2+ oscillation patterns can be observed in fertilized, aged mouse oocytes. Because Ca2+ oscillations depend on Ca2+ release and reuptake in the endoplasmic reticulum, and the latter relies on ATP availability, we simultaneously measured changes in intracellular ATP concentration ([ATP]i) and Ca2+ oscillations in fresh and aged mouse oocytes. We continuously assessed changes in [ATP]i from intracellular free Mg2+ concentration measured by fluorescent dye Magnesium Green (MgG) while intracellular Ca2+ concentration ([Ca2+]i) was monitored by Fura-PE3. At fertilization, MgG fluorescence was transiently increased concomitant with the first transient elevation in [Ca2+]i, indicating a relative decrease in [ATP]i. In fresh oocytes, it was quickly followed by a significant decrease below baseline, indicating a relative increase in [ATP]i. In contrast, in aged oocytes, such a decrease in MgG fluorescence was not observed. In a separate experiment, ATP content in fresh and aged oocytes was determined in vitro by the luciferin-luciferase assay. Intracellular ATP contents measured in vitro were comparable in unfertilized fresh and aged oocytes. Intracellular ATP content at 5 h after fertilization was increased in both oocytes, where fresh oocytes showed a significantly higher intracellular value than aged oocytes. These findings suggest that aged mouse oocytes fail to readjust the level of intracellular ATP at fertilization. Relative deficiencies of ATP at fertilization might lead to an altered Ca2+ oscillation pattern and poor developmental potency, which is commonly noted in aged oocytes.

IntroductionElective single embryo transfer (SET) is a reasonable optionfor avoiding multiple pregnancies in patients who undergoassisted reproductive technology (ART) treatment [1, 2]. TheJapan Society of Obstetrics and Gynecology (JSOG) recom-mends SET for patients under 35 years of age and for thosewho have undergone ≤2 treatment cycles since 2008. TheJSOG recommendation increased the use of the SET tech-nique from 49.9 % (52,800/105,812) of all embryo transfercyclesin2007to73%(106,758/146,286)in2010[3,4].Asaresult, the proportion of all embryo transfer cycles that result-ed in multiple pregnancies decreased from 3.0 % in 2007 to1.3 % in 2010 [3, 4].Multiplepregnancies may occur evenifSETisperformed.Todate,17casesinvolvingtwinortripletpregnanciesaftertheSEThavebeenreported[5].Inthe general population,mono-zygotic twins have been calculated to account for 0.4–0.45 %ofalllivebirths[6,7].InpatientsundergoingART,thisrateisapproximately twice that of spontaneous pregnancies [8, 9].Theoretically,twinsresultingfromaSETprocedureshouldbemonozygotic.However,areviewoftheliteraturesuggeststhat4 cases of dizygotic twin pregnancies have been reported inpatients undergoing the SET technique [10–12]. Here, wepresent a fifth case and a review of the literature concerningthis phenomenon.Case reportA 39-year-old, nulligravida woman and her 44-year-old hus-band had an 8-year history of infertility. She had regular men-strual cycles occurring every 28 days and lasting 7 days, andwas negative for Chlamydia trachomatis IgAandIgGantibod-ies. She had bilateral tubal patency by hysterosalpingography.Her husband’s semen analysis showed normozoospermia,based on the 2010 World Health Organization criteria.The woman underwent in vitro fertilization (IVF) and em-bryo transfer with a long-protocol, gonadotropin-releasing hor-mone agonist because of unexplained infertility. Nine cumulusoocytecomplexes(COCs)wereaspiratedandtheseCOCsweresubjected to IVF. Six fertilized oocytes with two pronuclei wereobserved 20 h after insemination. Although one embryo at themorulastagewastransferredtotheuterusondayfourafterIVF,she did not become pregnant. The remaining four morula-stageembryos with good morphology were subjected to vitrificationin a solution containing 40 % (v ol/vol) ethylene glycol, 18 %(wt/vol) Ficoll 70, and 0.3 mol/L trehalose [ 13]. After 2 monthsof IVF treatment, the patient became pregnant spontaneously,but this resulted in a biochemical pregnancy. Four months aftervitrification of the embryos, four embryos were warmed for ascheduled embryo transfer, according to the patient ’snaturalmenstrual cycle. Ovulation was confirmed by follicular moni-toringwithtransvaginalultrasonographyonday17ofthecycle.The embryo transfer was planned 5 days after the ovulation.Warmingofmorula-stageembryoswasperformedonthedaybefore the scheduled embryo transfer. Three surviving morula-stage embryos were cultured, a fter warming in Global Medium(LifeGlobal, Gilford, CT, USA) supplemented with 10 % syn-thetic serum substitute (Irvine Scientific, Santa Ana, CA, USA)for 18 h. One embryo showed further development and reachedthe expanded blastocyst stage. The expanded blastocyst wastransferred into the patient’s uterus. Ten days after embryotransfer, her pregnancy test was positive. Two gestational sacswith fetal heart beats in each gestational sac were observed by

It is well established that age-related decline of a woman's fertility is related to the poor developmental potential of her gametes. The age-associated decline in female fertility is largely attributable to the oocyte aging caused by ovarian aging. Age-associated oocyte aging results in a decrease in oocyte quality. In contrast to ovarian aging, there is a concept of postovulatory oocyte aging. Postovulatory aging of oocytes, not being fertilized for a prolonged time after ovulation, is known to significantly affect the development of oocytes. Both categories of oocyte aging have similar phenotypes of reproductive failure. However, the mechanisms of the decline in oocyte quality are not necessarily equivalent. An age-dependent increase in aneuploidy is a key determinant of oocyte quality. The reduced expression of molecules regulating cell cycle control during meiosis might be involved in the age-dependent increase in aneuploidy. The mechanism of age-associated oocyte aging might be involved in mitochondrial dysfunction, whose etiologies are still unknown. Alternatively, the mechanism of postovulatory oocyte aging might be involved in reactive oxygen species-induced mitochondrial injury pathways followed by abnormal intracellular Ca2+ regulation of the endoplasmic reticulum. We suggest that future research into the mechanism of oocyte aging will be necessary to develop a method to rescue the poor developmental potential of aged oocytes.

In vivo post-ovulatory aging of oocytes significantly affects the development of oocytes and embryos. Also, oocyte aging alters the regulation of the intracellular calcium concentration, thus affecting Ca(2+) oscillations in fertilized oocytes. Because reactive oxygen species (ROS) are known to significantly perturb Ca(2+) homeostasis mainly through direct effects on the machinery involved in intracellular Ca(2+) storage, we hypothesized that the poor development of aged oocytes that may have been exposed to oxidative stress for a prolonged time might arise from impaired Ca(2+)-oscillation-dependent signaling. The fertilization rates of aged oocytes and of fresh oocytes treated with 100 microM hydrogen peroxide (H(2)O(2)) for 10 min were significantly lower than that of fresh oocytes. Comparing within the fertilized oocytes, blastocyst formation was decreased while embryo fragmentation was increased similarly in the aged and H(2)O(2)-treated fresh oocytes. The frequency of Ca(2+) oscillations was significantly increased whereas the amplitude of individual Ca(2+) transients was lowered in the aged and H(2)O(2)-treated fresh oocytes. The rates of rise and decline in individual Ca(2+) transients were decreased in these oocytes, indicating impaired Ca(2+) handling. When lipid peroxidation was assessed using 4,4-difluoro-5-(4-phenyl-1,3-buttadienyl)-4-bora-3a, 4a-diaza-s-indacene-3-undecanoic acid (C11-BODIPY) in unfertilized oocytes placed in a 5% CO(2) in air atmosphere, the green fluorescence (indicating lipid peroxidation) increased faster in the aged oocytes than in the fresh oocytes. Furthermore, the green fluorescence in the aged oocytes was already approximately 20 times higher than that in the fresh oocytes at the beginning of the measurements. These findings support the idea that Ca(2+) oscillations play a key role in the development of fertilized aged oocytes.

A 46 year-old man with hypertrophic obstructive cardiomyopathy (HOCM) was referred to this clinic complaining of shortness of breath. His symptoms remained even after he had been treated with bisoprolol, lisinopril, and verapamil. We started treating him with cibenzoline, instead of verapamil. Continuous-wave Doppler examination revealed a marked decrease from 95.9 mm Hg to 8.8 mmHg in the left ventricular outflow tract pressure gradient after administration of cibenzoline, and the symptom disappeared. The electrical axis of the electrocardiogram deviated from +53 to +95 degrees, and the QRS interval was increased from 0.095 to 0.114 seconds. By the M-mode echocardiogram, the interventricular septum was observed moved paradoxically in the early, systolic phase. We suggest the possibility that cibenzoline modifies intraventricular conduction and causes asynchronous contraction of the left ventricle, resulting in decrease in the left ventricular outflow tract pressure gradient.

Aging of oocytes, being not fertilized after ovulation for a prolonged time, considerably affects normal development of the fertilized oocyte. We examined effects of the aging on a series of highly repetitive Ca2+ transients commonly seen in fertilized mouse oocytes (Ca2+ oscillations). Frequency of Ca2+ oscillations in the aged oocyte [20 hrs after induction of superovulation by i.p. human chorionic gonadotropin (hCG)] was significantly higher (34.1 +/- 5.8 l/hr) than the fresh oocyte (14 hr post-hCG, 21.8 +/- 7.9 l/hr). Rates of rise and fall of individual Ca2+ transient in the aged oocyte were significantly slower than the fresh oocyte, whereas durations of individual Ca2+ transients were similar. When extracellular Ca2+ was raised from 2.04 mM to 5.00 mM, aged oocytes showed significant prolongation of the duration of individual Ca2+ transient, that resulted in a sustained elevation of intracellular Ca2+ ([Ca2+]i) in 33% of the aged oocyte. Transient increase in [Ca2+]i by photolysis of a caged Ca2+, Nitr-5, injected into cytoplasm was completely restored in the fresh oocyte [fluorescence intensity of [Ca2+]i indicator dye Fluo-3 (F480) returned to 97 +/- 2% of the control level, time constant = 37 +/- 9 sec]. In contrast, in the aged oocyte, restoration of F480 following Nitr-5 photolysis was incomplete (115 +/- 12% of the control) and slow (time constant = 64 +/- 23 sec). Because inhibition of the Ca2+ pump of the endoplasmic reticulum (ER) by 5 microM thapsigargin almost completely inhibited restoration of F480 following Nitr-5 photolysis in the fresh oocyte, we conclude that the aging-related changes in Ca2+ oscillations may be accounted for by dysfunction of intracellular Ca2+ regulation, presumably of the Ca2+ pump of the ER.

Background Oocyte retrieval failure following an ovarian hyperstimulation protocol is uncommon in assisted reproductive technology (ART) programs. We analyzed the predictive factors for oocyte retrieval failure following controlled ovarian hyperstimulation (COH) with gonadotropin-releasing hormone (GnRH) agonist and GnRH antagonist protocols in ART programs. Methods This study was a retrospective cohort observational study. In total, 744 cycles from 361 patients who underwent controlled ovarian hyperstimulation with GnRH agonist long protocol or antagonist protocol were analyzed. Treatment cycles with oocyte retrieval failure and with one or more oocytes retrieved were compared to determine predictive factors for oocyte retrieval failure using univariate and multilevel multivariate logistic regression analyses. Results Oocyte retrieval failure occurred in 38 cycles (5.1 %). The oocyte retrieval failure rate of the GnRH antagonist protocol (8.1 %) was significantly higher than that of the GnRH agonist long protocol (3.7 %). On multilevel multivariate logistic analysis, cycles with GnRH antagonist protocol (odds ratio [OR] 3.06, 95 % confidence interval [CI] 1.05–8.96), estradiol level on the day of human chorionic gonadotropin (hCG) injection (OR 0.997, 95 % CI 0.996–0.998), and luteinizing hormone (LH) level on the day of hCG injection (OR 1.19, 95 % CI 1.06–1.33) were independent predictive factors for oocyte retrieval failure. The efficacy of estradiol and LH levels on the day of hCG injection for predicting oocyte retrieval failure was evaluated using receiver operating characteristic curves. In all cycles, the areas under the curve (AUCs) for estradiol and LH were 0.84 and 0.63, respectively, for all cycles; 0.84 and 0.52, respectively, for cycles with GnRH agonist long protocol; and 0.81 and 0.82, respectively, for cycles with GnRH antagonist protocol. Conclusions Our results suggest that in cycles with GnRH antagonist protocol, the levels of estradiol and LH on the day of hCG injection might be predictive factors for oocyte retrieval failure. This relationship may provide useful information to both patients and physicians for developing better COH protocols in ART programs.