The role of androgen hormones in early follicular development

Testosterone therapy for women with poor ovarian response undergoing IVF: a meta-analysis of randomized controlled trials

PURPOSE

The aim of the present systematic review and meta-analysis was to summarize evidence on the effectiveness of testosterone supplementation for poor ovarian responders (POR) on IVF outcomes. The primary outcome was live birth rate (LBR); secondary outcomes were clinical pregnancy rate (CPR), miscarriage rate (MR), total and MII oocytes, and total embryos.

METHODS

This meta-analysis of randomized controlled trials (RCTs) evaluates the effects of testosterone administration before/during COS compared with a control group in patients defined as POR. The primary outcome was live birth rate (LBR); secondary outcomes were clinical pregnancy rate (CPR), miscarriage rate (MR), total and MII oocytes, and total embryos. Pooled results were expressed as risk ratio (RR) or mean differences (MD) with 95% confidence interval (95% CI). Sources of heterogeneity were investigated through sensitivity and subgroup analysis. All analyses were performed by using the random-effects model.

RESULTS

Women receiving testosterone showed higher LBR (RR 2.29, 95% CI 1.31-4.01, p = 0.004), CPR (RR 2.32, 95% CI 1.47-3.64, p = 0.0003), total oocytes (MD = 1.28 [95% CI 0.83, 1.73], p < 0.00001), MII oocytes (MD = 0.96 [95% CI 0.28, 1.65], p = 0.006), and total embryos (MD = 1.17 [95% CI 0.67, 1.67], p < 0.00001) in comparison to controls, with no difference in MR (p = ns). Sensitivity and subgroup analysis did not provide statistical changes to the pooled results.

CONCLUSIONS

Testosterone therapy seems promising to improve the success at IVF in POR patients. Further RCTs with rigorous methodology and inclusion criteria are still mandatory.

Mojave Yucca (Yucca Schidigera Roezl) Effects on Female Reproduction a Review

Yucca is an important source of biologically active substances such as steroidal saponins and stilbenes providing many beneficial effects when administered to humans and other animals. These substances offer a great potential in the prevention and treatment of current civilized diseases as well as to their: antioxidant, hypocholesterolaemic, anti-inflammatory, phytoestrogenic, pro-apoptotic, anti-proliferative, and anti-carcinogenic properties. This review focuses on the roles of two main yucca constituent groups and their ability to modulate ovarian functions and female reproductive performance. Both the biological activity of yucca substances and the mechanisms of their actions on ovaries are still incompletely understood. Thus, the direct effects of yucca extract on ovarian cells in animal models under in vitro conditions, as well as actions after yucca consumption will be discussed.

Transcripts Encoding the Androgen Receptor and IGF-Related Molecules Are Differently Expressed in Human Granulosa Cells From Primordial and Primary Follicles

Bidirectional cross talk between granulosa cells and oocytes is known to be important in all stages of mammalian follicular development. Insulin-like growth factor (IGF) signaling is a prominent candidate to be involved in the activation of primordial follicles, and may be be connected to androgen-signaling. In this study, we interrogated transcriptome dynamics in granulosa cells isolated from human primordial and primary follicles to reveal information of growth factors and androgens involved in the physiology of ovarian follicular activation. Toward this, a transcriptome comparison study on primordial follicles (n = 539 follicles) and primary follicles (n = 261 follicles) donated by three women having ovarian tissue cryopreserved before chemotherapy was performed. The granulosa cell contribution in whole follicle isolates was extracted in silico. Modeling of complex biological systems was performed using IPA® software. We found the granulosa cell compartment of the human primordial and primary follicles to be extensively enriched in genes encoding IGF-related factors, and the Androgen Receptor (AR) enriched in granulosa cells of primordial follicles. Our study hints the possibility that primordial follicles may indeed be androgen responsive, and that the action of androgens represents a connection to the expression of key players in the IGF-signaling pathway including IGF1R, IGF2, and IGFBP3, and that this interaction could be important for early follicular activation. In line with this, several androgen-responsive genes were noted to be expressed in both oocytes and granulosa cells from human primordial and primary follicle. We present a detailed description of AR and IGF gene activities in the human granulosa cell compartment of primordial and primary follicles, suggesting that these cells may be or prepare to be responsive toward androgens and IGFs.

Histopathological changes in androgenized ovaries are recovered by melatonin treatment

Nandrolone decanoate (ND) is a synthetic steroid, which promotes adverse effects on the ovarian tissue, and melatonin (MLT) exhibits a number of beneficial properties in the reproductive system. This study evaluated the general features of the ovarian tissue and the immunoexpression of sex steroid receptors in ND-treated rats that were submitted to short-term melatonin treatment. Adult rats received mineral oil (control group) and ND at doses of 7.5 mg/kg for 15 days (ND-treated group). The treatment with MLT (10mg/kg for 7 days) was given alone, before or in combination with ND. All ND-treated animals showed persistent dioestrus. In the androgenized groups that received MLT, ovarian morphology and size, and the number/area of corpora lutea were recovered. The number of healthy and atretic follicles was recovered when MLT was administered prior to ND; this was similar to the ovaries of control and MLT groups. There was a decrease in estrogen receptors immunostaining in the follicles of androgenized rats that were treated with MLT, and pretreatment with MLT reduced the expression of androgen receptor in atretic follicles and corpora lutea, when compared with ND-treated group. We conclude that MLT treatment recovered the histopathological aspects of the androgenized ovaries, and MLT pretreatment was the most effective.

The VEGF and PEDF levels in the follicular fluid of patients co- treated with LETROZOLE and gonadotropins during the stimulation cycle

BACKGROUND

Previous studies have shown that androgens, in addition to serving as precursors for ovarian estrogen synthesis, also have a fundamental role in primate ovarian follicular development by augmentation of FSH receptor expression on granulosa cells. Recent studies have shown that aromatase inhibitor, letrozole, improves ovarian response to FSH in normal and poor responder patients, possibly by increasing intraovarian androgen levels. Studies in mice also showed an effect of letrozole to increase pigment epithelium-derived factor (PEDF) and to lower vascular epithelial growth factor (VEGF), which might be expected to reduce the risk of ovarian hyperstimulation syndrome (OHSS) with stimulation. The aim of this study was to compare the VEGF and PEDF levels in the follicular fluids of normal responders treated with letrozole and gonadotropins during the ovarian stimulation with patients treated with gonadotropins only.

METHODS

A single center, prospective clinical trial. We collected follicular fluid from 26 patients, on a GnRH antagonist protocol, dual triggered with hCG and GnRH agonist. The patients in one group were co-treated with letrozole and gonadotropins during the ovarian stimulation and the patients in the other group were treated with gonadotropins only. VEGF, PEDF, estrogen, progesterone and testosterone levels were measured by ELISA kits.

RESULTS

The age of the patients, the total dose of gonadotropins and the number of oocytes were comparable between the two groups. In the follicular fluid, the estrogen levels (2209 nmol/l vs. 3280 nmol/l, p = 0.02) were significantly decreased, and the testosterone levels (246.5 nmol/l vs. 40.7 nmol/l, p < 0.001) were significantly increased in the letrozole group compared to the gonadotropin only group. The progesterone levels (21.4 μmol/l vs. 17.5 p = NS) were comparable between the two groups. The VEGF levels (2992 pg/ml vs. 1812 pg/ml p = 0.02) were significantly increased and the PEDF levels (9.7 ng/ml vs 17.3 ng/ml p < 0.001) were significantly decreased in the letrozole group.

CONCLUSIONS

Opposite to observations in the mouse, we found that VEGF levels were increased and PEDF levels were decreased in the follicular fluid in patients treated with letrozole during the stimulation cycles. Further investigation is required to determine if patients treated with letrozole during the IVF stimulation protocol are at increased risk for developing OHSS as a result of these findings.

Zebrafish androgen receptor is required for spermatogenesis and maintenance of ovarian function

The androgen receptor (AR) is a nuclear receptor protein family member and inducible transcription factor that modulates androgen target gene expression. Studies using a mouse model confirmed the need for ar in reproductive development, particularly spermatogenesis. Here, we investigated the role of ar in zebrafish using CRISPR/Cas9 gene targeting technology. Targeted disruption of ar in zebrafish increases the number of female offspring and increases offspring weight. In addition, ar-null male zebrafish have female secondary sex characteristics. More importantly, targeted disruption of ar in zebrafish causes male infertility via defective spermatogenesis and female premature ovarian failure during growth. Mechanistic assays suggest that these effects are caused by fewer proliferated cells and more apoptotic cells in ar-null testes. Moreover, genes involved in reproductive development, estradiol induction and hormone synthesis were dys-regulated in testes and ovaries and the reproductive-endocrine axis was disordered. Our data thus suggest that the zebrafish ar is required for spermatogenesis and maintenance of ovarian function, which confirms evolutionarily conserved functions of ar in vertebrates, as well as indicates that ar-null zebrafish are a suitable model for studying pathologic mechanisms related to androgen disorders.

High-Fat, High-Sugar Diet Disrupts the Preovulatory Hormone Surge and Induces Cystic Ovaries in Cycling Female Rats

Diet-induced obesity has been associated with various metabolic and reproductive disorders, including polycystic ovary syndrome. However, the mechanisms by which obesity influences the reproductive system are still not fully known. Studies have suggested that impairments in hormone signaling are associated with the development of symptoms such as acyclicity and ovarian cysts. However, these studies have often failed to address how these hormonal changes arise and how they might contribute to the progression of reproductive diseases. In the present study, we used a high-fat, high-sugar (HFHS) diet to induce obesity in a female rodent model to determine the changes in critical reproductive hormones that might contribute to the development of irregular estrous cycling and reproductive cycle termination. The HFHS animals exhibited impaired estradiol, progesterone (P4), and luteinizing hormone (LH) surges before ovulation. The HFHS diet also resulted in altered basal levels of testosterone (T) and LH. Furthermore, alterations in the basal P4/T ratio correlated strongly with ovarian cyst formation in HFHS rats. Thus, this model provides a method to assess the underlying etiology of obesity-related reproductive dysfunction and to examine an acyclic reproductive phenotype as it develops.

Preventive Effect and Safety of a Follicle Stimulating Hormone Inhibitory Formulation Containing a Mixture of Coicis Semen and Artemisia capillaris for Precocious Puberty: A Preliminary Experimental Study Using Female Rats

BACKGROUND

Precocious puberty is a common endocrine disease in children. Inappropriate activation of hypothalamic-pituitary-gonadal axis leads to the development of secondary sexual characteristics at an earlier age than normal children and causes short stature in adulthood.

OBJECTIVES

The aim of this study is to evaluate the preventive effects of a herbal formulation containing a mixture of Coicis Semen and Artemisia capillaris (hEIF extract) on precocious puberty.

METHODS

The preventive effect of hEIF extract on precocious puberty in rats was evaluated by measuring blood component after 3 weeks of treatment via oral administration. Network pharmacological analyses were performed to predict the bioactive components of hEIF extract.

RESULTS

In vivo studies showed that hEIF extract significantly reduced follicle stimulating hormone (FSH) levels. After treatment with 200 mg/kg of hEIF extract, the FSH level was 5.33 ± 1.10 ng/mL, whereas the FSH level in the vehicle group was 46.73 ± 0.80 ng/mL. Moreover, the use of hEIF extract did not stimulate body growth and bone accretion in rats. The network pharmacological analysis led to the identification of multiple targets of hEIF extract related to lipolysis and the female sex hormone-related pathways.

CONCLUSION

hEIF extract can be used as an FSH inhibitor for the treatment of precocious puberty.

The concentration-dependent effect of progesterone on follicle growth in the mouse ovary

Follicle growth in the mammalian ovary is coordinately controlled by multiple factors to sustain periodic ovulation. In this study, we investigated the role of progesterone on follicle growth in the mouse ovary. As the concentration of progesterone changes during the estrus cycle, we cultured the sliced mouse ovary in a medium containing 10 ng/ml, 100 ng/ml, and 1 μg/ml progesterone. Progesterone promoted the growth of primordial to primary follicles at 100 ng/ml, while it suppressed the growth of secondary follicles at 1 μg/ml. Follicles at other developmental stages in the cultured ovary were unaffected with different concentrations of progesterone. The number of ovulated oocytes increased in the medium containing 100 ng/ml progesterone but decreased in the presence of 1 μg/ml progesterone. Follicles expressed two types of progesterone receptors, progesterone receptor (PGR) and PGR membrane component 1 (PGRMC1). While PGR shows transient expression on granulosa cells of Graafian follicles, PGRMC1 expresses in granulosa cells of developing follicles. These results suggest that progesterone controls the growth of developing follicles through PGRMC1. Our study shows that the effect of progesterone on ovulation and follicle growth in mouse ovary is dependent on the concentration of progesterone and the follicle stage.

Selective deletion of Pten in theca-interstitial cells leads to androgen excess and ovarian dysfunction in mice

Theca cell-selective Pten mutation (tPtenMT) in mice resulted in increases in PDK1 and Akt phosphorylation, indicating an over-activation of PI3K signaling in the ovaries. These mice displayed elevated androgen levels, ovary enlargement, antral follicle accumulation, early fertility loss and increased expression of Lhcgr and genes that are crucial to androgenesis. These abnormalities were partially reversed by treatments of PI3K or Akt inhibitor. LH actions in Pten deficient theca cells were potentiated. The phosphorylation of Foxo1 was increased, while the binding of Foxo1 to forkhead response elements in the Lhcgr promoter was reduced in tPtenMT theca cells, implying a mechanism by which PI3K/Akt-induced upregulation of Lhcgr in theca cells might be mediated by reducing the inhibitory effect of Foxo1 on the Lhcgr promoter. The phenotype of tPtenMT females is reminiscent of human PCOS and suggests that dysregulated PI3K cascade in theca cells may be involved in certain types of PCOS pathogenesis.

A model of ovulatory regulation examining the effects of insulin-mediated testosterone production on ovulatory function

Polycystic ovary syndrome (PCOS), a common cause of infertility in women, is often accompanied by abnormal reproductive and metabolic hormone levels. Specifically, androgens such as testosterone are elevated in many PCOS women, and the syndrome itself is frequently associated with insulin resistance, which leads to hyperinsulinemia, i.e., elevated insulin. Although the precise role of insulin in ovulatory function is unclear, its role in ovulatory dysfunction is often linked to the effects of increased ovarian androgen production. We present a mathematical model of the menstrual cycle that incorporates regulation by the pituitary-ovarian axis and mechanisms of ovarian testosterone production. We determine a physiological role for testosterone in the normal ovulatory cycle and study the role of hyperinsulinemia in pathological regulation of the cycle. Model results indicate increased ovulatory disruption with elevated insulin-mediated testosterone production and suggest that variations in the response of ovarian follicles to essential signals can alter the degree to which hyperinsulinemia disrupts the ovulatory cycle. The model also provides insight into the various PCOS phenotypes and the severity of ovulatory dysfunction.

Ovarian sex steroid receptors and sex hormones in androgenized rats

This study evaluated for the first time the effects of different doses of the anabolic steroid nandrolone decanoate (ND) on the expression of ovarian steroid receptors (AR, ER-α (ESR1) and ER-β (ESR2)) and related sex hormones after treatment and recovery periods in adult rats. The animals were injected subcutaneously with doses of ND (1.87, 3.75, 7.5 or 15 mg/kg b.w.) or mineral oil (control group) for 15 days, and the experimental groups were divided into three periods of evaluation: (a) ND treatment for 15 days, (b) ND treatment and recovery for a period of 30 days and (c) ND treatment and recovery for a period of 60 days. Estrous cycle was monitored daily. At the end of each period, rats were killed for collection of blood and ovaries. Persistent diestrus occurred in all rats during ND treatment and after 30-day recovery. The highest dose of ND was able to maintain all rats arrested at diestrus until 60-day recovery. The expression of steroid receptors varied in a dose- and period-dependent manner, having a more pronounced response with the dose of 15 mg ND/kg. ND treatment increased serum levels of testosterone, 17β-estradiol and dihydrotestosterone, especially at the highest doses of 7.5 and 15 mg ND/kg. No change was observed in the levels of follicle-stimulating hormone (FSH), whereas levels of the luteinizing hormone (LH) varied according to the dose and period. In conclusion, the ovarian sex steroid receptors and sex hormones were restored only at lower doses of ND and after a longer period of recovery.

Developmental programming: rescuing disruptions in preovulatory follicle growth and steroidogenesis from prenatal testosterone disruption

BACKGROUND

Prenatal testosterone (T) excess from days 30-90 of gestation disrupts gonadotropin surge and ovarian follicular dynamics and induces insulin resistance and functional hyperandrogenism in sheep. T treatment from days 60-90 of gestation produces a milder phenotype, albeit with reduced fecundity. Using this milder phenotype, the aim of this study was to understand the relative postnatal contributions of androgen and insulin in mediating the prenatal T induced disruptions in ovarian follicular dynamics.

METHODS

Four experimental groups were generated: 1) control (vehicle treatment), 2) prenatal T-treated (100 mg i.m. administration of T propionate twice weekly from days 60-90 of gestation), 3) prenatal T plus postnatal anti-androgen treated (daily oral dose of 15 mg/kg/day of flutamide beginning at 8 weeks of age) and 4) prenatal T and postnatal insulin sensitizer-treated (daily oral dose of 8 mg/day rosiglitazone beginning at 8 weeks of age). Follicular response to a controlled ovarian stimulation protocol was tested during their third breeding season. Main outcome measures included the determination of number and size of ovarian follicles and intrafollicular concentrations of steroids.

RESULTS

At the end of the controlled ovarian stimulation, the number of follicles approaching ovulatory size (≥6 mm) were ~35 % lower in prenatal T-treated (6.5 ± 1.8) compared to controls (9.8 ± 2.0). Postnatal anti-androgen (10.3 ± 1.9), but not insulin sensitizer (5.0 ± 0.9), treatment prevented this decrease. Preovulatory sized follicles in the T group had lower intrafollicular T, androstenedione, and progesterone compared to that of the control group. Intrafollicular steroid disruption was partially reversed solely by postnatal insulin sensitizer treatment.

CONCLUSIONS

These results demonstrate that the final preovulatory follicular growth and intrafollicular steroid milieu is impaired in prenatal T-treated females. The findings are consistent with the lower fertility rate reported earlier in these females. The finding that final follicle growth was fully rescued by postnatal anti-androgen treatment and intrafollicular steroid milieu partially by insulin sensitizer treatment suggest that both androgenic and insulin pathway disruptions contribute to the compromised follicular phenotype of prenatal T-treated females.

Early ovarian follicular development in prepubertal Wistar rats acutely exposed to androgens

Androgens may directly modulate early ovarian follicular development in preantral stages and androgen excess before puberty may disrupt this physiological process. Therefore, the aim of this study was to investigate the dynamics of follicular morphology and circulating androgen and estradiol levels in prepubertal Wistar rats acutely exposed to androgens. Prepubertal female Wistar rats were distributed into three groups: control, equine chorionic gonadotropin (eCG) intervention and eCG plus dehydroepiandrosterone (DHEA) intervention (eCG+DHEA). Serum DHEA, testosterone and estradiol levels were determined, and ovarian morphology and morphometry were assessed. The eCG+DHEA group presented increased serum estradiol and testosterone levels as compared with the control group (P<0.01), and higher serum DHEA concentration v. the eCG-only and control groups (P<0.01). In addition, the eCG+DHEA group had a higher number of, and larger-sized, primary and secondary follicles as compared with the control group (P<0.05). The eCG group presented intermediate values for number and size of primary and secondary follicles, without significant differences as compared with the other two groups. The number of antral follicles was higher in the eCG+DHEA and eCG groups v. controls (P<0.05). The number of primordial, atretic and cystic follicles were similar in all groups. In conclusion, the present experimental model using an acute eCG+DHEA intervention was useful to investigate events involved in initial follicular development under hyperandrogenic conditions, and could provide a reliable tool to study defective follicular development with possible deleterious reproductive consequences later in life.

Effect of Prenatal and Neonatal Anti-Androgen Flutamide Treatment on Aquaporin 5 Expression in the Adult Porcine Ovary

The growth of ovarian follicles is accompanied by fluid-filled antrum formation. Water movement within the follicular wall is predominantly transcellular via membranous water channels named aquaporins (AQPs). Androgens are important regulators of mammalian folliculogenesis, and their prenatal and/or neonatal deficiency affects female fertility in adulthood. Therefore, this study was performed to determine whether gestational or neonatal exposure to the anti-androgen flutamide influences androgen-dependent AQP5 expression in pre-antral and large antral follicles of adult pigs. Flutamide was injected into pregnant gilts between days 80 and 88 of gestation and into female piglets between days 2 and 10 post-natally. The ovaries were collected from flutamide-treated and non-treated (control) sexually mature pigs. In pre-antral follicles, AQP5 mRNA and protein levels were both downregulated following maternal (p < 0.01 and p < 0.01, respectively) and neonatal (p < 0.01 and p < 0.01, respectively) flutamide exposure. Likewise, the expression of mRNA (p < 0.01 and p < 0.001, respectively) and protein (p < 0.05 and p < 0.01, respectively) for AQP5 were diminished in large antral follicles in both groups. Immunohistochemistry showed decreased intensity of AQP5 immunoreaction in pre-antral (p < 0.01) and large antral (p < 0.001) follicles following flutamide treatment. Moreover, radioimmunological analysis revealed that changes observed in AQP5 expression corresponded with diminished follicular androgens production after both maternal (p < 0.05 and p < 0.05, respectively) and neonatal (p < 0.05 and p < 0.01, respectively) flutamide administration. Therefore, AQP5 appears to be a potential regulator of follicular fluid accumulation, under androgen control, and may be a key factor in antral follicle growth.

High levels of testosterone inhibit ovarian follicle development by repressing the FSH signaling pathway

The effect of high concentrations of testosterone on ovarian follicle development was investigated. Primary follicles and granulosa cells were cultured in vitro in media supplemented with a testosterone concentration gradient. The combined effects of testosterone and follicle-stimulating hormone (FSH) on follicular growth and granulosa cell gonadotropin receptor mRNA expression were also investigated. Follicle growth in the presence of high testosterone concentrations was promoted at early stages (days 1-7), but inhibited at later stage (days 7-14) of in vitro culture. Interestingly, testosterone-induced follicle development arrest was rescued by treatment with high concentrations of FSH (400 mIU/mL). In addition, in cultured granulosa cells, high testosterone concentrations induced cell proliferation, and increased the mRNA expression level of FSH receptor (FSHR), and luteinized hormone/choriogonadotropin receptor. It was concluded that high concentrations of testosterone inhibited follicle development, most likely through regulation of the FSH signaling pathway, although independently from FSHR downregulation. These findings are an important step in further understanding the pathogenesis of polycystic ovary syndrome.

Effect of gestational antiandrogen treatment on Dicer1 expression in the porcine fetal gonads

Recently, we have demonstrated that flutamide-induced androgen deficiency during fetal life led to changes in gene expression that affected both testicular functions and follicular formation. It is known that microRNA-mediated genes regulation is essential for gonadal development and function. Thus, the aim of the present study was to examine whether prenatal flutamide exposure influences expression of Dicer1, an enzyme involved in microRNA maturation, in gonads of porcine fetuses during mid- and late gestation. Pregnant gilts were injected with flutamide (50mg/day/kg b.w.) or corn oil (controls) between days 43-49, 83-89 or 101-107 of gestation. The fetal gonads were obtained on gestational day 50 (GD50), 90 (GD90) or 108 (GD108). To assess Dicer1 mRNA expression real-time PCR were performed. Furthermore, immunohistochemical Dicer1 localization was conducted. In testes from flutamide treated fetuses, increased Dicer1 mRNA expression was observed in the GD50 and GD108 groups, but decreased in the GD90 group. Dicer1 was immunolocalized in the fetal Leydig cells in both control and flutamide-treated groups. In fetal ovaries, antiandrogen treatment increased Dicer1 mRNA level in the GD50 and GD90 groups. In control and flutamide-exposed groups, Dicer1 was localized in the germ cells within oogonia/oocyte nests as well as in the granulosa cells and oocytes of forming follicles. Concluding, diminished androgen action during gestation induces changes in Dicer1 mRNA expression, which may affect post-transcriptional gene regulation via miRNAs in porcine fetal gonads. However, it seems that androgens exert diverse biological effects depending on the gestational period.

Caloric restriction increases ratio of estrogen to androgen receptors expression in murine ovaries--potential therapeutic implications

Both estrogens and androgens are involved in the development and normal functioning of the ovaries. It is also known that ovarian function is regulated by diet. The goal of this study was to estimate the expression of sex hormone receptors in ovaries of mice that were on a 9-month caloric restriction (alternate-day feeding) as compared to normal control animals fed ad libitum. We found that prolonged caloric restriction in mouse ovaries led to increased expression of estrogen receptors (ERs) but did not affect expression of the androgen receptor (AR). This increase in ER:AR ration as result of caloric restriction may lead to higher sensitivity to estrogens and upon return to normal diet may increase ovulation. Thus our observation shed more light on a role of beneficial effect of calorie restriction on female reproduction.

A Flexible Multidose GnRH Antagonist versus a Microdose Flare-Up GnRH Agonist Combined with a Flexible Multidose GnRH Antagonist Protocol in Poor Responders to IVF

Objective. To compare the effectiveness of a flexible multidose gonadotropin-releasing hormone (GnRH) antagonist against the effectiveness of a microdose flare-up GnRH agonist combined with a flexible multidose GnRH antagonist protocol in poor responders to in vitro fertilization (IVF). Study Design. A retrospective study in Akdeniz University, Faculty of Medicine, Department of Obstetrics and Gynecology, IVF Center, for 131 poor responders in the intracytoplasmic sperm injection-embryo transfer (ICSI-ET) program between January 2006 and November 2012. The groups were compared to the patients' characteristics, controlled ovarian stimulation (COH) results, and laboratory results. Results. Combination protocol was applied to 46 patients (group 1), and a single protocol was applied to 85 patients (group 2). In group 1, the duration of the treatment was longer and the dose of FSH was higher. The cycle cancellation rate was significantly higher in group 2 (26.1% versus 38.8%). A significant difference was not observed with respect to the number and quality of oocytes and embryos or to the number of embryos transferred. There were no statistically significant differences in the hCG positivity (9.5% versus 9.4%) or the clinical pregnancy rates (7.1% versus 10.6%). Conclusion. The combination protocol does not provide additional efficacy.

Dynamics of the ovarian reserve and impact of genetic and epidemiological factors on age of menopause

The narrow standard age range of menopause, ∼50 yr, belies the complex balance of forces that govern the underlying formation and progressive loss of ovarian follicles (the "ovarian reserve" whose size determines the age of menopause). We show here the first quantitative graph of follicle numbers, distinguished from oocyte counts, across the reproductive lifespan, and review the current state of information about genetic and epidemiological risk factors in relation to possible preservation of reproductive capacity. In addition to structural X-chromosome changes, several genes involved in the process of follicle formation and/or maintenance are implicated in Mendelian inherited primary ovarian insufficiency (POI), with menopause before age 40. Furthermore, variants in a largely distinct cohort of reported genes-notably involved in pathways relevant to atresia, including DNA repair and cell death-have shown smaller but additive effects on the variation in timing of menopause in the normal range, early menopause (age <45), and POI. Epidemiological factors show effect sizes comparable to those of genetic factors, with smoking accounting for about 5% of the risk of early menopause, equivalent to the summed effect of the top 17 genetic variants. The identified genetic and epidemiological factors underline the importance of early detection of reproductive problems to enhance possible interventions.