Optimizing ovulation induction in women with polycystic ovary syndrome

Emerging follicular activation strategies to treat women with poor ovarian response and primary ovarian insufficiency

PURPOSE OF THE REVIEW

Female reproductive aging remains one of the key unsolved challenges in the field of reproductive medicine. This article reviews three of the most recent and cutting-edge strategies that are currently being investigated to address the issues of poor ovarian response (POR) and primary ovarian insufficiency (POI).

RECENT FINDINGS

Publications revealing the mechanism of mechanical disruption of the Hippo signaling pathway paved the way to studies on its potential application for fertility treatments. This, in combination with Akt stimulation, resulted in live births and ongoing pregnancies in women with POI. Building on previous reports on the effects of bone marrow transplants on fertility after chemotherapy, another approach involved autologous stem cell ovarian transplantation (ASCOT). The method proved effective in achieving live births in women previously diagnosed with POR. A third approach, intraovarian injection of autologous platelet-rich plasma, resulted in live births and ongoing pregnancies both spontaneously and via in vitro fertilization (IVF) in women with POI and POR.

SUMMARY

New paths are being charted to address the issues of POI and POR. Although these are preliminary studies that should be interpreted with caution, they represent great promise for the women affected by these conditions and the physicians treating them.

MIF May Participate in Pathogenesis of Polycystic Ovary Syndrome in Rats through MAPK Signalling Pathway

The polycystic ovary syndrome (PCOS) model was established in rats and correlation between the expression of macrophage migration inhibitory factor (MIF) and cytokinesis with the MAPK signalling pathway in the rat ovary was measured. The PCOS model in rats was established by dehydroepiandrosterone (DHEA). Thirty sexually immature female Sprague-Dawley rats were randomly and equally assigned to three groups: control group, PCOS group, and PCOS with high-fat diet (HFD) group. Serum hormones were assayed by radioimmunoassay (RIA). The ovaries were immunohistochemically stained with MIF, and the expression of MIF, p-JNK and p-p38 was detected by Western blotting in ovaries. The serum testosterone level, LH concentration, LH/FSH ratio, fasting insulin level and HOMA IR index in the PCOS group (6.077±0.478, 13.809±1.701, 1.820±0.404, 10.83±1.123 and 1.8692±0.1096) and PCOS with HFD group (6.075±0.439, 14.075±1.927, 1.779±0.277, 10.20±1.377 and 1.7736±0.6851) were significantly higher than those in the control group (4.949±0.337, 2.458±0.509, 1.239±0.038, 9.53±0.548 and 1.5329±0.7363), but there was no significant difference between the PCOS group and PCOS with HFD group. The expression levels of MIF, p-JNK, and p-p38 in the PCOS group (0.4048±0.013, 0.6233±0.093 and 0.7987±0.061) and PCOS with HFD group (0.1929±0.012, 0.3346±0.103 and 0.3468±0.031) were obviously higher than those in control group (0.2492±0.013, 0.3271±0.093 and 0.3393±0.061), but no significant difference was observed between PCOS group and PCOS with HFD group. It was suggested that MIF may participate in the pathogenesis of PCOS through the MAPK signalling pathway in PCOS rats induced by DHEA.

Update in polycystic ovary syndrome: new criteria of diagnosis and treatment in Japan

Polycystic ovary syndrome (PCOS) is the most frequent endocrine disorder in women of reproductive age. In 2006 the Japanese Society of Obstetrics and Gynecology (JSOG) proposed new, revised diagnostic criteria that in the future could also be valued internationally. Based on the new diagnostic criteria, the JSOG has also proposed the revised treatment criteria in 2008. In PCOS obese patients desiring children, weight loss and exercise is recommended. Nonobese patients, or those obese women who do not ovulate after lifestyle changes, are submitted to ovulation-induction therapy with clomiphene citrate (CC). Obese CC-resistant patients who have impaired glucose tolerance or insulin resistance are treated with a combination of metformin and CC. If these treatments options are unsuccessful, ovulation induction with exogenous gonadotropin therapy or laparoscopic ovarian drilling (LOD) is recommended. A low-dose step-up regimen is recommended with careful monitoring in order to reduce the risk of ovarian hyperstimulation syndrome (OHSS) and multiple pregnancies. Alternatively, with LOD high successful pregnancy rates of around 60 % are expected with a low risk of multiple pregnancies. If ovulation induction is unsuccessful, IVF-ET treatment is indicated. In high OHSS-risk patients, systematic embryo freezing and subsequent frozen embryo transfer cycles are recommended. In nonobese, anovulatory PCOS patients not desiring children, pharmacological treatments such as Holmström, Kaufmann regimens or low-dose oral anticonceptives are used to induce regular withdrawal bleeding. These treatments are especially important for preventing endometrial hyperplasia and endometrial cancer. These new diagnostic and treatment criteria hopefully will contribute to an improved care of PCOS patients in Japan.

Weight loss before conception: A systematic literature review

The prevalence of overweight and obesity in women has increased during the last decades. This is a serious concern since a high BMI before conception is an independent risk factor for many adverse outcomes of pregnancy. Therefore, dietary counseling, intended to stimulate weight loss in overweight and obese women prior to conception has recently been recommended. However, dieting with the purpose to lose weight may involve health risks for mother and offspring. We conducted a systematic literature review to identify papers investigating the effects of weight loss due to dietary interventions before conception. The objective of this study is to assess the effect of weight loss prior to conception in overweight or obese women on a number of health-related outcomes in mother and offspring using studies published between January 2000 and December 2011. Our first literature search produced 486 citations and, based on predefined eligibility criteria, 58 were selected and ordered in full text. Two group members read each paper. Fifteen studies were selected for quality assessment and two of them were considered appropriate for inclusion in evidence tables. A complementary search identified 168 citations with four papers being ordered in full text. The two selected studies provided data for overweight and obese women. One showed a positive effect of weight loss before pregnancy on the risk of gestational diabetes and one demonstrated a reduced risk for large-for-gestational-age infants in women with a BMI above 25 who lost weight before pregnancy. No study investigated the effect of weight loss due to a dietary intervention before conception. There is a lack of studies on overweight and obese women investigating the effect of dietary-induced weight loss prior to conception on health-related variables in mother and offspring. Such studies are probably lacking since they are difficult to conduct. Therefore, alternative strategies to control the body weight of girls and women of reproductive age are needed.

PPARs and Female Reproduction: Evidence from Genetically Manipulated Mice

Peroxisome proliferator-activated receptors (PPARs) are ligand-activated nuclear receptors controlling many important physiological processes, including lipid and glucose metabolism, energy homeostasis, inflammation, as well as cell proliferation and differentiation. In the past decade, intensive study of PPARs has shed novel insight into prevention and treatment of dyslipidemia, insulin resistance, and type 2 diabetes. Recently, a large body of research revealed that PPARs are also functionally expressed in reproductive organs and various parts of placenta during pregnancy, which strongly suggests that PPARs might play a critical role in reproduction and development, in addition to their central actions in energy homeostasis. In this review, we summarize recent findings elucidating the role of PPARs in female reproduction, with particular focus on evidence from gene knockout and transgenic animal model study.

Peroxisome proliferator-activated receptor (PPAR)gamma is expressed by human spermatozoa: its potential role on the sperm physiology

The peroxisome proliferation-activated receptor gamma (PPARgamma) is mainly expressed in the adipose tissue and integrates the control of energy, lipid, and glucose homeostasis. The present study, by means of RT-PCR, Western blot, and immunofluorescence techniques, demonstrates that human sperm express the PPARgamma. The functionality of the receptor was evidenced by 15-deoxy-12,14-prostaglandin J(2) (PGJ2) and rosiglitazone (BRL) PPARgamma-agonists that were tested on capacitation, acrosome reaction, and motility. Both treatments also increase AKT phosphorylations and influence glucose and lipid metabolism in sperm. The specificity of PGJ2 and BRL effects through PPARgamma on human sperm was confirmed by an irreversible PPARgamma antagonist, GW9662. Our findings provide evidence that human sperm express a functional PPARgamma whose activation influences sperm physiology. In conclusion, the presence of PPARgamma in male gamete broadens the field of action of this nuclear receptor, bringing us to look towards sperm as an endocrine mobile unit independent of the systemic regulation.

Prognostic factors for ovulatory response with clomiphene citrate in polycystic ovary syndrome

OBJECTIVE

To evaluate prospectively the prognostic factors for ovulatory responses following clomiphene citrate (CC) administration in polycystic ovary syndrome (PCOS).

STUDY DESIGN

Fifty-nine infertile patients with a diagnosis of PCOS were recruited. Ovulation was induced using 100 mg/day CC administered daily from days 5 to 9 of the cycle. Endocrine and metabolic parameters between responder and non-responder groups were analyzed.

RESULTS

For a 75-g fasting glucose load (75-g OGTT), blood glucose levels at 60 and 120 min, the area under the curve (AUC) and blood insulin levels at 120 min in the non-responder group (n=25) were significantly higher than those in the responder group (n=34), although the measurements of fasting blood glucose and insulin were not significantly different between the two groups. In the receiver operating characteristic curves, the most appropriate cutoff point was 120 mg/dl for the blood glucose level at 120 min and 9000 for the blood glucose x insulin level at 120 min. There were no significant differences in the clinical characteristics or in the endocrine and metabolic parameters between conceived (n=9) and non-conceived groups (n=21).

CONCLUSION

The levels of blood glucose and blood glucose x insulin at 120 min after 75-g OGTT could be good biochemical markers of CC resistance in PCOS. No predictors of conception following CC therapy were identified by this study.

Higher basal adiponectin levels are associated with better ovarian response to gonadotropin stimulation during in vitro fertilization

AIMS

To measure adiponectin levels in the serum samples from day 3 of the menstrual cycle prior to the administration of gonadotropin during in vitro fertilization, and to measure any correlations between adiponectin levels and the number of oocytes retrieved, body weights and body mass indexes. Also, to examine whether there is a difference in adiponectin levels between women who conceive and those who do not.

METHODS

In a case-control design, 56 women undergoing in vitro fertilization procedures were included in this study: 28 women who conceived were matched with 28 women who did not conceive. Adiponectin levels in serum were determined by radioimmunoassay and compared.

RESULTS

The adiponectin levels were positively correlated with the number of oocytes retrieved (r = 0.306, p = 0.022), but negatively correlated with body mass index and body weight (r = -0.367, p = 0.005; r = -0.326, p = 0.014). No significant correlations were found between the number of oocytes retrieved and body mass index or body weight (r = 0.020, p = 0.882; r = 0.069, p = 0.613). We further observed that adiponectin levels in women who conceived (23.0 +/- 2.0 microg/ml) were found to be significantly higher (p = 0.026) than those in women who did not conceive (17.3 +/-1.4 microg/ml). The number of oocytes retrieved from women who conceived (13.3 +/- 0.9) was also higher than that in women who did not (10 +/- 1.2; p = 0.029).

CONCLUSIONS

The number of oocytes retrieved was found to correlate positively with the adiponectin levels on the day prior to the administration of gonadotropin. In addition, basal adiponectin levels were significantly higher in those women who conceived. Therefore, adiponectin is a better marker of adequate follicular development during in vitro fertilization than is body weight or body mass index.

Effects of low-dose metformin in Japanese women with clomiphene-resistant polycystic ovary syndrome

Background and Aims:  The aim of the present prospective observational study was to evaluate the effects of low-dose, short-term metformin, in combination with clomiphene (CC), in CC-resistant infertile Japanese women with polycystic ovary syndrome (PCOS). Methods:  Metformin therapy was administered orally (one 250 mg tablet, twice daily) to 15 CC-resistant infertile patients with PCOS, beginning on the third day of progestin-induced withdrawal bleeding, and was continued for 14 days in the first cycle. In the event of anovulation, 100 mg/day of CC was given during subsequent cycles on days 5-9, in addition to the aforementioned dose of metformin. Hormonal and metabolic parameters were measured on the second or third days of the first cycle and also the fourth cycle, following an overnight fast. Results:  None of the 15 women successfully ovulated during the first cycle with metformin treatment alone. After two subsequent cycles with the combination of CC and metformin, ovulation was confirmed in 17 of 29 cycles (61%) and in 13 of 15 patients (87%). Two women became pregnant within 2 months of therapy (13%). There were no cases of ovarian hyperstimulation syndrome. Following three cycles of metformin therapy, a slight reduction in serum levels of luteinizing hormone (LH), free testosterone, androstenedione, dehydroepiandrosterone sulfate, hemoglobin A1c and total cholesterol was seen, while serum LH/follicle-stimulating hormone ratio and serum level of low-density lipoprotein cholesterol were significantly decreased. Although there were no significant differences between the responder (n = 11) and non-responder (n = 2) groups at baseline, the levels of plasma fasting insulin was significantly higher and fasting glucose/insulin ratio was significantly lower in the non-responder group compared with the responder group after three cycles. Conclusion:  Low-dose, short-term metformin, combined with CC, can improve ovulation rates in CC-resistant infertile Japanese women with PCOS. (Reprod Med Biol 2004; 3: 19-26).

A systematic review of the reproductive system effects of metformin in patients with polycystic ovary syndrome

OBJECTIVE

To review the effectiveness of metformin in restoring regular menstrual cycles and ovulation and achieving pregnancy in women with polycystic ovary syndrome (PCOS).

DESIGN

Systematic review of pertinent studies identified using the bibliographic databases MEDLINE and EMBASE. References of selected articles identified were hand-searched for additional relevant citations.

PATIENT(S)

Women with PCOS undergoing treatment with metformin alone, metformin combined with other methods of ovulation induction such as clomiphene citrate (CC) or gonadotropin injections, or metformin combined with in vitro fertilization (IVF).

RESULT(S)

Thirty published studies were included in the overall review. Studies consisted of 12 randomized controlled trials, two cohort studies, and 16 uncontrolled descriptive studies. Due to a strong variability in the use of metformin according to study population, exposure, and outcome of interest, it was not possible to combine the data of the 12 randomized controlled trials to perform a meta-analysis. Limited data on predominately obese PCOS patients demonstrate that metformin alone improves both restoration of regular menses and spontaneous ovulation, but there are no data supporting an improvement in pregnancy rate. The addition of metformin to CC results in an improved ovulation and pregnancy rate in both unselected and CC-resistant PCOS women. There are insufficient data to make any conclusions on the effect of metformin on FSH ovulation induction or IVF.

CONCLUSION(S)

The effectiveness and role of metformin in the treatment of PCOS anovulatory infertility in clinical practice is difficult to assess from currently available research. Further well-designed prospective, perhaps multicenter, randomized controlled trials with the primary end point of pregnancy or live-birth rate are required.