Does metformin affect the ovarian response to gonadotropins for in vitro fertilization treatment in patients with polycystic ovary syndrome and reduced ovarian reserve? A randomized controlled trial

Assessing ovarian stimulation with letrozole and levonorgestrel intrauterine system after combined fertility-sparing approach for atypical endometrial lesions: a retrospective case-control study

RESEARCH QUESTION

Is ovarian stimulation with levonorgestrel intrauterine system (LNG-IUS) in situ and co-treatment with letrozole safe and effective in patients undergoing fertility-sparing combined treatment for atypical endometrial hyperplasia (AEH) or early endometrial cancer limited to the endometrium?

DESIGN

Retrospective case-control study recruiting women who had undergone fertility-sparing 'combined' treatment and ovarian stimulation with letrozole and LNG-IUS in situ. The 'three steps' hysteroscopic technique was used. Once complete response was achieved, the ovaries were stimulated, and mature oocytes cryopreserved. The LNG-IUS was removed, and embryos transferred. A comparative analysis was conducted between the two control groups of the initial outcomes of ART (number of oocytes and MII oocytes retrieved): healthy infertile women undergoing ovarian stimulation for IVF/ICSI (control group A); and patients diagnosed with breast cancer who underwent ovarian stimulation with letrozole (control group B).

RESULTS

Of the 75 patients analysed, 15 underwent oocyte cryopreservation after achieving a complete response to fertility-sparing treatment (study group); 30 patients in control group A and B, respectively. No statistically significant differences were observed in retrieved oocytes and mature oocytes between the study and control groups. In the nine patients who underwent embryo transfer, clinical pregnancy (55.6%), cumulative live birth (44.4%) and miscarriage (20%) rates were reported. In three patients with AEH, recurrence occurred (12%) at 3, 6 and 16 months after removing the LNG-IUS to attempt embryo transfer, respectively.

CONCLUSION

Fertility-sparing hysteroscopic combined treatment and subsequent ovarian stimulation with letrozole and LNG-IUS in situ could be suggested to women with AEH or early endometrial cancer who ask for future fertility preservation.

Myo-Inositol and D-Chiro-Inositol as Modulators of Ovary Steroidogenesis: A Narrative Review

Myo-inositol is a natural polyol, the most abundant among the nine possible structural isomers available in living organisms. Inositol confers some distinctive traits that allow for a striking distinction between prokaryotes and eukaryotes, the basic clusters into which organisms are partitioned. Inositol cooperates in numerous biological functions where the polyol participates or by furnishing the fundamental backbone of several related derived metabolites, mostly obtained through the sequential addition of phosphate groups (inositol phosphates, phosphoinositides, and pyrophosphates). Overall myo-inositol and its phosphate metabolites display an entangled network, which is involved in the core of the biochemical processes governing critical transitions inside cells. Noticeably, experimental data have shown that myo-inositol and its most relevant epimer D-chiro-inositol are both necessary to permit a faithful transduction of insulin and of other molecular factors. This improves the complete breakdown of glucose through the citric acid cycle, especially in glucose-greedy tissues, such as the ovary. In particular, while D-chiro-inositol promotes androgen synthesis in the theca layer and down-regulates aromatase and estrogen expression in granulosa cells, myo-inositol strengthens aromatase and FSH receptor expression. Inositol effects on glucose metabolism and steroid hormone synthesis represent an intriguing area of investigation, as recent results have demonstrated that inositol-related metabolites dramatically modulate the expression of several genes. Conversely, treatments including myo-inositol and its isomers have proven to be effective in the management and symptomatic relief of a number of diseases associated with the endocrine function of the ovary, namely polycystic ovarian syndrome.

The Role of Inositols in the Hyperandrogenic Phenotypes of PCOS: A Re-Reading of Larner’s Results

Polycystic ovarian syndrome (PCOS) is the most common endocrinological disorder in women, in which, besides chronic anovulation/oligomenorrhea and ovarian cysts, hyperandrogenism plays a critical role in a large fraction of subjects. Inositol isomers—myo-Inositol and D-Chiro-Inositol—have recently been pharmacologically effective in managing many PCOS symptoms while rescuing ovarian fertility. However, some disappointing clinical results prompted the reconsideration of their specific biological functions. Surprisingly, D-Chiro-Ins stimulates androgen synthesis and decreases the ovarian estrogen pathway; on the contrary, myo-Ins activates FSH response and aromatase activity, finally mitigating ovarian hyperandrogenism. However, when the two isomers are given in association—according to the physiological ratio of 40:1—patients could benefit from myo-Ins enhanced FSH and estrogen responsiveness, while taking advantage of the insulin-sensitizing effects displayed mostly by D-Chiro-Ins. We need not postulate insulin resistance to explain PCOS pathogenesis, given that insulin hypersensitivity is likely a shared feature of PCOS ovaries. Indeed, even in the presence of physiological insulin stimulation, the PCOS ovary synthesizes D-Chiro-Ins four times more than that measured in control theca cells. The increased D-Chiro-Ins within the ovary is detrimental in preserving steroidogenic control, and this failure can easily explain why treatment strategies based upon high D-Chiro-Ins have been recognized as poorly effective. Within this perspective, two factors emerge as major determinants in PCOS: hyperandrogenism and reduced aromatase expression. Therefore, PCOS could no longer be considered a disease only due to increased androgen synthesis without considering the contemporary downregulation of aromatase and FSH receptors. Furthermore, these findings suggest that inositols can be specifically effective only for those PCOS phenotypes featured by hyperandrogenism.

Metformin: new applications for an old drug

Metformin is a biguanide, evolved as one of the most widely used medicines. The applications of this component include but are not limited to reducing blood glucose, weight loss, and polycystic ovary syndrome. Studies about other probable indications have emerged, indicating that this agent can also be utilized for other purposes. In this review, applications of metformin are noticed based on the current evidence. Metformin commonly is used as an off-label drug in non-alcoholic fatty liver disease (NAFLD), but it worsens inflammation and should not be used for this purpose, according to the latest research. Metformin decreased the risk of death in patients with liver cirrhosis. It is an effective agent in the prevention and improvement of survival in patients suffering hepatocellular carcinoma. There is evidence of the beneficial effects of metformin in colorectal cancer, early-stage prostate cancer, breast cancer, urothelial cancer, blood cancer, melanoma, and bone cancer, suggesting metformin as a potent anti-tumor agent. Metformin shows neuroprotective effects and provides a potential therapeutic benefit for mild cognitive impairment and Alzheimer's disease (AD). It also has been shown to improve mental function and reduce the incidence of dementia. Another condition that metformin has been shown to slow the progression of is Duchenne muscular dystrophy. Regarding infectious diseases, tuberculosis (TB) and coronavirus disease (COVID-19) are among the conditions suggested to be affected by metformin. The beneficial effects of metformin in cardiovascular diseases were also reported in the literature. Concerning renal function, studies showed that daily oral administration of metformin could ameliorate kidney fibrosis and normalize kidney structure and function. This study reviewed the clinical and preclinical evidence about the possible benefits of metformin based on recent studies. Numerous questions like whether these probable indications of metformin can be observed in non-diabetics, need to be described by future basic experiments and clinical studies.

Effectiveness of inositol, metformin and their combination in women with PCOS undergoing assisted reproduction: systematic review and meta-analysis

OBJECTIVE

Our study aims to compare the effect of metformin, inositol and their combinations on the efficiency in improving outcomes of assisted reproductive technologies in women with PCOS.

DATA SOURCES

PubMed, The Cochrane Library, ClinicalTrials.gov, Embase, MEDLINE. The search was performed on studies published before November 14, 2021, to identify articles evaluating the effectiveness of treatment metformin and inositol on ART outcomes.

STUDY SELECTION

The systematic review was conducted according to the PRISMA 2020 checklist and registered in the PROSPERO 2021 CRD42021287887. Randomized controlled trials (RCTs) in English that compared metformin or inositol or metformin + inositol treatment with placebo or no treatment in women with PCOS undergoing assisted reproduction were included. In addition, RCTs with comparison combination and single metformin or inositol treatment were also included.

DATA EXTRACTION AND SYNTHESIS

35 RCTs were included for qualitative analysis reporting on 4668 participants. In group of Metformin treatment were included 1891 patients, in Myo-inositol group - 281, in inositol + metformin group were included 110 participants and in control group (placebo or absence of treatment) - 1865 women with PCOS. 5 meta-analyses were performed. CPR in comparison of metformin and placebo in 1312 patients were higher in metformin group (RR = 1.30, 95% CI: 1.12 to 1.50, p = 0.0004). OHSS was less in metformin (RR = 0.34, 95% CI: 0.17 to 0.69, p = 0.003). However, LBR were not statistically significant (RR = 1.12, 95% CI: 0.93 to 1.36, p = 0.24). In comparison of inositol and no treatment there was also no difference in CPR (RR = 1.37, 95% CI: 0.79 to 2.38, p = 0.26). As for metformin and inositol meta-analysis in 220 patients with PCOS, CPR were higher in inositol group (RR = 1.52, 95% CI: 1.05 to 2.18, p = 0.03). Combination treatment included only two RCTs and was illegible for meta-analysis.

CONCLUSION

To our knowledge, it is the first meta-analysis that estimates inositol treatment compared to metformin. Based on our systematic review and meta-analysis, metformin seems to be a good option for improving ART outcomes in women with PCOS. However, it is not clear whether inositol usage is adequate. Nevertheless, we need more clinical trials of good quality to answer all questions thoroughly.

Metformin treatment before and during IVF or ICSI in women with polycystic ovary syndrome

BACKGROUND

The use of insulin-sensitising agents, such as metformin, in women with polycystic ovary syndrome (PCOS) who are undergoing ovulation induction or in vitro fertilisation (IVF) cycles has been widely studied. Metformin reduces hyperinsulinaemia and suppresses the excessive ovarian production of androgens. It is suggested that as a consequence metformin could improve assisted reproductive techniques (ART) outcomes, such as ovarian hyperstimulation syndrome (OHSS), pregnancy, and live birth rates.

OBJECTIVES

To determine the effectiveness and safety of metformin as a co-treatment during IVF or intracytoplasmic sperm injection (ICSI) in achieving pregnancy or live birth in women with PCOS.

SEARCH METHODS

We searched the Cochrane Gynaecology and Fertility Group Specialised Register, CENTRAL via the Cochrane Register of Studies Online (CRSO), MEDLINE, Embase, PsycINFO, LILACS, the trial registries for ongoing trials, and reference lists of articles (from inception to 13 February 2020).

SELECTION CRITERIA

Types of studies: randomised controlled trials (RCTs) comparing metformin treatment with placebo or no treatment in women with PCOS who underwent IVF or ICSI treatment.

TYPES OF PARTICIPANTS

women of reproductive age with anovulation due to PCOS with or without co-existing infertility factors. Types of interventions: metformin administered before and during IVF or ICSI treatment.

PRIMARY OUTCOME MEASURES

live birth rate, incidence of ovarian hyperstimulation syndrome.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected the studies, extracted the data according to the protocol, and assessed study quality. We assessed the overall quality of the evidence using the GRADE approach.

MAIN RESULTS

This updated review includes 13 RCTs involving a total of 1132 women with PCOS undergoing IVF/ICSI treatments. We stratified the analysis by type of ovarian stimulation protocol used (long gonadotrophin-releasing hormone agonist (GnRH-agonist) or short gonadotrophin-releasing hormone antagonist (GnRH-antagonist)) to determine whether the type of stimulation used influenced the outcomes. We did not perform meta-analysis on the overall (both ovarian stimulation protocols combined) data for the outcomes of live birth and clinical pregnancy rates per woman because of substantial heterogeneity. In the long protocol GnRH-agonist subgroup, the pooled evidence showed that we are uncertain of the effect of metformin on live birth rate per woman when compared with placebo/no treatment (risk ratio (RR) 1.30, 95% confidence interval (CI) 0.94 to 1.79; 6 RCTs; 651 women; I2 = 47%; low-quality evidence). This suggests that if the chance for live birth following placebo/no treatment is 28%, the chance following metformin would be between 27% and 51%. Only one study used short protocol GnRH-antagonist and reported live birth rate. Metformin may reduce live birth rate compared with placebo/no treatment (RR 0.48, 95% CI 0.29 to 0.79; 1 RCT; 153 women; low-quality evidence). This suggests that if the chance for live birth following placebo/no treatment is 43%, the chance following metformin would be between 13% and 34% (short GnRH-antagonist protocol). We found that metformin may reduce the incidence of OHSS (RR 0.46, 95% CI 0.29 to 0.72; 11 RCTs; 1091 women; I2 = 38%; low-quality evidence). This suggests that for a woman with a 20% risk of OHSS without metformin, the corresponding risk using metformin would be between 6% and 14%. Using long protocol GnRH-agonist stimulation, metformin may increase clinical pregnancy rate per woman compared with placebo/no treatment (RR 1.32, 95% CI 1.08 to 1.63; 10 RCTs; 915 women; I2 = 13%; low-quality evidence). Using short protocol GnRH-antagonist, we are uncertain of the effect of metformin on clinical pregnancy rate per woman compared with placebo/no treatment (RR 1.38, 95% CI 0.21 to 9.14; 2 RCTs; 177 women; I2 = 87%; very low-quality evidence). We are uncertain of the effect of metformin on miscarriage rate per woman when compared with placebo/no treatment (RR 0.86, 95% CI 0.56 to 1.32; 8 RCTs; 821 women; I2 = 0%; low-quality evidence). Metformin may result in an increase in side effects compared with placebo/no treatment (RR 3.35, 95% CI 2.34 to 4.79; 8 RCTs; 748 women; I2 = 0%; low-quality evidence). The overall quality of evidence ranged from very low to low. The main limitations were inconsistency, risk of bias, and imprecision.

AUTHORS' CONCLUSIONS

This updated review on metformin versus placebo/no treatment before or during IVF/ICSI treatment in women with PCOS found no conclusive evidence that metformin improves live birth rates. In a long GnRH-agonist protocol, we are uncertain whether metformin improves live birth rates, but metformin may increase the clinical pregnancy rate. In a short GnRH-antagonist protocol, metformin may reduce live birth rates, although we are uncertain about the effect of metformin on clinical pregnancy rate. Metformin may reduce the incidence of OHSS but may result in a higher incidence of side effects. We are uncertain of the effect of metformin on miscarriage rate per woman.

Infertility and physical activity: A cross-sectional study of women living in Yazd aged 20-49 yr, 2014-2015

Background

Changes in the state of energy balance owing to changes in physical activity (PA) may affect the reproductive system.

Objective

the aim of this study was to assess the association between PA and infertility of women living in Yazd 2014 - 2015.

Materials and Methods

The study method was analytical cross-sectional on the Yazd Health Study (YaHS) data which was conducted on 10,000 people. We studied 2,611 women (20 and 49 yrs old), living in Greater Yazd area. PA information was collected using a physical activity questionnaire (IPAQ) short form. The standardized instruments were used for anthropometrics measurement.

Results

Totally 135 cases of infertility were documented. The overall prevalence of infertility was 4.73% (95% CI: 3.94-5.59%). The median of PA scores (METs) in women was 746.66 and 25-75% interquartile range was 361.25-1277.25. The relationship according to the Chi-square test between infertility and PA, as categorized variables, was significant (p = 0.015). It showed over 90% of those who suffered from infertility had a low or moderate PA.

Conclusion

The results of our study showed that there is a significant relationship between infertility and PA level in women living in Greater Yazd area. Also, women with infertility had lower activity levels, consistent with most previous studies.

Association of Metformin With Pregnancy Outcomes in Women With Polycystic Ovarian Syndrome Undergoing In Vitro Fertilization: A Systematic Review and Meta-analysis

IMPORTANCE

Metformin is widely used among women with polycystic ovary syndrome (PCOS). However, its associations with outcomes of in vitro fertilization or intracytoplasmic sperm injection and embryo transfer (IVF/ICSI-ET) in women with PCOS remain controversial.

OBJECTIVE

To assess whether metformin is associated with improved outcomes of IVF/ICSI-ET in women with PCOS.

DATA SOURCES

PubMed, Embase, and Cochrane were searched from database inception to January 31, 2020.

STUDY SELECTION

Only randomized clinical trials (RCTs) were included. Eligible studies enrolled women with PCOS undergoing infertility treatment with IVF/ICSI-ET and reported at least 1 outcome of IVF/ICSI-ET.

DATA EXTRACTION AND SYNTHESIS

This study followed the Preferred Reporting Items for Systematic Reviews and Meta analyses guidelines. Two authors independently extracted the data. Study quality was evaluated using the GRADE system. Treatment effect was quantified using odds ratios (ORs) with 95% CIs using random-effect models with the Mantel-Haenszel method.

MAIN OUTCOMES AND MEASURES

Ovarian hyperstimulation syndrome (OHSS), clinical pregnancy rate, and live birth rate.

RESULTS

A total of 12 RCTs, which collectively included 1123 women with PCOS undergoing infertility treatment with IVF/ICSI-ET, were identified. The risk of OHSS in women randomized to metformin was lower than in women not randomized to metformin (OR, 0.43; 95% CI, 0.24-0.78), although this difference was not significant for women with PCOS with a body mass index of less than 26 (OR, 0.67; 95% CI, 0.30-1.51). There was no significant difference in clinical pregnancy rate (OR, 1.24; 95% CI, 0.82-1.86) or live birth rate (OR, 1.23; 95% CI, 0.74-2.04) in the total population studied. However, in a post hoc analysis among women with a body mass index of 26 or greater, metformin treatment was associated with increased clinical pregnancy rates (OR, 1.71; 95% CI, 1.12-2.60).

CONCLUSIONS AND RELEVANCE

In this study, metformin treatment was associated with a decreased risk of OHSS but had no association with the overall clinical pregnancy rate or live birth rate among women with PCOS undergoing IVF/ICSI-ET. Metformin treatment should be carefully considered for women with PCOS undergoing IVF/ICSI-ET and may be more preferred for women with a body mass index greater than 26.

Transvaginal ovarian drilling followed by controlled ovarian stimulation from the next day improves ovarian response for the poor responders with polycystic ovary syndrome during IVF treatment: a pilot study

BACKGROUND

Poor response patients with PCOS who are not susceptible to gonadotropin stimulation are more likely to have canceled cycles or poor clinical outcomes during IVF treatment. However, some limitations exist in the present therapies. In this study, we evaluated the effects of using the transvaginal ovarian drilling (TVOD) followed by controlled ovarian stimulation (COS) from the second day of these poor responders.

METHODS

During IVF, 7 poor responders with PCOS and 28 PCOS patients (14 normal and 14 high responders) were recruited. All patients received COS with the gonadotropin-releasing hormone antagonist protocol. For the poor responders, after undergoing 10 to 14 days of ovulation induction with no response, the TVOD was applied and then ovarian stimulation was performed from the next day at the same gonadotropin dose. Serum samples during COS and follicular fluid samples from the dominant follicles on the oocyte pick-up (OPU) day in all three groups were collected. Besides, follicular fluid from small follicles (diameter < 1 cm) in the normal and high responders on the OPU day and those in the poor responders on the TVOD day were gathered. Hormonal levels were examined in all samples using immunometric assays.

RESULTS

All the poor responders restored ovary response after receiving TVOD. There was no significant difference in the stimulation duration, total gonadotrophin dose used and the clinical outcomes among the three groups. The body mass index, serum and follicular levels of anti-Müllerian hormone (AMH) and testosterone in poor responders were higher than those in the other two groups, and the application of TVOD significantly decreased the levels of AMH and testosterone in both serum and follicular fluid.

CONCLUSIONS

TVOD followed by ovulation induction from the next day is effective and convenient for poor responders with PCOS. The decline of AMH and testosterone resulted from TVOD may be the main reason resulting in the recovery of ovary sensitivity to gonadotropins. The small sample size is the primary limitation of this study, future studies using a large population cohort and monitoring the long-term outcomes of this strategy will be required.

TRIAL REGISTRATION

ChiCTR1900023612. Registered 04 June 2019-Retrospectively registered.

Impact of Metformin on IVF Outcomes in Overweight and Obese Women With Polycystic Ovary Syndrome: A Randomized Double-Blind Controlled Trial

OBJECTIVES

To evaluate the impact of metformin on in vitro fertilization (IVF) outcomes in overweight and obese women with polycystic ovary syndrome (PCOS).

METHODS

This was a randomized double-blind placebo-controlled study ( ClinicalTrials.gov : NCT02910817) carried out in a University IVF Center. The study included 102 overweight and obese women (body mass index [BMI] >24 kg/m²) with PCOS who underwent their first fresh autologous IVF-embryo transfer cycle and agreed to participate in the study. The study participants were randomized into 2 groups: metformin group received metformin (1000 mg per day) at the start of controlled ovarian stimulation (COH) until the day of the pregnancy check, and placebo group received placebo tablets in the same duration. The primary outcome measure was the total number of retrieved oocytes.

RESULTS

Both groups were homogenous in baseline demographic characteristics. Metformin group versus the placebo group demonstrated decrease in the mean number of the retrieved oocytes (9.06 ± 4.23 vs 16.86 ± 8.3, P < .01) and similar live birth rate (LBR; 25.5% vs 17.6%, P = .34). The number of fertilized oocytes was lower in the metformin group (5.65 ± 2.66 vs 9 ± 4.55, P < .01). However, the fertilization rate was similar in both groups (62.3% vs 53.4%, P = .10). There was no difference in the implantation rate (15.7% vs 11.8%, P = .32), multiple pregnancy rate (13.4% vs 3.9%, P = .08), or miscarriage rate (23.5% vs 35.7%, P = .46). No cases of ovarian hyperstimulation syndrome (OHSS) were observed in both groups.

CONCLUSION

Short-term administration of metformin to overweight or obese women with PCOS undergoing IVF decreased number of the retrieved oocytes but did not improve the LBR.

SYNOPSIS

Metformin use could decrease the number of retrieved oocytes in overweight and obese women with polycystic ovary syndrome undergoing IVF.

Insulin-sensitising drugs (metformin, rosiglitazone, pioglitazone, D-chiro-inositol) for women with polycystic ovary syndrome, oligo amenorrhoea and subfertility

BACKGROUND

Polycystic ovary syndrome (PCOS) is characterised by infrequent or absent ovulation, and high levels of androgens and insulin (hyperinsulinaemia). Hyperinsulinaemia occurs secondary to insulin resistance and is associated with increased risk of cardiovascular disease and diabetes mellitus. Insulin-sensitising agents such as metformin may be effective in treating PCOS-related anovulation.

OBJECTIVES

To evaluate the effectiveness and safety of insulin-sensitising drugs in improving reproductive and metabolic outcomes for women with PCOS undergoing ovulation induction.

SEARCH METHODS

We searched the following databases from inception to January 2017: Cochrane Gynaecology and Fertility Group Specialised Register, CENTRAL, MEDLINE, Embase, PsycINFO and CINAHL. We searched registers of ongoing trials and reference lists from relevant studies.

SELECTION CRITERIA

We included randomised controlled trials of insulin-sensitising drugs compared with placebo, no treatment, or an ovulation-induction agent for women with oligo and anovulatory PCOS.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed studies for eligibility and bias. Primary outcomes were live birth rate and gastrointestinal adverse effects. Secondary outcomes included other pregnancy outcomes, menstrual frequency and metabolic effects. We combined data to calculate pooled odds ratios (ORs) and 95% confidence intervals (CIs). We assessed statistical heterogeneity using the I2 statistic and reported quality of the evidence for primary outcomes using GRADE methodology.

MAIN RESULTS

We assessed the interventions metformin, clomiphene citrate, metformin plus clomiphene citrate, D-chiro-inositol, rosiglitazone and pioglitazone. We compared these with each other, placebo or no treatment. We included 48 studies (4451 women), 42 of which investigated metformin (4024 women). Evidence quality ranged from very low to moderate. Limitations were risk of bias (poor reporting of methodology and incomplete outcome data), imprecision and inconsistency. Metformin versus placebo or no treatmentThe evidence suggests that metformin may improve live birth rates compared with placebo (OR 1.59, 95% CI 1.00 to 2.51, 4 studies, 435 women, I2 = 0%, low-quality evidence). The metformin group experienced more gastrointestinal side effects (OR 4.76, 95% CI 3.06 to 7.41, 7 studies, 670 women, I2 = 61%, moderate-quality evidence) but had higher rates of clinical pregnancy (OR 1.93, 95% CI 1.42 to 2.64, 9 studies, 1027 women, I2 = 43%, moderate-quality evidence), ovulation (OR 2.55, 95% CI 1.81 to 3.59, 14 studies, 701 women, I2 = 58%, moderate-quality evidence) and menstrual frequency (OR 1.72, 95% CI 1.14 to 2.61, 7 studies, 427 women, I2 = 54%, low-quality evidence). There was no clear evidence of a difference in miscarriage rates (OR 1.08, 95% CI 0.50 to 2.35, 4 studies, 748 women, I2 = 0%, low-quality evidence). Metformin plus clomiphene citrate versus clomiphene citrate alone There was no conclusive evidence of a difference between the groups in live birth rates (OR 1.21, 95% CI 0.92 to 1.59, 9 studies, 1079 women, I2 = 20%, low-quality evidence), but gastrointestinal side effects were more common with combined therapy (OR 3.97, 95% CI 2.59 to 6.08, 3 studies, 591 women, I2 = 47%, moderate-quality evidence). However, the combined therapy group had higher rates of clinical pregnancy (OR 1.59, 95% CI 1.27 to 1.99, 16 studies, 1529 women, I2 = 33%, moderate-quality evidence) and ovulation (OR 1.57, 95% CI 1.28 to 1.92, 21 studies, 1624 women, I2 = 64%, moderate-quality evidence). There was a statistically significant difference in miscarriage rate per woman, with higher rates in the combined therapy group (OR 1.59, 95% CI 1.03 to 2.46, 9 studies, 1096 women, I2 = 0%, low-quality evidence) but this is of uncertain clinical significance due to low-quality evidence, and no clear difference between groups when we analysed miscarriage per pregnancy (OR 1.30, 95% CI 0.80 to 2.12, 8 studies; 400 pregnancies, I2 = 0%, low-quality evidence). Metformin versus clomiphene citrateWhen all studies were combined, findings for live birth were inconclusive and inconsistent (OR 0.71, 95% CI 0.49 to 1.01, 5 studies, 741 women, I2 = 86%, very low-quality evidence). In subgroup analysis by obesity status, obese women had a lower birth rate in the metformin group (OR 0.30, 95% CI 0.17 to 0.52, 2 studies, 500 women, I2 = 0%, very low-quality evidence), while data from the non-obese group showed a possible benefit from metformin, with high heterogeneity (OR 1.71, 95% CI 1.00 to 2.94, 3 studies, 241 women, I2 = 78%, very low-quality evidence). Similarly, among obese women taking metformin there were lower rates of clinical pregnancy (OR 0.34, 95% CI 0.21 to 0.55, 2 studies, 500 women, I2 = 0%, very low-quality evidence) and ovulation (OR 0.29, 95% CI 0.20 to 0.43 2 studies, 500 women, I2 = 0%, low-quality evidence) while among non-obese women, the metformin group had more pregnancies (OR 1.56, 95% CI 1.05 to 2.33, 5 studies, 490 women, I2 = 41%, very low-quality evidence) and no clear difference in ovulation rates (OR 0.81, 95% CI 0.51 to 1.28, 4 studies, 312 women, low-quality evidence, I2=0%). There was no clear evidence of a difference in miscarriage rates (overall: OR 0.92, 95% CI 0.50 to 1.67, 5 studies, 741 women, I2 = 52%, very low-quality evidence). D-chiro-inositol (2 studies), rosiglitazone (1 study) or pioglitazone (1 study) versus placebo or no treatmentWe were unable to draw conclusions regarding other insulin-sensitising drugs as no studies reported primary outcomes.

AUTHORS' CONCLUSIONS

Our updated review suggests that metformin alone may be beneficial over placebo for live birth, although the evidence quality was low. When metformin was compared with clomiphene citrate, data for live birth were inconclusive, and our findings were limited by lack of evidence. Results differed by body mass index (BMI), emphasising the importance of stratifying results by BMI. An improvement in clinical pregnancy and ovulation suggests that clomiphene citrate remains preferable to metformin for ovulation induction in obese women with PCOS.An improved clinical pregnancy and ovulation rate with metformin and clomiphene citrate versus clomiphene citrate alone suggests that combined therapy may be useful although we do not know whether this translates into increased live births. Women taking metformin alone or with combined therapy should be advised that there is no evidence of increased miscarriages, but gastrointestinal side effects are more likely.

The effect of metformin use on pregnancy rates among polycystic ovary syndrome patients undergoing in vitro fertilization: A retrospective-cohort study

Background

Metformin is widely used with gonadotropins by women with polycystic ovary syndrome (PCOS) during in vitro fertilization (IVF) to increase their chances of pregnancy. The aim of this study was to evaluate the efficacy of metformin in improving the rates of clinical pregnancy among women with PCOS undergoing IVF.

Methods

This was a retrospective cohort study of women with PCOS, aged 18–40 years, undergoing IVF during 2006–2012 at a University Hospital in Riyadh, Saudi Arabia. Baseline patient data including menstrual frequency, biochemical parameters such as fasting serum insulin (FSI) concentration, comorbidities, and the rates of ovulation and pregnancy were collected. Pregnancy rates were compared between the metformin and non-metformin groups.

Results

A total of 210 women with PCOS met the inclusion criteria and were included in the study. Of the 210 women with PCOS, 109 of them received metformin in addition to gonadotropins. Patients who received metformin were 16% less likely to be pregnant in comparison with those who did not receive metformin (OR = 0.840; 95% CI = 0.710–0.993; P = 0.0415), when controlled for baseline prolactin level, testosterone level, lipid panel, FSI concentration, fasting plasma glucose (FPG) concentration, comorbidities, duration of infertility, daily metformin dosage, and the previous use of clomiphene and/or leuprolide.

Conclusions

Metformin co-treatment during IVF may negatively affect pregnancy rates. Further well-designed, randomized, double-blind placebo-control clinical trials are needed to confirm the findings of this study.

Combining treatment with myo-inositol and D-chiro-inositol (40:1) is effective in restoring ovary function and metabolic balance in PCOS patients

Polycystic ovary syndrome (PCOS), a relevant cause of infertility, is a heterogeneous, endocrine disorder affecting up to 10-15% of women in reproductive age. Besides hyperandrogenism, insulin resistance (IR) plays a key role in such syndrome. Insulin-sensitizing drugs, such as Metformin, are effective in treating hyper-insulinemic PCOS patients. Recently, inositols - myo-inositol (MI) and D-chiro-inositol (DCI) - have shown to be an efficient and safe alternative in PCOS management, as both inositol isoforms are able to counteract downstream consequences of insulin resistance. Yet, whereas DCI contributes in mediating insulin activity mainly on non-ovarian tissues, MI displays specific effects on ovary, chiefly by modulating glucose metabolism and FSH-signaling. Moreover, MI may also improve ovarian functions by modulating steroid metabolism through non-insulin-dependent pathways. As DCI and MI activity likely involves different biological mechanisms, both inositol isoforms can be synergistically integrated according to a multitargeted design, by combining MI and DCI in a ratio corresponding to their physiological plasma relative amount (40:1). New experimental and clinical evidence with MI plus DCI evidenced the suitability of such integrated approach, and provided promising results. Further studies need to investigate thoroughly the molecular mechanism and confirm such preliminary data.

Strategies for improving outcome of assisted reproduction in women with polycystic ovary syndrome: systematic review and meta-analysis

OBJECTIVES

To identify, appraise and summarize the current evidence regarding the efficacy of strategies aimed at improving assisted reproductive techniques in women with polycystic ovary syndrome (PCOS).

METHODS

A comprehensive literature search of the standard medical databases was performed. The last electronic search was run in July 2015. The primary outcome measures were live birth/ongoing pregnancy and ovarian hyperstimulation syndrome (OHSS). The secondary outcome measures were clinical pregnancy and miscarriage.

RESULTS

We screened 1021 records and completely assessed 173, finally including 66 studies in the quantitative analysis. Many different interventions were assessed, however the overall quality of the studies was low. We observed moderate-quality evidence that there is no clinically relevant difference in live birth/ongoing pregnancy rates (relative risk (RR), 0.95 (95% CI, 0.84-1.08)), or clinical pregnancy (RR, 1.02 (95% CI, 0.91-1.15)) when comparing antagonist and agonist protocols for ovarian stimulation. Additionally, we found low-quality evidence that metformin improves live birth/ongoing pregnancy (RR, 1.28 (95% CI, 1.01-1.63)) and clinical pregnancy rates (RR, 1.26 (95% CI, 1.04-1.53)) when compared with placebo or no intervention. We further found low-quality evidence that there is no clinically relevant difference in live birth/ongoing pregnancy rates (RR, 1.03 (95% CI, 0.80-1.34)) and clinical pregnancy rates (RR, 0.99 (95% CI, 0.81-1.22)) when comparing human menopausal gonadotropin for inducing ovulation and artificial preparation with estradiol valerate for endometrial preparation for frozen embryo transfer (FET). Low-quality evidence suggests that mannitol compared with no intervention (RR, 0.54 (95% CI, 0.39-0.77)) and antagonist protocols compared with agonist protocols (RR, 0.63 (95% CI, 0.49-0.80)) reduce rates of OHSS.

CONCLUSION

There is low- to moderate-quality evidence suggesting that antagonist protocols are preferable to agonist ones, because they reduce the incidence of OHSS without interfering with clinical pregnancy and live birth for women with PCOS. Additionally there is low-quality evidence pointing to a benefit of metformin supplementation on clinical pregnancy and live birth; and that ovulation induction and administration of estradiol seem to be equally effective for endometrial preparation before FET for women with PCOS. For all other interventions, the evidence is of very low quality, not allowing any meaningful conclusions to be drawn. Estrategias para mejorar el resultado de la reproducción asistida en mujeres con síndrome de ovario poliquístico: revisión sistemática y metaanálisis RESUMEN OBJETIVOS: Identificar, evaluar y resumir la evidencia actual sobre la eficacia de las estrategias para mejorar las técnicas de reproducción asistida en mujeres con síndrome de ovario poliquístico (SOP). MÉTODOS: Se realizó una búsqueda exhaustiva de literatura en las bases de datos médicas estándar. La última búsqueda electrónica se realizó en julio de 2015. Las medidas de resultado primarias fueron los nacimientos vivos/embarazos en curso y el síndrome de hiperestimulación ovárica (SHO). Las medidas de resultado secundarias fueron el embarazo confirmado ecográficamente y el aborto.

RESULTADOS

Se cribaron 1021 registros, de los que se evaluaron por completo 173, para finalmente incluir 66 estudios en el análisis cuantitativo. Aunque se evaluaron muchas intervenciones diferentes, en general la calidad de los estudios fue baja. Se observó evidencia de calidad moderada de que no hay diferencias relevantes clínicamente en las tasas de nacimientos vivos/embarazos en curso (riesgo relativo (RR): 0,95 (IC 95%, 0,84-1,08)), o de embarazos confirmados ecográficamente (RR: 1,02 (IC 95%, 0,91-1,15)), cuando se comparan los protocolos de antagonistas y agonistas para la estimulación ovárica. Además, se encontró evidencia de baja calidad en que la metformina mejora las tasas de nacimientos vivos/embarazos en curso (RR: 1,28 (IC 95%, 1,01-1,63)) y de embarazos confirmados ecográficamente (RR: 1,26 (IC 95%, 1,04-1,53)) en comparación con un placebo o la no intervención. Se encontró también evidencia de baja calidad en que no hay diferencias relevantes clínicamente en las tasas de nacimientos vivos/embarazos en curso (RR: 1,03 (IC 95%, 0,80-1,34)) y las tasas de embarazos confirmados ecográficamente (RR: 0,99 (IC 95%, 0.81-1,22)) al comparar la gonadotropina menopáusica humana para la inducción de la ovulación y la preparación artificial con el valerato de estradiol para preparar el endometrio para la transferencia de embriones congelados (TEC). La baja calidad de la evidencia sugiere que el manitol, en comparación con la no intervención (RR: 0,54 (IC 95%, 0,39-0,77)), y los protocolos de antagonistas, en comparación con los protocolos de agonistas (RR: 0,63 (IC 95%, 0,49-0,80)), reducen las tasas de SHO. CONCLUSIÓN: Hay evidencia de calidad baja a moderada que sugiere que los protocolos de antagonistas son preferibles a los de agonistas, ya que reducen la tasa de SHO sin interferir con el embarazo confirmado ecográficamente y los nacimientos vivos en las mujeres con SOP. Además, existe evidencia de baja calidad que indica un beneficio del uso de metformina como aporte suplementario en embarazos confirmados ecográficamente y en nacimientos vivos; y que la inducción de la ovulación y la administración de estradiol parecen ser igualmente eficaces para la preparación del endometrio antes de la TEC en mujeres con SOP. Para el resto de procedimientos, la evidencia es de muy baja calidad, y por ello no permite extraer conclusiones importantes.

Inositol and human reproduction. From cellular metabolism to clinical use

Inositol is an organic compound of high biological importance that is widely distributed in nature. It belongs to the sugar family and is mainly represented by its two dominant stereoisomers: myo-inositol and D-chiro-inositol that are found in the organism in the physiological serum ratio 40:1. Inositol and its derivatives are important components of the structural phospholipids of the cell membranes and are precursors of the second messengers of many metabolic pathways. A high concentration of myoinositol is found in the follicular fluid and in semen. Inositol deficiency and the impairment of the inositol-dependent pathways may play an important role in the pathogenesis of insulin resistance and hypothyroidism. The results of the research also point out the potential beneficial role of inositol supplementation in polycystic ovarian syndrome and in the context of assisted reproduction technologies and in vitro fertilization. The main aim of the article is to overview the major inositol-dependent metabolic pathways and to discuss its importance for reproduction.

Pharmacologic Interventions in Preventing Ovarian Hyperstimulation Syndrome: A Systematic Review and Network Meta-Analysis

Ovarian hyperstimulation syndrome (OHSS) is a severe iatrogenic complication of controlled ovarian stimulation. Randomised controlled trials (RCTs) have proven several pharmacologic interventions to be effective in OHSS prevention, but these trials have seldom compared multiple drugs. We identified randomised controlled trials (RCTs) through June 2015 by searching databases and compared 11 intervention strategies in preventing OHSS (primary outcome) and their influence on pregnancy rate (secondary outcome). A network meta-analysis was used to evaluate the relative effectiveness among treatments and to create a rank probability table. Thirty-one RCTs were identified, including 7181 participants. Five pharmacologic interventions were superior to placebo in decreasing OHSS incidence: aspirin [relative risk (RR) 0.07, 95% credible interval (CrI) 0.01-0.30, p < 0.05], intravenous (IV) calcium [RR 0.11, 95% CrI 0.02-0.54, p < 0.05], cabergoline [RR 0.17, 95% CrI 0.06-0.43, p < 0.05], metformin [RR 0.20, 95% CrI 0.07-0.59, p < 0.05] and IV hydroxyethyl starch (HES) [RR 0.26, 95% CrI 0.05-0.99, p < 0.05]. The rank probability demonstrated aspirin (Rank 1: 36%) and IV calcium (Rank 1: 35%) to be the most efficacious. Additionally, albumin might decrease the pregnancy rate when compared with placebo [RR 0.85, 95% CI 0.74-0.97, p < 0.05]. This conclusion provides a relative standard and objective reference for choosing an OHSS prophylactic agent.

Polycystic ovary syndrome: chemical pharmacotherapy

INTRODUCTION

Polycystic ovary syndrome (PCOS) is the most common reproductive endocrine disease among women of childbearing age. The clinical features are heterogeneous and vary in intensity. Hirsutism, menstrual disorders and infertility are the most frequent conditions observed; however, long-term complications (dyslipidemia, hypertension, cardiovascular disease, type 2 diabetes mellitus, endometrial cancer) are also often described. Each disorder may be managed by tailored strategies, employing sequential or combined pharmacological and/or non-pharmacological treatment.

AREAS COVERED

The authors review the drugs used for PCOS management and discuss new approaches. A systematic MEDLINE search regarding the randomized controlled trials, retrospective and observational studies about medical treatments of PCOS, the Cochrane library for reviews and also search for registered trials on ClinicalTrials.gov is performed.

EXPERT OPINION

A uniform treatment for PCOS patients does not exist. Clinicians should perform an accurate evaluation of patients' characteristics, identifying the phenotypic target and, subsequently, the best-tailored treatment to manage one or more clinical issues. Lifestyle intervention should always be the first recommended approach unless other issues indicate that drug or hormonal interventions are superior.

A systematic review and meta-analysis of metformin among patients with polycystic ovary syndrome undergoing assisted reproductive technology procedures

BACKGROUND

Metformin is used among patients with polycystic ovary syndrome (PCOS), but findings for its effects on outcomes of assisted reproductive technology (ART) have been conflicting.

OBJECTIVES

To compare ART outcomes among women with PCOS who were and were not given metformin.

SEARCH STRATEGY

Databases were searched for reports published in English between 2002 and 2013, using combinations of the terms "polycystic ovary syndrome," "PCOS," "insulin-sensitizing," and "metformin."

SELECTION CRITERIA

Randomized controlled trials of metformin versus placebo among women with PCOS undergoing ART were included if they assessed rates of pregnancy, live birth, spontaneous abortion, multiple pregnancy, and/or ovarian hyperstimulation syndrome (OHSS).

DATA COLLECTION AND ANALYSIS

Data were extracted from included studies. The Mantel-Haenzel random-effects model was used for meta-analyses.

MAIN RESULTS

Twelve studies (1516 participants) were included. No significant differences were recorded between metformin and placebo groups for rates of pregnancy (risk ratio [RR] 1.11, 95% CI 0.92-1.33), live birth (RR 1.12, 0.92-1.36), spontaneous abortion (RR 1.00, 0.60-1.67), or multiple pregnancy (RR 0.96, 0.47-1.96). However, OHSS rate was significantly lower among patients who received metformin than among those who received placebo (RR 0.44, 0.26-0.77).

CONCLUSIONS

Metformin does not improve ART outcomes among patients with PCOS, but does significantly reduce their risk of OHSS.

Reflections on inositol(s) for PCOS therapy: steps toward success

In polycystic ovary syndrome (PCOS) pathogenesis, both the insulin resistance and the related compensatory hyperinsulinemia are involved. Despite their similarities, Myo-inositol (MI) and d-chiro-inositol (DCI) play different roles in PCOS etiology and therapy. Indeed, in tissue such as the liver both molecules are involved in the insulin signaling, i.e. MI promotes glucose uptake and DCI glycogen synthesis. In reproductive tissue such as the ovary, MI regulates glucose uptake and follicle stimulating hormone (FSH) signaling, whereas DCI is devoted to the insulin-mediated androgen production. The new hypothesis on "DCI paradox" in the ovary has provided the key for a better understanding. Unlike other tissues, ovary is not insulin resistant, indeed because the epimerase enzyme, which converts MI to DCI, is insulin dependent, the "DCI paradox" hypothesis suggests that in the ovary of PCOS women, an increased epimerase activity leads to a DCI overproduction and MI depletion. This imbalance could be the cause of the poor oocyte quality and the impairment in the FSH signaling. Owing to this situation, the focal point is the administration of both MI and DCI in a proper ratio for treating PCOS. This topic, with several other "hot" issues, was the driving thread in the discussion between the two scientists.

Ovarian hyperstimulation syndrome: pathophysiology, staging, prediction and prevention

OBJECTIVE

To identify, appraise and summarize the current evidence regarding the pathophysiology, staging, prediction and prevention of ovarian hyperstimulation syndrome (OHSS).

METHODS

Two comprehensive systematic reviews were carried out: one examined methods of predicting either high ovarian response or OHSS and the other examined interventions aimed at reducing the occurrence of OHSS. Additionally, we describe the related pathophysiology and staging criteria.

RESULTS

Seven studies examining methods of predicting OHSS and eight more examining methods of predicting high ovarian response to controlled ovarian stimulation were included. Current evidence shows that the best methods of predicting high response are antral follicle count and anti-Müllerian hormone levels, and that a high ovarian response (examined by the number of large follicles, estradiol concentration or the number of retrieved oocytes) is the best method of predicting the occurrence of OHSS. Ninety-seven randomized controlled trials examining the effect of several interventions for reducing the occurrence of OHSS were included. There was high-quality evidence that replacing human chorionic gonadotropin by gonadotropin-releasing hormone agonists or recombinant luteinizing hormone, and moderate-quality evidence that antagonist protocols, dopamine agonists and mild stimulation, reduce the occurrence of OHSS. The evidence for the effect of the other interventions was of low/very low quality. Additionally, we identified and described 12 different staging criteria.

CONCLUSIONS

There are useful predictive tools and several preventive interventions aimed at reducing the occurrence of OHSS. Acknowledging and understanding them are of crucial importance for planning the treatment of, and, ultimately, eliminating, OHSS while maintaining high pregnancy rates.

Metformin use in patients undergoing in vitro fertilization treatment: results of a worldwide web-based survey

PURPOSE

To identify trends regarding therapeutic approaches to metformin administration in patients undergoing in vitro fertilization (IVF) treatment worldwide.

METHODS

A retrospective evaluation utilizing the results of a web-based survey, IVFWorldwide ( www.IVF-worldwide.com/ ), was performed.

RESULTS

Responses from 101 centers performing a total of 50,800 annual IVF cycles was performed. Of these cycles, 10.4% (n = 5,260) reported metformin use during IVF cycles. Indications for metformin use in IVF cycles included polycystic ovary syndrome (PCOS) patients who were habitual abortions (67%), had prior poor egg quality (61%), had high serum insulin levels (56%). Less reported was PCOS with obesity/anvoulation (29%), PCOS with multiple manifestations (23%) and glucose intolerance and insulin resistance (23%). Over half of cycles (54%) treated patients with metformin up to 3 months prior to starting IVF. A majority (82%) of IVF cycles utilized 1500-2000 mg/day of metformin. A nearly equal percentage of centers continued metformin up to a positive β-HCG test (35%) or to 12 weeks gestation (33%). 70% of IVF cycles reported increased pregnancy rates and decreased miscarriage rates due to the use of metformin. 75% reported the data in the literature is not sufficient for reaching a definitive conclusion concerning metformin treatment in patients undergoing IVF.

CONCLUSIONS

While metformin is used worldwide as an adjunct to standard IVF protocols, there is much variation in its use and the majority of centers report lack of evidence supporting its use.

Metformin treatment before and during IVF or ICSI in women with polycystic ovary syndrome

BACKGROUND

The use of insulin-sensitising agents, such as metformin, in women with polycystic ovary syndrome (PCOS) who are undergoing ovulation induction or in vitro fertilisation (IVF) cycles has been widely studied. Metformin reduces hyperinsulinaemia and suppresses the excessive ovarian production of androgens. As a consequence, it is suggested that metformin could improve assisted reproductive techniques (ART) outcomes, such as ovarian hyperstimulation syndrome (OHSS), pregnancy and live birth rates.

OBJECTIVES

To determine the effectiveness and safety of metformin as a co-treatment during IVF or intracytoplasmic sperm injection (ICSI) in achieving pregnancy or live birth in women with PCOS.

SEARCH METHODS

We searched the Cochrane Menstrual Disorders and Subfertility Group Trials Register, Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library), MEDLINE, EMBASE, LILACS, the metaRegister of Controlled Trials and reference lists of articles (up to 15 October 2014).

SELECTION CRITERIA

Types of studies: randomised controlled trials (RCTs) comparing metformin treatment with placebo or no treatment in women with PCOS who underwent IVF or ICSI treatment.

TYPES OF PARTICIPANTS

women of reproductive age with anovulation due to PCOS with or without co-existing infertility factors.Types of interventions: metformin administered before and during IVF or ICSI treatment.Types of outcome measures: live birth rate, clinical pregnancy rate, miscarriage rate, incidence of ovarian hyperstimulation syndrome , incidence of participant-reported side effects, serum oestradiol level on the day of trigger, serum androgen level, and fasting insulin and glucose levels.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected the studies, extracted the data according to the protocol and assessed study quality. The overall quality of the evidence was assessed using GRADE methods.

MAIN RESULTS

We included nine randomised controlled trials involving a total of 816 women with PCOS. When metformin was compared with placebo there was no clear evidence of a difference between the groups in live birth rates (OR 1.39, 95% CI 0.81 to 2.40, five RCTs, 551 women, I(2) = 52%, low-quality evidence). Our findings suggest that for a woman with a 32 % chance of achieving a live birth using placebo or other treatment, the corresponding chance using metformin treatment would be between 28% and 53%.When metformin was compared with placebo or no treatment, clinical pregnancy rates were higher in the metformin group (OR 1.52; 95% CI 1.07 to 2.15; eight RCTs, 775 women, I(2) = 18%, moderate-quality evidence). This suggests that for a woman with a 31% chance of achieving a clinical pregnancy using placebo or no treatment, the corresponding chance using metformin treatment would be between 32% and 49%.The risk of ovarian hyperstimulation syndrome was lower in the metformin group (OR 0.29; 95% CI 0.18 to 0.49, eight RCTs, 798 women, I(2) = 11%, moderate-quality evidence). This suggests that for a woman with a 27% risk of having OHSS without metformin the corresponding chance using metformin treatment would be between 6% and 15%.Side effects (mostly gastrointestinal) were more common in the metformin group (OR 4.49, 95% CI 1.88 to 10.72, for RCTs, 431 women, I(2)=57%, low quality evidence)The overall quality of the evidence was moderate for the outcomes of clinical pregnancy, OHSS and miscarriage, and low for other outcomes. The main limitations in the evidence were imprecision and inconsistency.

AUTHORS' CONCLUSIONS

This review found no conclusive evidence that metformin treatment before or during ART cycles improved live birth rates in women with PCOS. However, the use of this insulin-sensitising agent increased clinical pregnancy rates and decreased the risk of OHSS.

The rationale of the myo-inositol and D-chiro-inositol combined treatment for polycystic ovary syndrome

PCOS is one of the most common endocrine disorders affecting women and it is characterized by a combination of hyper-androgenism, chronic anovulation, and insulin resistance. While a significant progress has recently been made in the diagnosis for PCOS, the optimal infertility treatment remains to be determined. Two inositol isomers, myo-inositol (MI) and D-chiro-inositol (DCI) have been proven to be effective in PCOS treatment, by improving insulin resistance, serum androgen levels and many features of the metabolic syndrome. However, DCI alone, mostly when it is administered at high dosage, negatively affects oocyte quality, whereas the association MI/DCI, in a combination reproducing the plasma physiological ratio (40:1), represents a promising alternative in achieving better clinical results, by counteracting PCOS at both systemic and ovary level.

First-trimester exposure to metformin and risk of birth defects: a systematic review and meta-analysis

BACKGROUND

Metformin is generally considered a non-teratogenic drug; however, only a few studies specifically designed to assess the rate of congenital anomalies after metformin use have been published in the literature. The objects of the present study were to review all of the prospective and retrospective studies reporting on women treated with metformin at least during the first trimester of their pregnancy and to estimate the overall rate of major birth defects.

METHODS

Databases were searched for English language articles until December 2013. Inclusion criteria for the meta-analysis were: a case group of women with PCOS or pre-pregnancy type 2 diabetes and first-trimester exposure to metformin; a disease-matched control group which was not exposed to metformin or other oral anti-diabetic agents; and a list of the major anomalies in both the study and the control groups. A random effects model was used for the meta-analysis of data, using odds ratios. Studies not fulfilling the inclusion criteria for the meta-analysis but reporting relevant data on major malformations in women diagnosed with PCOS were then used to estimate the overall birth defects rate.

RESULTS

Meta-analysis of nine controlled studies with women affected by PCOS detected that the rate of major birth defects in the metformin-exposed group was not statistically increased compared with the disease-matched control group and that there was no significant heterogeneity among the studies. The metformin-exposed sample was composed of 351 pregnancies and the OR of major birth defects was 0.86 (95% confidence interval: 0.18-4.08; Pheterogeneity = 0.71). By evaluating all of the non-overlapping PCOS studies reported in the literature, even those without an appropriate control group, the overall rate of major anomalies was 0.6% in the sample of 517 women who discontinued the therapy upon conception or confirmation of pregnancy and 0.5% in the sample of 634 women who were treated with metformin throughout the first trimester of their pregnancy. Regarding type 2 diabetic women, we did not identify a sufficient number of studies with metformin exposure during the first trimester to proceed with the meta-analysis.

CONCLUSIONS

There is currently no evidence that metformin is associated with an increased risk of major birth defects in women affected by PCOS and treated during the first trimester. However larger ad hoc studies are warranted in order to definitely confirm the safety and efficacy of this drug in pregnancy.

Metformin inhibits follicle-stimulating hormone (FSH) action in human granulosa cells: relevance to polycystic ovary syndrome

BACKGROUND

Women with anovulatory polycystic ovary syndrome (PCOS) are generally insulin-resistant and as a consequence are often treated with the biguanide metformin. Results with metformin have, however, been variable with some studies demonstrating induction of regular cycles and an increase in ovulation, whereas others do not. Hence more understanding is needed regarding the mechanism of metformin's actions in ovarian granulosa cells especially in light of previous demonstrations of direct actions.

OBJECTIVE

The aim of this study was to investigate metformin's interaction with the FSH/cAMP/protein kinase A pathway, which is the primary signaling pathway controlling CYP19A1 (aromatase) expression in the ovary.

METHODS

The effect of metformin on FSH and forskolin-stimulated aromatase expression in human granulosa cells was measured by quantitative real-time PCR. Activity was assessed after transfection with a promoter II-luciferase construct, and by an RIA measuring conversion of androgen to estrogens. The effect on FSH receptor (FSHR) mRNA was assessed by quantitative PCR. Levels of phosphorylated cAMP response element binding protein (CREB) and CREB-regulated transcription coactivator 2 (CRTC2) were measured by Western blotting and cAMP by a bioluminescent assay.

RESULTS

Metformin markedly reduced FSH but not forskolin-stimulated aromatase expression and activity. This effect was exerted by inhibition of basal and ligand-induced up-regulation of FSHR expression. Metformin also reduced FSH-induced phosphorylation of CREB and hence CRE activity, which could potentially disrupt the CREB-CREB-binding protein-CRTC2 coactivator complex that binds to CRE in promoter II of the aromatase gene. This is mediated in an AMP-activated protein kinase-independent manner, and does not involve alteration of cAMP levels.

CONCLUSION

These finding have implications for the use of metformin in the treatment of anovulation in women with PCOS.

CONCERN: Does ovary need D-chiro-inositol?

BACKGROUND

Polycystic Ovary Syndrome (PCOS) is a multifactorial pathology that affects 10% of the women in reproductive age being the main cause of infertility due to menstrual dysfunction. Since 1980, it is known that PCOS is associated with insulin resistance (IR). The recognition of this association has prompted extensive investigation on the relationship between insulin and gonadal function, and has turned insulin sensitizer agent as the main therapeutic choice. In particular two different polyalcohol myo-inositol and D-chiro-inositol have been shown to improve insulin resistance, hyperandrogenism and to induce ovulation in PCOS women. In particular, while data on myo-inositol and restored ovulation were consistent, data on D-chiro-inositol were not . Recently, a comparative study, proposed a D-chiro-inositol paradox in the ovary of PCOS patients hypothesizing that only myo-inositol has a specific ovarian action. In the present study we aim to further study the role played by D-chiro-inositol at ovarian level.

METHODS

A total of 54 women, aged <40 years and diagnosed with PCOS were enrolled in this study. Patients with insulin resistance and/or hyperglycaemia were excluded from the study. Patients were randomly divided into 5 groups (n=10-12): a placebo group, and 4 groups (A-D) that received 300-600-1200-2400 mg of DCI daily respectively. All treatments were carried out for 8 weeks before follicle stimulating hormone (rFSH) administration.

RESULTS

Total r-FSH units increased significantly in the two groups that received the higher doses of DCI. The number of immature oocytes was significantly increased in the three groups that received the higher doses of DCI. Concurrently, the number of MII oocytes was significantly lower in the D group compared to placebo group. Noteworthy, the number of grade I embryos was significantly reduced by DCI supplementation.

CONCLUSIONS

Indeed, increasing DCI dosage progressively worsens oocyte quality and ovarian response.