Consensus on infertility treatment related to polycystic ovary syndrome

Evidence-based and potential benefits of metformin in the polycystic ovary syndrome: a comprehensive review

Metformin is an insulin sensitizer widely used for the treatment of patients affected by type 2 diabetes mellitus. Because many women with polycystic ovary syndrome (PCOS) are insulin resistant, metformin was introduced in clinical practice to treat these patients also. Moreover, metformin's effect has other targets beside its insulin-sensitizing action. The present review was aimed at describing all evidence-based and potential uses of metformin in PCOS patients. In particular, we will analyze the uses of metformin not only for the treatment of all PCOS-related disturbances such as menstrual disorders, anovulatory infertility, increased abortion, or complicated pregnancy risk, hyperandrogenism, endometrial, metabolic and cardiovascular abnormalities, but also for the prevention of the syndrome.

Is pharmacogenomics our future? Metformin, ovulation and polymorphism of the STK11 gene in polycystic ovary syndrome

Evaluation of: Legro RS, Barnhart HX, Schlaff WD et al.: Ovulatory response to treatment of polycystic ovary syndrome is associated with a polymorphism in the STK11 gene. J. Clin. Endocrinol. Metab. 93(3), 792-800 (2008). The current study by Legro et al. is a substudy of the recent multicenter, double-blinded, prospective study Pregnancy in Polycystic Ovary Syndrome. Legro et al. randomly assigned 626 infertile women with polycystic ovary syndrome to receive 50 mg clomiphene citrate plus placebo (n = 209), 2 g extended-release metformin plus placebo (n = 208), or a combination of metformin and clomiphene (n = 209) for up to six cycles. Of 626 patients in the original study, 312 women participated in the pharmacogenetic substudy; 98 received metformin XR (2 g/day), 102 clomiphene and 112 combined clomiphene-metformin XR treatment. This study was designed "to identify predictive genetic polymorphism and other determinants of ovulatory response" in prospective fashion. Candidate genes tested included estrogen receptor 1 (ESR1), CYP genes (CYP2C9 and CYP2D6) and STK11. STK11, formerly known as LKB1, is a serine-threonine kinase gene expressed in the liver, which phosphorylates and activates AMP-activated protein kinase. It was shown to be a site of metformin action. The C allele of a SNP in the STK11 gene was associated with a significantly decreased chance of ovulation in polycystic ovary syndrome women treated with metformin. In analysis of ovulation per cycle, the adjusted odds ratio for CC versus GG (wild-type normal) was 0.30 (95% CI: 0.14-0.66) and the odds ratio for CG versus GG was 0.30 (95% CI: 0.14-0.66). This elegant study is of great importance because despite treatment, many women with polycystic ovary syndrome fail to ovulate, 24.9% in the clomiphene group, 44.7% in the metformin group and 16.7% in the clomiphene-metformin group.

Comparison of letrozole with continuous gonadotropins and clomiphene-gonadotropin combination for ovulation induction in 1387 PCOS women after clomiphene citrate failure: a randomized prospective clinical trial

PURPOSE

Letrozole, though reported to be an effective ovulation inducing agent, warrants larger randomized trials. The purpose of this study is to compare the efficacy of letrozole with that of rFSH and clomiphene citrate(CC)/rFSH for ovarian stimulation in IUI cycles.

METHODS

Randomized, prospective, single-blinded clinical trial. 1387 PCOS women after CC failure were randomized into three groups: Group A received letrozole, Group B received CC with two doses rFSH and Group C received continuous rFSH day 2 onwards until hCG injection.

RESULTS

Group A, B and C had an ovulation rate of 79.30%, 56.95% and 89.89% and cycle cancellation rate of 20.70%, 43.05% and 10.11%, respectively. Pregnancy rates in Group A, B and C were 23.39%, 14.35% and 17.92%, while the miscarriage rates were 13.80%, 16.67% and 14.52%, respectively.

CONCLUSION

Letrozole appears to be a suitable ovulation inducing agent in PCOS women with CC failure and is found to be most effective when baseline estradiol level >60 pg/ml.

Obesity and polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is one of the most common endocrinopathies in women of fertile age. Obesity is encountered in 30-70% of PCOS-affected women, and its presence significantly modifies both clinical and laboratory expression of the syndrome. Obesity increases the risk of co-morbidities associated with PCOS, such as impaired glucose tolerance and type 2 diabetes mellitus, hyperlipidemia and arterial hypertension. The etiopathogenesis of obesity in PCOS has not yet been exactly clarified. There clearly is a vicious circle of abdominal obesity, insulin resistance, and hyperadrogenemia. Differences in ghrelin and neuropeptide Y levels between PCOS patients and those with simple obesity were also described. Weight loss is the first choice recommendation for the treatment of clinical manifestations of PCOS, such as menstrual cycle irregularities, infertility or hirsutism. However, the best treatment approach in obese PCOS patients remains to be defined. Studies concerning different weight loss regimens, antiobesity drugs, bariatric surgery, insulin sensitizers, and hormonal therapy are reviewed.

What is the preferred GnRH analogue for polycystic ovary syndrome patients undergoing controlled ovarian hyperstimulation for in vitro fertilization?

In an attempt to evaluate the influence of the GnRH analogue used during controlled ovarian hyperstimulation (COH) on the outcome of IVF cycles of polycystic ovary syndrome (PCOS) patients, we studied 152 IVF cycles. The PCOS patients undergoing COH using the GnRH agonist protocol (n = 50) showed a significantly higher pregnancy rate (36% vs. 19.6%, respectively), compared with the GnRH antagonist protocol (n = 102).

Metformin in the treatment of infertility in polycystic ovarian syndrome: an alternative perspective

This editorial discusses the recent European Society for Human Reproduction and Embryology/American Society for Reproductive Medicine recommendations on the treatment of infertility in polycystic ovarian syndrome. Evidence is provided for the use of metformin in selected patients.