Increase of multiple pregnancies caused by ovulation induction with gonadotropin in combination with metformin in infertile women with polycystic ovary syndrome

Use of exogenous gonadotropins for ovulation induction in anovulatory women: a committee opinion

This document reviews gonadotropin treatment for ovulation induction in anovulatory women and outlines the recommended pretreatment evaluation, indications, treatment regimens, and complications of gonadotropin treatment. It replaces the document with a similar name, last published in 2008 (Fertil Steril 2008;90:S7-12).

Metformin during ovulation induction with gonadotrophins followed by timed intercourse or intrauterine insemination for subfertility associated with polycystic ovary syndrome

BACKGROUND

Clomiphene citrate (CC) is generally considered first-line treatment in women with anovulation due to polycystic ovary syndrome (PCOS). Ovulation induction with follicle-stimulating hormone (FSH; gonadotrophins) is second-line treatment for women who do not ovulate or conceive while taking CC. Metformin may increase the effectiveness of ovulation induction with gonadotrophins and may promote safety by preventing multiple pregnancy.

OBJECTIVES

To determine the effectiveness and safety of metformin co-treatment during ovulation induction with gonadotrophins with respect to rates of live birth and multiple pregnancy in women with PCOS.

SEARCH METHODS

We searched the Cochrane Gynaecology and Fertility (CGF) Group specialised register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, PsycINFO and the Cumulative Index to Nursing and Allied Health Literature (CINAH) on 8 June 2016, and the reference lists of included and other relevant studies. We searched ongoing trials registries in the World Health Organization (WHO) portal and on clinicaltrials.gov on 4 September 2016.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) reporting data on comparison of clinical outcomes in women with PCOS undergoing ovulation induction with gonadotrophins plus metformin versus gonadotrophins alone or gonadotrophins plus placebo.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures recommended by Cochrane. Primary review outcomes were live birth rate and multiple pregnancy rate. Secondary outcomes were ovulation rate, clinical pregnancy rate, ovarian hyperstimulation syndrome (OHSS) rate, miscarriage rate, cycle cancellation rate and adverse effects.

MAIN RESULTS

We included five RCTs (with 264 women) comparing gonadotrophins plus metformin versus gonadotrophins. The gonadotrophin used was recombinant FSH in four studies and highly purified FSH in one study. Evidence was of low quality: The main limitations were serious risk of bias due to poor reporting of study methods and blinding of participants and outcome assessors. Live birth Metformin plus FSH was associated with a higher cumulative live birth rate when compared with FSH (odds ratio (OR) 2.31, 95% confidence interval (CI) 1.23 to 4.34; two RCTs, n = 180; I² = 0%; low-quality evidence). This suggests that if the chance of live birth after FSH is assumed to be 27%, then the chance after addition of metformin would be between 32% and 60%. Other pregnancy outcomes Metformin use was associated with a higher ongoing pregnancy rate (OR 2.46, 95% CI 1.36 to 4.46; four RCTs, n = 232; I² = 0%; low-quality evidence) and a higher clinical pregnancy rate (OR 2.51, 95% CI 1.46 to 4.31; five RCTs, n = 264; I² = 0%; low-quality evidence). Multiple pregnancy Results showed no evidence of a difference in multiple pregnancy rates between metformin plus FSH and FSH (OR 0.55, 95% CI 0.15 to 1.95; four RCTs, n = 232; I² = 0%; low-quality evidence) and no evidence of a difference in rates of miscarriage or OHSS. Other adverse effects Evidence was inadequate as the result of limited available data on adverse events after metformin compared with after no metformin (OR 1.78, 95% CI 0.39 to 8.09; two RCTs, n = 91; I² = 0%; very low-quality evidence).

AUTHORS' CONCLUSIONS

Preliminary evidence suggests that metformin may increase the live birth rate among women undergoing ovulation induction with gonadotrophins. At this moment, evidence is insufficient to show an effect of metformin on multiple pregnancy rates and adverse events. Additional trials are necessary before we can provide further conclusions that may affect clinical practice.

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 administration in patients with polycystic ovary syndrome who receive gonadotropins for in vitro fertilization cycles: 10-year experience in a large infertile population

The study aim was to evaluate our personal experience regarding the use and the reproductive effect of metformin administration in a large population of infertile patients with polycystic ovary syndrome (PCOS) undergoing gonadotropins ovarian stimulation for in vitro fertilization (IVF). Infertile patients with PCOS undergoing gonadotropins ovarian stimulation with (metformin group, n = 191) or without (control group, n = 187) metformin and IVF were evaluated. Treatment characteristics, patients' data and reproductive outcomes were evaluated. In all cases, metformin with an immediate-release formulation was administered, and in most of cases it was given as pre- and co-treatment (74.9%) and at a dosage of 1700 mg/day (59.7%). Stimulation length and gonadotropins doses were significantly (p < 0.05) higher in metformin group than in control group. The number of dominant follicles on day of ovarian maturation triggering and peak oestradiol levels were significantly (p < 0.05) lower in metformin group than in control group. Cycle cancellation rate under metformin resulted significantly influenced by interaction with body mass index (BMI), age and basal follicle-stimulating hormone (FSH) levels. Notwithstanding, metformin use in infertile PCOS patients who receive gonadotropins for IVF is not standardized, it seems to modulate the ovarian response to stimulation. This effect may benefit or harm on the basis of ovarian reserve and patients' characteristics.

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.