Inositol treatment of anovulation in women with polycystic ovary syndrome: a meta-analysis of randomised trials

BACKGROUND: Polycystic ovary syndrome is a common cause of anovulation and infertility, and a risk factor for development of metabolic syndrome and endometrial cancer.

OBJECTIVES: Systematic review and meta-analysis of randomised controlled trials that evaluated the effects of inositol as an ovulation-induction agent.

SEARCH STRATEGY: We searched MEDLINE, EMBASE, Cochrane and ISI conference proceedings, Register and Meta-register for RCTs and WHO trials' search portal.

SELECTION CRITERIA: We included studies that compared inositol with placebo or other ovulation induction agents.

DATA COLLECTION AND ANALYSIS: Quality of studies was assessed for risk of bias. Results were pooled using random effects meta-analysis and findings were reported as relative risk or standardized mean differences.

MAIN RESULTS: We included 10 randomised trials. Total women on inositol were 362 (myo-inositol = 257; di-chiro-inositol = 105), placebo were 179 and metformin were 60. Inositol was associated with significantly improved ovulation rate (RR 2.3; 95% CI 1.1, 4.7; I2 = 75%) and increased frequency of menstrual cycles (RR 6.8; 95% CI 2.8, 16.6; I2 = 0%) compared with placebo. One study reported on clinical pregnancy rate with inositol compared with placebo (RR 3.3; 95% CI 0.4, 27.1), and one study compared with metformin (RR 1.5; 95% CI 0.7, 3.1). No studies evaluated live birth and miscarriage rates.

CONCLUSIONS: Inositol appears to regulate menstrual cycles, improve ovulation and induce metabolic changes in PCOS, however evidence is lacking for pregnancy, miscarriage or live birth. Further well-designed multicenter trial to address this issue to provide robust evidence of benefit is warranted. This article is protected by copyright. All rights reserved.