Cheraghi 2016

Methods	Prospective randomised placebo‐controlled pilot trial
Participants	Infertile Iranian women with PCOS, aged from 25 ‐ 35 years, undergoing ICSI treatment (N = 80) Inclusion criteria: Women who met the Rotterdam criteria for PCOS Exclusion criteria: Hypersensitivity to either MET (metformin) or NAC, infertility factors other than anovulation, male infertility, pelvic organic pathologies, congenital adrenal hyperplasia, thyroid dysfunction, Cushing’s syndrome, hyperprolactinaemia, androgen‐secreting neoplasia, diabetes mellitus, consumption of medications affecting carbohydrate metabolism and hormonal analogues other than progesterone 2 months prior to enrolment in the study and severe hepatic or kidney disease
Interventions	4 groups (n = 20 in each, 5 dropouts from each) 1. Placebo oral rehydration salts; 3 times a day 2. Metformin 500 mg: 1 tablet 3 times a day 3. NAC 600 mg: 1 tablet 3 times a day 4. Metformin 500 mg: 1 tablet 3 times a day + NAC 600 mg: 1 tablet 3 times a day All treatments were administered for 6 weeks
Outcomes	Oocyte and embryo quality Endocrine parameters Clinical pregnancy Side effects
Notes	Iran, study ran from July 2012 to February 2013 Need to clarify primary and secondary outcomes Author emailed regarding RoB, live birth and miscarriage information; no reply Funded by institutional grant
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	State "random" but method not described
Allocation concealment (selection bias)	Unclear risk	Not stated
Blinding (performance bias and detection bias) All outcomes	High risk	Double‐blinded placebo‐controlled, but the placebo group received oral rehydration salts, which are usually in solution, while the treatments were tablets
Incomplete outcome data (attrition bias) All outcomes	High risk	Dropouts accounted for, but > 25% dropout
Selective reporting (reporting bias)	Low risk	Outcomes reported
Other bias	Low risk	No other bias found