Schachter 2007

Methods	Randomised trial
Participants	Infertile women diagnosed with insulin‐resistant PCOS (n = 102) 18 women were scheduled for ovulation induction and 84 for IVF/ICSI Mean age: 28.8 ± 0.4 years
Interventions	1. Folic acid 0.4 mg a day (n = 23) 2. Metformin 1700 mg a day (2 divided doses of 850 mg tablets) + folic acid 0.4 mg: 1 tablet a day (n = 28) 3. Vitamin B complex (50 mg B6, 400 ug folic acid, 500 ug B12, 1 g trimethylglycine and 6 mg pyridoxal‐5‐phosphate): 1 tablet a day (n = 24) 4. Metformin 1700 mg a day (2 divided doses of 850 mg tablets) + vitamin B complex: 1 tablet a day (n = 27) Women were recruited over 14 months and outcomes were measured over 3 cycles All groups were given folic acid
Outcomes	Homocysteine levels Cumulative clinical pregnancy rate over 3 cycles Ongoing pregnancy rate
Notes	Israel Tel Aviv, study dates not reported Dr Morey Schachter ivfdoc@asaf.health.gov.il. Email sent 8th December 2015, no reply Laboratory costs were partially funded by a company producing vitamins and supplements
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	"These 102 patients were randomized before treatment, and after giving informed consent, assigned to one of four groups by opening sealed envelopes containing computer generated random assignation numbers"
Allocation concealment (selection bias)	Low risk	Sealed envelopes containing computer‐generated random assignation numbers"
Blinding (performance bias and detection bias) All outcomes	Unclear risk	Unknown
Incomplete outcome data (attrition bias) All outcomes	Low risk	No attrition
Selective reporting (reporting bias)	Low risk	No known selective reporting
Other bias	Low risk	No other bias found