Valeri 2015

Methods	Double‐blind randomised controlled trial
Participants	Infertile women aged > 40 years undergoing IVF (n = 358)
Interventions	1. Melatonin 5 mg: 1 tablet a day (n = 178) 2. No treatment (n = 180) Trial ran from July 2009 to December 2013
Outcomes	Oocyte maturity Oxidative stress Antioxidative capacity Progesterone concentration in follicular fluid Embryo grade
Notes	Conducted in Italy, trial ran from July 2009 to Decenber 2013 Trial funded by pharmaceutical company Trial registration no: NCT01540747 Email sent to Dr Pacchiarotti regarding the methods of this trial. Dr Pacchiarotti replied 20th March 2017 giving some methods information
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Computer‐generated
Allocation concealment (selection bias)	Unclear risk	Unknown
Blinding (performance bias and detection bias) All outcomes	Unclear risk	Double‐blind but control is no treatment
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Unknown
Selective reporting (reporting bias)	Low risk	No known selective reporting
Other bias	Low risk	No other bias found