Batioglu 2012

Methods	Randomised controlled trial
Participants	Women with primary infertility between 20 and 40 years undergoing IVF (n = 85) Inclusion criteria: regular menstruation, no hormonal or non‐hormonal drug therapy for less than 3 months and no systemic illness Exclusion criteria: serious endometriosis, serious male factor (azoospermia) hypogonadism with an FSH level < 13. Also participants with cycles cancelled were excluded.
Interventions	1. Melatonin 3 mg: 1 tablet a day (n = 40) 2. No treatment (n = 45).
Outcomes	Primary outcome: number of morphologically mature oocytes retrieved (Mll oocytes) Secondary outcome: fertilisation rate, embryo quality and pregnancy rate
Notes	No information on miscarriage numbers Funding sources not mentioned Clinical pregnancy data (not chemical) used in the meta‐analysis Trial held in Turkey, study dates not reported
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Randomisation computer‐assisted 1:1.
Allocation concealment (selection bias)	Unclear risk	No mention of allocation concealment
Blinding (performance bias and detection bias) All outcomes	High risk	Embyologist was the only person blinded
Incomplete outcome data (attrition bias) All outcomes	Low risk	ITT used. No dropouts were reported
Selective reporting (reporting bias)	High risk	Unclear why chemical pregnancy numbers are lower than clinical pregnancy numbers
Other bias	Low risk	No other bias found