Cicek 2012

Methods	Randomised controlled trial
Participants	Women with a diagnosis of unexplained infertility undergoing ovulation induction and IUI (n = 107) Inclusion criteria: no ovulatory problems, normal hysterosalpingography and laparoscopy. Normal semen sample Exclusion criteria: endometriosis, hypertension, diabetes, uterine myoma, ovarian cyst, excessive alcohol, caffeine, chronic illness and smoking
Interventions	1. Vitamin E: 400 IU: one tablet per day from 3rd to 5th day of the menstrual cycle until the hCG injection. (n = 53) 2. No treatment (n = 50) 4 women were lost to follow‐up as a result of incorrect dose consumption (n = 3) and cycle cancellation (n = 1). ITT not used in the trial
Outcomes	Primary outcome: ongoing pregnancy rate Secondary outcomes: biochemical and clinical pregnancy rate, number of follicles, endometrium thickness, implantation rate
Notes	Study was conducted between June 2011 and December 2011 in Turkey Sample size calculated Ethics approved and written consent obtained Funding not reported, but authors say they have no conflict of interest Emailed author 9th August 2012 regarding the number of women lost from treatment and/or control group. Data added. Will perform sensitivity analysis for quality if we do not hear back from the author regarding ITT. No reply
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Randomly assigned according to a randomisation table
Allocation concealment (selection bias)	Unclear risk	No mention of allocation concealment
Blinding (performance bias and detection bias) All outcomes	High risk	Not blinded as the control was no treatment
Incomplete outcome data (attrition bias) All outcomes	High risk	Reasons and numbers for attrition were given but unclear whether from treatment or control groups. ITT not used
Selective reporting (reporting bias)	Low risk	Nil known
Other bias	Low risk	No other bias found