Sherif 2018.

Study characteristics
Methods	RCT, 2 arms, 60 randomised Setting: Ain‐Shams University Hospital, Egypt ‐ one centre Recruitment period: no description
Participants	Criteria related to previous IVF failure: yes, women with previous failed ICSI were excluded Inclusion criteria :age between 25 and 30 years old, BMI between 20 and 30, Cause of infertility either tubal causes, ovulatory causes, unexplained causes Exclusion criteria: endometriotic patients, Male factor of infertility, Uterine cavity abnormalities, previous failed ICSI, hydrosalpinx and pyosalpinx.
Interventions	Study group: single induced injury was done on the posterior endometrium 1 cm to 2 cm from the fundus by using modified Cook catheter, on day 6 of the ICSI cycle Control group: no procedure
Outcomes	Reported in paper: clinical pregnancy Obtained by author correspondence: ‐
Notes	Trial registration: PACTR201701001968212 (recruitment period unclear however stated to be conducted between 2015‐2017 on trial registry, therefore unclear whether registration was prospective or not but likely retrospective) Additional concerns and comments: none Funding: No description Author correspondence: attempted but no reply received (ahmedsherif@med.asu.edu.eg) Publication: full‐text.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "Randomization was achieved by a computer generated randomization table (Research Randomizer Version 4.0 software)".
Allocation concealment (selection bias)	Unclear risk	No description (trial registration says opaque envelopes used, however this is not described in the paper)
Blinding of participants and personnel (performance bias) All outcomes	High risk	No blinding employed
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Only objective outcomes reported
Incomplete outcome data (attrition bias) All outcomes	Low risk	Appears to be no attrition
Selective reporting (reporting bias)	Unclear risk	All outcomes from trial registration page are reported, but unclear whether registration was prospective
Other bias	High risk	Trial does not appear to have been registered prospectively. There was a significant difference in fertilisation rate in favour of the interventional group 83 (63–100) versus 67 (47–83) in the control group (P = 0.020), which would create bias in favour of the intervention arm.