Elhelw 2005.

Methods	Power calculation not reported ITT not stated Published as abstract only
Participants	74 women from Egypt undergoing ICSI only Poor prognosis Previous 2 implantation failures Cryo‐thaw cycles only
Interventions	Laser hatching (thinning to quarter) versus no hatching. AH done 1 hour before embryo transfer AH: 37 women randomised, 121 embryos transferred Control: 37 women randomised, 130 embryos transferred
Outcomes	Implantation rate, clinical pregnancy rate
Notes	No author contact as all details in article No data re no. of embryo transfer
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Not stated, no details
Allocation concealment (selection bias)	High risk	Not used
Blinding (performance bias and detection bias) All outcomes	Unclear risk	Participant blinding unclear Assessor blinding unclear
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	No details
Selective reporting (reporting bias)	High risk	Conference abstract only. No evidence of a full paper. Live birth not reported