Valojerdi 2010.

Methods	Single centre, randomised trial
Participants	400 women in Iran undergoing first treatment cycle and women with previous failed cycles Mean age: control group 29.85 (5.14); AH group 30.86 (5.82); 82
Interventions	Partially thinned by laser AH: 200 women randomised Control: 200 women randomised
Outcomes	Clinical pregnancy, implantation rates
Notes	Power calculation not reported ITT analysis unclear
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Randomisation list participants
Allocation concealment (selection bias)	Low risk	Sequential numbers in sealed envelopes (200 participants in each group)
Blinding (performance bias and detection bias) All outcomes	Unclear risk	Unclear
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Not stated
Selective reporting (reporting bias)	Unclear risk	Original protocol was not viewed but authors did not report on live birth

AH = assisted hatching 
 IVF = in vitro fertilisation 
 ICSI = intracytoplasmic sperm injection 
 ITT = intention‐to‐treat 
 Mean age given in years (standard deviation). 
 Note: only arms where all or no embryos transferred were treated with AH were accepted for data extraction.

ET= embryo transfer