Fang 2010.

Study characteristics
Methods	Single‐centre randomised controlled trial
Participants	125 women in China who had their first IVF/ICSI cycles between 2006 and 2008, with fresh IVF‐ET failures or without fresh embryo transfers Mean age: 32.3 in AH group, 32.1 in control group Setting: fertility centre, China (2006 to 2008)
Interventions	Mechanical assisted hatching: expanding/stretching zona pellucida via injected hydrostatic pressure AH: 61 women, 178 embryos Control: 64 women, 190 embryos
Outcomes	Clinical pregnancy, implantation rates
Notes	Unclear whether power calculation performed ITT analysis unclear Published as full paper
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	No details
Allocation concealment (selection bias)	Unclear risk	No details
Blinding (performance bias and detection bias) All outcomes	Unclear risk	Unclear whether participants were blinded
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Unclear
Selective reporting (reporting bias)	Unclear risk	Original protocol not viewed. Live birth not reported, so not sure it was planned
Other bias	Low risk	None identified