Ge 2008.

Methods	Randomised controlled trial
Participants	760 women from China having IVF with fewer than five failed cycles of ART with normal baseline FSH concentration. Those participants with uterine abnormality or low fertilisation capacity (rate of fertilisation less than 20% and late ICSI following fertilisation failure of IVF) were excluded Mean age: Fresh, 31.08 in AH, 30.44 control; Frozen, 31.84 in AH, 30.66 control
Interventions	Laser thinning to about 50% of the initial ZP thickness AH: 387 women with fresh embryos, 100 women with frozen‐thawed embryos Control: 373 women with fresh embryos, 100 women with frozen‐thawed embryos
Outcomes	Implantation rate, pregnancy rate and live birth
Notes	Unclear if power calculation performed ITT not stated Published as full paper
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Women were randomised according to a randomisation list based on sequential numbers in sealed envelopes
Allocation concealment (selection bias)	Low risk	Both patients and the clinician were blinded to group allocation
Blinding (performance bias and detection bias) All outcomes	Unclear risk	Not stated in the text
Incomplete outcome data (attrition bias) All outcomes	Low risk	Fresh embryo transfer cycles: a total of 831 IVF/ICSI cycles were performed during the study period. Of these, 772 met the inclusion criteria but 12 participants abandoned embryo transfer for various reasons such as avoiding potential risks of ovarian hyperstimulation syndrome Frozen‐thawed embryo transfer: a total of 245 frozen‐thawed cycles were also performed, of which 45 were excluded either because they didn't meet the criteria of the study or embryo transfer was abandoned
Selective reporting (reporting bias)	Unclear risk	Original protocol not viewed