Tucker 1996.

Study characteristics
Methods	Single‐centre randomised trial
Participants	100 women from North America undergoing ICSI Mean age: control group 33.5 (4.3); AH group 35.3 (4.2)
Interventions	AH with acid Tyrode's (chemical; complete zona breach; 72 hour egg retrieval to AH; 4 hour AH to transfer) vs no AH AH: 50 women randomised, 189 embryos transferred Control: 50 women randomised, 184 embryos transferred
Outcomes	Implantation, clinical pregnancy
Notes	Attempted to contact author about this study; no reply received ET: AH 3.7, control 3.8 Unclear whether power calculation performed ITT analysis unclear
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Randomisation stated but method unclear or incorrect
Allocation concealment (selection bias)	Unclear risk	Allocation concealment unclear
Blinding (performance bias and detection bias) All outcomes	Unclear risk	Participants not blinded or unclear Assessor not blinded or unclear
Incomplete outcome data (attrition bias) All outcomes	Low risk	Women randomised appear to be analysed
Selective reporting (reporting bias)	Unclear risk	Original protocol not viewed but study authors did not report on live birth
Other bias	Low risk	None identified