Tucker 1993.

Study characteristics
Methods	Single‐centre randomised trial
Participants	218 women from North America undergoing IVF (mean basal FSH: control group 9.0 (5.3); AH group 8.8 (3.7) IU/L) Mean age: control group 34.2 (4.1); AH group 34.1 (4.8)
Interventions	AH with acid Tyrode's thinning to 1/4; 72 hour egg retrieval to AH; 1 to 3 hour AH to transfer) vs no AH AH: 110 women randomised, 333 embryos transferred Control: 108 women randomised, 312 embryos transferred
Outcomes	Implantation, clinical pregnancy
Notes	Attempted to contact author about this study; no reply received ET: AH 2.9, control 3.0 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	Randomisation stated but method unclear or incorrect
Allocation concealment (selection bias)	Unclear risk	Unclear; no details
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	Unclear risk	ITT analysis unclear
Selective reporting (reporting bias)	High risk	Original protocol not viewed but study authors did not report on live birth
Other bias	Low risk	None identified