Staessen 2008.

Study characteristics
Methods	Study design: randomised controlled trial Duration and location of the trial: between October 2004 and December 2006 in the University Hospital, Dutch‐speaking Brussels Free University Sample size: 240 women randomised
Participants	Inclusion criteria: women below 36 years of age Exclusion criteria: patients with an abnormal karyotype or non‐motile sperm were excluded
Interventions	Type of biopsy: cleavage stage biopsy Genetic analysis: genetic analysis with FISH analysis
Outcomes	live birth rate Miscarriage rate Ongoing pregnancy rate Clinical pregnancy rate Multiple pregnancy rate Proportion of women reaching embryo transfer Mean number of embryos per transfer
Notes	Treatment procedure: ICSI only Embryo transfer policy: ICSI only. Single embryo transfer Note: study recruitment was terminated prematurely on basis of interim analysis
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Judgement comment: randomised ‐ no details
Allocation concealment (selection bias)	Unclear risk	Judgement comment: concealment of allocation not reported
Blinding of participants and personnel (performance bias) All outcomes	High risk	Judgement comment: clinicians and embryologists who performed the embryo transfer were blinded only with respect to the patients' participation in the study
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Judgement comment: non‐blinding not likely to affect objective outcomes
Incomplete outcome data (attrition bias) All outcomes	High risk	Judgement comment: data on dropouts not reported
Selective reporting (reporting bias)	Low risk	Judgement comment: no suggestion of selective reporting
Other bias	Low risk	Judgement comment: no suggestion of other bias Funding: grant from the Belgium Fund for Scientific Research Flanders (FWO‐Vlaanderen)