Ravhon 2005

Methods	Parallel randomised controlled trial Prospective participant recruitment Participant sampling unclear Single‐centre trial performed at the Edith Wolfson Medical Center in Holon, Israel Only fresh embryo transfers were included in the study Unclear whether a power calculation was performed Participants were enrolled in the study between July 2004 and November 2004, but the actual length of follow‐up was not reported An intention‐to‐treat analysis was not mentioned in the text, so unclear whether it was performed Unclear whether multiple treatment cycles per participant were included in the study
Participants	148 participants were recruited and randomly assigned to a treatment group of 79 or a control group of 69. No loss to follow‐up was apparent, so the data on all 148 participants were analysed The number of embryos transferred was unclear, for only mean numbers per participant were given Mean age (SD): treatment group 34.8 (5.8), control group 34.3 (5.9) years Causes of subfertility and whether it concerned primary or secondary subfertility not reported Subfertility duration (SD): treatment group 3.9 (4.9) years, control group 3.6 (2.8) years All participants underwent IVF Number of previous cycles (SD): treatment group 4.5 (4.1), control group 5.4 (4.9) No age analysis was performed
Interventions	Fresh embryo transfers in EmbryoGlue (0.5 mg/ml HA) versus fresh transfers in G1 medium (0.125 mg/ml HA) All embryos were cultured in G1 medium Randomisation was performed on day of embryo transfer Exposure time to EmbryoGlue before transfer was not reported Timing of transfer during embryo development was not reported All embryos were fresh, no frozen‐thaw protocol was followed Inclusion of donor oocytes was unclear Culture and transfer media were manufactured by Vitrolife Mean number of embryos transferred per participant: treatment group 2.3 ± 0.8, control group 2.2 ± 0.8 Method of pregnancy determination was not reported
Outcomes	Secondary outcomes Clinical pregnancy rate: reported as a percentage of group size. No further definitions given Additional outcomes Implantation rate: reported as a percentage, but total number of embryos transferred was unclear, so implantation rate cannot be calculated. No further definitions
Notes	Abstract of a ASRM conference presentation.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Participants were randomly allocated to a treatment or a control group, but method of randomisation was unclear
Allocation concealment (selection bias)	Unclear risk	Allocation concealment was unclear
Blinding (performance bias and detection bias) All outcomes	Unclear risk	Unclear whether participants, clinicians and/or scientists were blinded
Incomplete outcome data (attrition bias) All outcomes	High risk	Actual length of follow‐up was unclear. No live births were reported. Loss to follow‐up was not accounted for, and it was unclear whether an intention‐to‐treat analysis was performed
Selective reporting (reporting bias)	Low risk	Clinical pregnancy and implantation rates were reported in a prespecified way
Other bias	High risk	No commercial funding. Same transfer media brand in treatment and control groups. Transfer media were comparable, with the addition of EmbryoGlue to the treatment group. No multiple pregnancy rate was reported, although multiple embryos were transferred per cycle