Modern embryo transfer catheters and pregnancy outcome: a prospective randomized trial

Objective: Embryo transfer (ET) is the final crucial step in IVF treatment. The type of catheter used can affect the pregnancy rate (PR). In this prospective, randomized trial we compared the clinical PR between the Wallace and the Cook K-Jet embryo transfer catheters. Design: Prospective, randomized clinical trial. Setting: A National Health Service Assisted Reproduction Unit. Patient(s): One hundred fifty women undergoing a fresh ET. Age more than 40 years, a high basal FSH, a previous difficult ET, or more than six previous ETs were the exclusion criteria. Intervention(s): Women undergoing a fresh ET were randomized at the time of ET to either the Cook K-Jet or Wallace embryo transfer catheter. The randomization was stratified according to age and the number of previous ETs. Main Outcome Measure(s): Clinical PR. Result(s): There was no significant difference in the clinical PR between the Wallace and the Cook catheters (22/75 [29.3%] and 23/75 [30.6%], relative risk [RR]: 0.96 [95% confidence interval 0.58-1.58]). Conclusion(s): There is no significant difference in the PRs achieved by modern, soft, double-lumen ET catheters. (Fertil Steril (R) 2005;84:996-1000. (c) 2005 by American Society for Reproductive Medicine.)