Ultrasound-guided soft catheter embryo transfer: factors influencing pregnancy rates in IVF

There is a growing body of evidence to suggest that die standard technique for embryo transfer (ET) is inadequate. The aim of this prospective, descriptive, noncomparative study was to investigate if there are factors detectable during transabdominal ultrasound-guided ET influencing the results of in vitro fertilization (IVF) and ICSI. For statistic evaluation chi(2) test was used. Methods: In 678 consecutive patients who were undergoing ET the influence of patient's age, transferring person, fresh or frozen-thawed embryos, quality of transfer, quality of catheter visualisation and influence of "jet" phenomenon was evaluated. Results: The use of ultrasound monitoring (using retrospective data) resulted immediately in lower variation in pregnancy rates both in fresh and frozen ET cycles compared to the old "clinical touch" technique (29.3 +/- 2 vs. 24.0 +/- 3.78). In our prospective study age is a factor significantly (p<0.001) influencing the embryo transfer results (PR/ET 36.7% in age group <30, PR/ET 16.8% in age group >38) while using the standardized technique of ultrasound guided ET the influence of transferring person can be eliminated. There was no significant difference in tranfers of fresh (PR/ET 32.7%) or frozen-thawed (PR/ET 26,9%) embryos. Surprisingly, there was also no difference in quality of the transfer procedure and in the quality of echodense catheter tip visualisation. On the other hand if "jet phenomenon" could be observed significantly better results (p=0.033) were obtained (31:3% vs. 20.2%). Conclusions: The use of ultrasound-guided COOK Soft EchoTip catheter may provide less traumatic and more precise embryo placement. Its use contributed to less variations in pregnancy rates both in fresh and frozen-thawed embryo transfers and the influence of transferring person could be eliminated. Factors influencing the results are patient's age and the observation of "jet" phenomenon. Using this technique we were not able to confine the influence of quality of the transfer procedure and the quality of echodense catheter tip visualisation on the achieved results. (C) 2004 Elsevier B.V. All rights reserved.