FERTILITY AND STERILITY Copyright © 1989 The American Fertility Society Vol. 52, No.1, ,July 1989 Printed in U.S.A. Performance of different embryo transfer catheters in a human in vitro fertilization program* Michel Camus, M.D. Paul Devroey, M.D. Arjoko Wisanto, M.D.t Ronny Janssens, M.T. Johan Deschacht, M.D. Andre C. Van Steirteghem, M.D., Ph.D. Center for Reproductive Medicine, Academic Hospital Vrije Universiteit Brussel, Brussels, Belgium In a prospective and randomized study on 400 consecutive embryo transfers (ETs), the performance of three different transfer catheters was evaluated. In cases of difficult ET, the TDT catheter (Prodimed, Neuilly-en-Thelle, France) performed the best. However, the pregnancy rate with this catheter was the lowest (9.2%/ET). A better pregnancy rate (19.4%/ET) can be achieved when TDT catheter was used under ultrasound guidance. The Frydman catheter (Prodimed, Neuilly-en-Thelle, France) yielded the highest preg- nancy rate (32.3%/ET) but also the highest frequency of difficult transfer procedures. The Wallace catheter (H. G. Wallace Limited, Colchester, England) showed similar per- formance, but the pregnancy rate was lower (19.2%/ET) compared with the Frydman catheter. Therefore, the Frydman catheter is used as the first choice, and for difficult transfers the TDT catheter under ultrasound guidance can be recommended. Fertil Steril 52:79,1989 Several papers have been published showing different factors that influence the results of hu- man in vitro fertilization (IVF) and embryo trans- fer (ET).1-3 Although every step in the IVF-ET procedure is important, few investigators exam- ined so far the role of the ET procedure on the out- come of IVF -ET. The degree of difficulty of the ET was related to the outcome of IVF-ET.l,4 To date, the transcervical route of embryo replacement is most commonly used. To enhance the pregnancy rate, several groups recently reported other meth- ods and new devices for ET. 5 - 7 In order to find the most suitable catheter for hu- man embryo replacement in our IVF -ET program, between July 1987 and March 1988, a controlled Received November 23,1988; revised and accepted March 14, 1989. * Supported by grant 3.0036.85 from the Belgian Fund for Scientific Medical Research. t Reprint requests: Arjoko Wisanto, M.D., Center for Repro- ductive Medicine, Academic Hospital Vrije Universiteit Brus- sel, Laarbeeklaan 101, B-1090, Brussels, Belgium. Vol. 52, No.1, July 1989 study was set up to compare the performance of three different ET catheters as well as the ultra- sound-guided transfer procedure with the TDT catheter. We examined the ease of embryo replace- ment, the eventual traumatic effects, and the preg- nancy rate. Furthermore, the three catheters were investigated for possible embryotoxic effect in a mouse embryo culture system. MATERIALS AND METHODS Between July 1987 and March 1988, 400 ET pro- cedures were performed in our IVF -ET program at the Center for Reproductive Medicine of the Vrije Universiteit Brussel. On a prospective and ran- domized manner, these human ETs were carried out using: a Frydman catheter (Prodimed, Neuilly- en-TheIle, France), a Wallace catheter (H. G. Wal- lace Limited, Colchester, England), or a TDT cath- eter (Prodimed, Neuilly-en-Thelle, France) with or without ultrasound guidance. The performance of these disposable catheters during ET were com- Wisanto et al. Embryo transfer catheters in IVF-ET 79