A randomized study of transcervical intrafallopian transfer of pronucleate embryos controlled by ultrasound versus intrauterine transfer of four- to eight-cell embryos

Objective To establish the value of transcervical intrafallopian transfer of zygotes and the accuracy of fallopian cannulation. Design A prospective randomized study, comparing ultrasonically controlled transcervical intrafallopian transfer of zygotes with intrauterine transfer of cleaved embryos. Setting Department of IVF of the Rotterdam Academic Hospital. Patients One hundred forty-five patients with patent tubes entered the IVF program. Main Outcome Measure Pregnancy rates in both groups and ultrasound (US) assessment during fallopian cannulation and ET. Results Transvaginal cannulation of the tube appears not to be sufficiently accurate when performed without US guidance. Catheter damage occurred in many cases. The previously reported superior implantation rate after intrafallopian transfer in comparison with intrauterine transfer could not be confirmed. Conclusions Intrauterine transfer of cleaved embryos remains the method of choice in IVF.