Difficulty of embryo-transfer (ET) and pregnancy rate based on the uterocervical angle

When the angle formed by the uterine body and cervical axes (uterocervical angle) was less than 115 degrees, a catheter for embryo transfer could not be smoothly inserted into the uterine body, and so a hard catheter was used, which significantly reduced the pregnancy rate and implantation rate. When the uterocervical angle measured before embryo transfer by ultrasonography is less than 115 degrees, careful preparation, such as catheter selection for embryo transfer and the setting of a longer operation time, is necessary.