Validity of trans-rectal ultrasound-guided embryo transfer against retroflexed uterus

Background:  Embryo transfer is one of the most critical steps affecting the success of in vitro fertilization/intracytoplasmic sperm injection-embryo transfer. It has been reported that uterine contraction caused by touching the uterine fundus at the time of embryo transfer decreased the pregnancy rate. It was demonstrated that there is a significant rise in the pregnancy rate by adequate positioning of embryos. Transabdominal ultrasound-guided embryo transfer has been reported to improve the pregnancy rate compared with the clinical touch method. The improvement of the pregnancy rate under ultrasound guidance can be attributed to the accurate positioning of the embryos aided by good visualization without touching the uterine fundus. However, sometimes difficulties are encountered when visualizing the tip of the catheter in cases where the patient has a retroflexed uterus. Methods:  In the present study, we investigated the difference in the pregnancy rates and in the implantation rates between transabdominal ultrasound-guided group and trans-rectal ultrasound-guided group in retroflexed cases. Results and Conclusion:  We found that the pregnancy rate and the implantation rate were higher among the trans-rectal group compared with the transabdominal group in retroflexed cases. The difference between the two groups was statistically significant. (Reprod Med Biol 2003; 2: 159-163).