Objective: To investigate the influence of transfer distance from the fundus on clinical pregnancy rate and implantation rate in in vitro fertilization and embryo transfer.
Methods: A total of 98 patients (108 cycles) undergoing ultrasound-guided embryo transfer were divided into two groups according to the distance between the tip of catheter and the uterine fundus: group A: > or = 5 - < 10 mm, group B: > or = 10 - < or = 15 mm.
Results: Clinical pregnancy rate and implantation rate were significantly higher in group B compared with group A [44 % (23/52) vs 25% (14/56), 24% (28/115) vs 14% (17/121), P < 0.05]. The multiple pregnancy rate, ectopic rate and miscarriage rate were similar in the two groups (P > 0.05).
Conclusion: The depth of the embryo replacement into the uterine cavity may influence pregnancy rate and implantation rate.