Ultrasound-guided embryo transfer: a prospective randomized controlled trial

BACKGROUND: Recent reports suggested that ultrasound guidance during embryo transfer might improve the pregnancy rate. METHODS: A prospective randomiz ed controlled trial was performed to compare embryo transfer under ultrasou nd guidance versus the clinical touch method. A total of 800 embryo transfe rs was studied; 400 were randomized to ultrasound-guided transfers and 400 were randomized to the clinical touch group. Of these, 441 were fresh cycle s and 359 were frozen-thawed cycles. RESULTS: The clinical pregnancy rate w as 26.0% in the ultrasound-guided group and 22.5% in the clinical touch gro up; the difference was not statistically significant. The ongoing pregnancy rate was 23.5% in the ultrasound-guided group compared with 19.0% in the c linical touch group and the difference was again not statistically signific ant. The implantation rate was slightly higher in the ultrasound-guided gro up (15.3%) than the clinical touch group (12.0%) (P = 0.048). There were no differences in the incidences of ectopic pregnancy, miscarriage and multip le pregnancy between the two groups. CONCLUSIONS: A significant improvement in implantation rate was observed following the use of ultrasound guidance during embryo transfer. The extent of improvement in the pregnancy rate ma y depend on the specific techniques and methods of embryo transfer used in individual centres.