The effect of embryo transfer technique on pregnancy rates in in vitro fertilization-intracytoplasmic sperm injection cycles: A prospective cohort study

Objective: To investigate whether embryo transfer affects pregnancy rates in in vitro fertilization-intracytoplasmic sperm injection (IVF-ICSI) treatment. Materials and Methods: A total of 2,257 patients who underwent IVF-ICSI treatment between 2012 and 2017 were included in this study. Subjects were categorized according to the embryo transfer technique that was required: group 1 (n=1,657) underwent easy transfer with a soft catheter; group 2 (n=548) received external guidance transfers; and group 3 (n=52) experienced difficult transfers with a stylet. Basal parameters, clinical and laboratory IVF-ICSI outcomes, and clinical pregnancy rates (CPR) were compared between the groups. Results: There were no differences between the groups in terms of age, body mass index, smoking status, duration and etiology of infertility, baseline follicle-stimulating hormone, luteinizing hormone, estradiol (E-2), thyroid-stimulating hormone, prolactin levels, antral follicle count, duration of stimulation, stimulation protocol, total gonadotropin dose required, peak E-2 levels, progesterone levels, and endometrial thickness on human chorionic gonadotropin administration and transfer days (p>0.05). The numbers of oocytes retrieved, MII and 2PN, fertilization rate, day of embryo transfer, and CPRs were also comparable between the groups (p>0.05). Conclusion: Our data suggest that embryo transfer has no impact on pregnancy rates in patients who undergo IVF-ICSI treatment. Further studies with more participants are required to elucidate this situation.