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 folliclestimulating 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.