Technical aspects of embryo transfer: a literature review

Assisted reproductive technologies (ART) aim to address the underlying causes of infertility, resulting in a healthy live birth. One aspect that appears receiving less attention yet is equally crucial as any other steps in the ART process, is embryo transfer (ET). Even with optimal embryos, a successful live birth cannot be achieved without a precise and atraumatic transfer to the correct location within the uterine cavity. Compared to other advancements in laboratory and clinic, relatively few innovations have occurred in ET.

This literature review aimed to summarize the latest evidence in four main sections: requirements and preparations for ET, the ET procedure, complications, training and competence.

The review emphasizes the need for appropriate equipment, including soft-tip catheters and high-resolution ultrasound machines, to minimize trauma and enhance ET precision. Additionally, rigorous quality control in the laboratory is essential for achieving optimal clinical outcomes. Despite the technical simplicity of ET, complications such as cervical trauma, retained embryos, and rare expulsion from the cervix highlight the need for further research and improvement in this critical step of the process. Finally, the necessity for well-trained practitioners and embryologists, with competence regularly evaluated through performance indicators, is crucial.

Further research is needed to standardize ET techniques and improve ART outcomes, suggesting that each step of ET may significantly influence the procedure's success. Attention to detail and adherence to key factors are critical to optimizing the transfer of an embryo to the uterus, leading to higher pregnancy rates and better patient outcomes.