Evidence and consensus on technical aspects of embryo transfer

Abstract

BACKGROUND Ultrasound-guided embryo transfer (US-GET) is a widely performed procedure, but standards for the best practice are not available. OBJECTIVE AND RATIONALE This document aims to provide an overview of technical aspects of US-GET after considering the published data and including the preparation for the embryo transfer (ET) procedure, the actual procedure, the post-procedure care, associated pathologies, complications and risks, quality assurance and practitioners’ performance. SEARCH METHODS A literature search for evidence on key aspects of the ET procedure was carried out from database inception to November 2021. Selected papers (n = 359) relevant to the topic were analysed by the authors. The following key points were considered in the papers: whether ultrasound (US) practice standards were explained, to what extent the ET technique was described and whether complications or incidents and how to prevent such events were reported. In the end, 89 papers could be used to support the recommendations in this document, which focused on transabdominal US-GET. OUTCOMES The relevant papers found in the literature search were included in the current document and described according to the topic in three main sections: requirements and preparations prior to ET, the ET procedure, and training and competence for ET. Recommendations are provided on preparations prior to ET, equipment and materials, ET technique, possible risks and complications, training and competence. Specific aspects of the laboratory procedures are covered, in particular the different loading techniques and their potential impact on the final outcomes. Potential future developments and research priorities regarding the ET technique are also outlined. LIMITATIONS, REASONS FOR CAUTION Many topics were not covered in the literature review and some recommendations were based on expert opinions and are not necessarily evidence based. WIDER IMPLICATIONS ET is the last procedural step in an ART treatment and is a crucial step toward achieving a pregnancy and live birth. The current paper set out to bring together the recent developments considering all aspects of ET, especially emphasizing US quality imaging. There are still many questions needing answers, and these can be subject of future research. STUDY FUNDING/COMPETING INTEREST(S) No funding. ADA has received royalties from CRC Press and personal honorarium from Cook, Ferring and Cooper Surgical. The other co-authors have no conflicts of interest to declare that are relevant to the content of this article.

The impact of difficult embryo transfer on the success of IVF: a systematic review and meta-analysis

“…The American Society for Reproductive Medicine (ASRM) guidelines describe better pregnancy rates with several measures, such as the use of abdominal ultrasound during the transfer, the removal of cervical mucus, the use of a soft catheter and the deposition of the embryo at about 1–2 cm from the uterine fundus 2 . Recently, D’Angelo et al 3 provided for ESHRE (European Society of Human Reproduction and Embryology) an overview of technical aspects of ET, including the preparation prior to ET, the procedure itself, the post-procedure care, and the importance of the physicians’ performance. Their recommendation overall overlap with those of the ASRM.…”

“…The procedure of embryo transfer (ET) is unanimously claimed to be crucial for the success of IVF 1 . The procedure should be guided by ultrasound, soft catheters should be preferred, and the embryos should be released at about 1–2 cm from the fundus of the uterus 1 – 3 . There is also evidence suggesting that concomitant administration of hyaluronic acid (HA), Granulocyte Colony Stimulating Factor (G-CSF), human Chorionic Gonadotropin (hCG), or atosiban may improve the success rate, but the effectiveness of these add-ons remains debated 1 , 4 .…”

A retrospective comparative study of double cleavage-stage embryo transfer versus single blastocyst in frozen-thawed cycles

“…However, at the time of writing this paper, there are no guidelines or consensus on blastocyst and cleavage-stage transfers. There is a 2022 consensus on embryo transfer, but the publication was focused on technical aspects before, during, and after the procedure [8]. Several studies have examined the clinical outcomes of the blastocyst-stage transfer but a 2022 Cochrane review concluded that more evidence was needed to determine the impact of the stage of transfer on cumulative live births and pregnancy rates [9].…”

Factors Affecting the Outcomes of First in vitro Fertilization and Embryo Transfer: A Retrospective Investigation

“…These factors include the difficulty of embryo transfer, the appearance of blood or mucus, embryo retention, high uterine contraction frequency, the catheter type, catheter loading and placement techniques, ultrasound quality, and operator-related factors. 4 , 5 In order to standardize ET technique, the American Society of Reproductive Medicine (ASRM) guideline recommends using ultrasound guidance and a soft catheter during the procedure, as well as advocates for early ambulation after the procedure. 6 However, minimal attention has been paid to the embryo transfer technique, as embryo transfer is sometimes seen as an insignificant contributor to the outcome of an IVF cycle; furthermore, physicians are usually unwilling to update their routines or methods for performing embryo transfer.…”