Mucus Removal Before Embryo Transfer (MUCRET)

EFFICACY STUDY OF THE UTILIZATION OF A FLUSHING CATHETER FOR REMOVAL OF CERVICAL MUCUS BEFORE AN EMBRYO TRANSFER: A RANDOMIZED PILOT CONTROLLED TRIAL

Despite these revolutionary changes in the laboratory, little has changed with the process of embryo transfer (ET). A study to prospectively evaluate the role of cervical mucus removal prior to embryo transfer on pregnancy rates in ART will be undertaken.

ET involves placing the embryo(s) obtained before assisted reproduction technology (ART) into the uterus via a catheter advanced through the cervical canal. Yet this is the final, and in some respects the most critical, process in the sequential events that encompass an ART cycle. If an embryo cannot be delivered to the uterine cavity atraumatically and in a location for optimal implantation, the steps of ovarian hyperstimulation, oocyte retrieval, embryo culture, and embryo selection will have no benefit. Contamination of the catheter with blood may be a marker for difficult ET and has also been linked to poor ET outcomes. When retrospectively assessing outcomes, Goudas et al. (1) demonstrated a clinical pregnancy rate of 50% with no blood, and this rate fell by half when a small amount of blood was noted on the catheter tip. Pregnancy rates fell even further, to 10%, when there was a significant amount of blood (1). Similarly, in a preliminary study, blood or mucus on the tip was associated with a significantly lower pregnancy outcome (2). Blood and mucus were associated with an increased risk for unsuccessful transfers with odds ratios of 1.9 and 1.8, respectively. Although all these data suggest a possible role of cervical mucus in embryo transfer, there is no clinical evidence on the effect of removal of cervical mucus on the outcome of IVF/ICSI. In view of this uncertainty, a study to prospectively evaluate the role of cervical mucus removal prior to embryo transfer on pregnancy rates in ART will be undertaken. It is hypothesized that removal of cervical mucus will achieve higher clinical pregnancy rates.

All participants will be randomized by an intention to treat approach. All other components of the IVF/ICSI cycle including stimulation medications, monitoring protocols, etc. will be at the discretion of the participant's primary physician; while this information will be documented it will not constitute criteria for enrolment. The group allocation will take place the day of the embryo transfer. The clinician will randomize all included patients into one of the two study groups using an open computer-generated list.

Embryo transfer will be performed as per clinic's routine protocol, where cervical mucus is gently removed with a cotton swab. No manipulation of the cervical canal is executed.

A catheter will be used to perform a flushing of the cervical canal with culture media. The Flushing Catheter has a flared proximal end that is designed to affix to a standard Luer slip syringe and a pre-curved distal closed end, with a biseled opening on the side, 2mm from the tip, in which liquid flushes towards the outside of the cervical canal. Device: Cook Flushing Catheter J-IUIC-352200 (3.5fr 20cm flushing catheter with positioner closed end) (CEE approval).

Defined as the proportion of patients with a pregnancy loss following a positive pregnancy test and/or a detectable gestational sac

Inclusion Criteria: IVF or OD patients with supernumerary embryos (oocyte's age will be considered as patient's age). Normal transvaginal ultrasound at screening, without evidence of clinically significant abnormality consistent with finding adequate for ART with respect to uterus and adnexa Single embryo transfer Embryo transfer at the blastocyst stage Embryo with a morphological classification of ≥3BB Exclusion Criteria: Preimplantation genetic diagnosis and/or screening