Development of a Screening Tool for Difficult Embryo Transfers

So far there has never been a screening tool to identify difficult ETs without doing a mock ET. This is a prospective, longitudinal study including at least 200 ETs. All women undergo a speculum examination at the time of transvaginal oocyte pick-up (OPU), the screening questionnaire will be filled by the Physician doing the OPU procedure. On the day of real ET, the Physician doing the ET will be blinded for the screening result, and fill a second questionnaire after the ET. Combined with the Embryologist recorded parameters, this second questionnaire will be used to categorize ETs as difficult or normal. Participants will NOT undergo any procedures beyond their routine treatment. Once the targeted number of participants are recruited, the questionnaires will be matched to see the accuracy of the screening questionnaire to identify difficult ETs.

Identification of difficult ETs with a non-invasive, free of cost questionnaire can enable selective mock transfers and facilitate the real ET for patients, who would otherwise be only recognized on the day of real ET, after their embryos have been already thawed for transfer.

• Oocyte Pick Up (Procedure): The screening questionnaire will be filled by the Physician doing the OPU. The screening questionnaire will be informed by the participant's history. Cervix will be visualized during routine vaginal cleansing for OPU, and its appearance (size, and deviation) will be recorded in the screening questionnaire after the OPU procedure. Finally, a screenshot of the ultrasound used for OPU, showing the cervix and cervical canal in the sagittal plane will be taken during routine procedure and saved in electronic chart.
• Embryo Transfer (Procedure): When the participants comes back for ET during her routine treatment, ET will be done in exactly the same way in routine treatment. Participant will not undergo any additional manipulation, intervention, nor the procedure will take longer. The Embryologist assisting the procedure will record the duration of the procedure, from the moment the Physician takes the outer ET catheter to his/her hand until he/she passes the cervix and calls for the inner catheter loaded with the embryo. Up on completion of the ET procedure as routine practice, the Physician will fill a questionnaire about the procedure.

Primary outcomes

• Prevalence of difficult ET [Approximately 4 months]
• Percentage of screening questionnaires suggesting a difficult ET [Approximately 4 months]
• Accuracy of the screening tool to predict difficult ET [Approximately 4 months]

Sex: Female

Inclusion Criteria:

* All women undergoing an ET is eligible.

Exclusion Criteria:

* No exclusion criteria, women can participate with multiple ET procedures.

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• Results publication: Ata B, Lawrenz B, Melado L, Del Gallego R, Coughlan C, Ruiz F, Marqueta Marques L, El-Damen A, Elkhatib I, Fatemi HM. The ART-ET screening tool: an easy-to-use non-invasive screening method to predict difficult embryo transfers in advance. Hum Reprod. 2025 Apr 1;40(4):647-653. doi: 10.1093/humrep/deaf002. PMID 39938557

• Barbara Lawrenz, PhD, Study director, ART Fertility Clinics LLC