Critical procedural steps in intrauterine transfusion: Delphi survey of international experts.

Objective: To determine consensus, using Delphi methodology, on the critical procedural steps for intravascular intrauterine transfusion (IUT) for the treatment of fetal anemia.

Methods: We conducted a two-part Delphi survey of international experts in fetal intervention. The first round of the survey proposed 32 potentially critical steps for the IUT procedure. Participants were asked to rate all steps on a Likert scale ranging from 1 (not important) to 5 (absolutely essential). We calculated the mean Likert score and 95% CI for all steps. Procedural steps were determined to be critical if the lower bound of the 95% CI was ≥ 3.0 and were excluded if the upper bound of the 95% CI was ≤ 3.5. In the second round of the survey, participants were asked specific questions regarding parameters associated with the procedural steps determined to be critical in the first round.

Results: Overall, 49 individuals from 24 different countries (six continents) participated in both rounds of the Delphi survey. The median length of experience in fetal medicine was 21 (range, 4-38) years. The median number of IUT procedures performed annually per respondent was 20 (range, 2-80). Of the 32 proposed procedural steps, 20 were determined to be critical and 12 non-critical procedural steps were excluded. Respondents indicated that an individual should perform a median of 20 (range, 10-50) IUT procedures during training to attain competency, and that the median number of IUT procedures required annually to maintain competency was 10 (range, 5-20). There was marked variation between respondents in how they performed the following critical IUT procedural steps: preparation of donor blood, preoperative medication, maternal anesthesia, site chosen for cordocentesis, use of fetal paralysis, method for determining fetal hematocrit, postoperative care and decision to schedule a subsequent IUT.

Conclusions: The findings of this international Delphi survey can be used to standardize the approach to performing IUT. An experienced fetal interventionist should perform the procedure, and in centers in which IUT is performed infrequently, referral to a more experienced center should be considered. Calculating the specific volume of blood to transfuse at the start of the procedure and undertaking continuous fetal heart-rate monitoring once the gestational-age threshold for viability is reached were ranked highest in the intra- and postoperative phases of the procedure, respectively. © 2024 International Society of Ultrasound in Obstetrics and Gynecology.