Pannus Assistance Needed for Obstetric Ultrasound Studies

The goal of this randomized controlled trial is to evaluate whether use of a pannus retractor adhesive improves fetal anatomic ultrasound examinations. The primary question it aims to answer is: • Does the use of a pannus retractor adhesive increase the rate of detailed anatomic survey completion, defined by satisfactory visualization of sixteen prespecified fetal anatomy views, for participants with a pannus and body mass index of at least 40 kg/m2?

Pregnancies complicated by obesity have an increased risk of multiple pregnancy complications, including structural fetal anomalies. Ultrasound is a critical tool for the detection of congenital anomalies; however, adequate visualization of fetal anatomy by ultrasound decreases as body mass index increases. Placing a pannus retractor adhesive is a simple intervention that redistributes adiposity, providing better access to an important acoustic window for fetal ultrasound. The investigators will conduct a randomized controlled trial comparing outcomes between groups that undergo fetal anatomy ultrasound examinations with or without use of a pannus retractor adhesive. The adequacy of ultrasound visualization is the primary outcome of interest. Secondary outcomes of interest include sonographer pain perception, participant satisfaction, adequacy of all detailed anatomy views, detection of fetal anomalies, skin to amniotic cavity depth, duration of ultrasound exam, and adverse reactions.

Size of varying blocks used within the permuted block design randomization will be masked to investigators. Efforts will be made to mask the physician who is interpreting the ultrasound from participant allocation; the participant and sonographer will be asked not to disclose the study arm to the interpreting physician, and no ultrasound images that would reveal study group allocation will be saved for the physician's view.

Research team members will apply a pannus retractor adhesive according to manufacturer's directions. The sonographer will be asked to attempt all views of the detailed anatomic survey before the adhesive is removed. If the sonographer thinks that additional views could be obtained with the adhesive removed using transabdominal or transvaginal imaging, this is acceptable based on the pragmatic design of this study.

The detailed anatomic survey will proceed per normal protocol. Approaches may include transabdominal and transvaginal imaging.

traxi® Panniculus Retractor is a disposable adhesive medical device designed for surgical patients with a BMI of at least 30kg/m2, to retract a pannus cephalad and expose the lower abdomen. The device is like a large sticker or bandage, posing no more than minimal risk to participants. The adhesive will be applied to the abdomen according to manufacturer instructions, just prior to a participant's scheduled ultrasound. Once the ultrasound exam has ended, the adhesive will be immediately removed and discarded.

Views including: brain (lateral ventricles, cerebellum, cavum), face, heart (four chamber view, right outflow tract, left outflow tract, three vessel view, three vessel trachea view), spine (cervical, thoracic, lumbar, sacrum, and spine shape will be summarized as one spine view), ventral wall, umbilical cord, stomach, left and right kidneys, and bladder.

A survey will be administered to the sonographer performing the anatomy ultrasound for each participant. The sonographer will be asked to complete the survey immediately after the ultrasound exam. The following questions will be asked with Likert scale responses ranging from strongly disagree to strongly agree: I experienced pain in my arm, shoulder and/or wrist while performing this ultrasound The participant's body habitus affected my ability to complete the ultrasound I feel confident about the quality of ultrasound images obtained The use of a pannus retractor made the ultrasound easier to perform It was easy to apply the pannus retractor

A survey will be administered to the participants immediately after the ultrasound concludes. The following questions will be asked with Likert scale responses ranging from strongly disagree to strongly agree: I felt comfortable during the ultrasound I am satisfied with the quality of ultrasound pictures I received I enjoyed the ultrasound experience today I would be willing to have future ultrasounds performed with the retractor adhesive in place

Views including: calvarium/cranium, intracranial anatomy, cavum, parenchyma, lateral ventricles, choroid plexus, cerebellum/vermis, cisterna magna, midline falx, cervical spine, thoracic spine, lumbar spine, sacral spine, spine shape/curvature, face, lips, neck, nuchal fold, nasal bone, palate, profile, orbits/eyes, mandible, maxilla, thoracic contour, lungs, four chamber view, cardiac activity, cardiac rhythm, cardiac situs, right outflow tract, left outflow tract, aortic arch, ductal arch, SVC, interventricular septum, cardiac axis, diaphragm, three vessel view, three vessel trachea view, IVC, crossing, ventral wall, cord insertion, situs, stomach, gallbladder, left kidney, right kidney, bladder, left humerus, right humerus, left forearm, right forearm, left hand, right hand, left femur, right femur, left lower leg, right lower leg, left foot, right foot, umbilical cord, genitalia.

The ultrasound reports' individual fields and summary will be reviewed to determine if a fetal anomaly was suspected or confirmed during the encounter. The name of the anomaly or anomalies will be recorded.

Using only the minimal amount of pressure to create the image, the shortest mid-sagittal distance will be measured from the skin to the amniotic cavity above and below the pannus. The measure will be repeated for the intervention group once the pannus retractor is in place.

The time from first to last ultrasound image acquisition will be recorded. The time it takes to place the retractor will also be recorded.

In addition to routine monitoring for all adverse effects, the following will be noted specifically: skin irritation, allergic reaction, maternal intolerance of pannus retractor adhesive, fetal demise, and hospital admission immediately following the ultrasound exam.

Inclusion Criteria: English or Spanish speaking BMI of at least 40.0 kg/2, calculated within 6 months of conception or at the first obstetric visit Pannus grade 1 or greater Gestational age between 18 weeks 0 days to 23 weeks 6 days, confirmed by prior ultrasound assessment Exclusion Criteria: Patients who have already had a routinely timed anatomy ultrasound during the same pregnancy with Prisma Health Maternal-Fetal Medicine Patients with a known major fetal anomaly, confirmed by Prisma Health Maternal-Fetal Medicine Tape/adhesive allergy Multifetal gestation Intrauterine fetal demise

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