A Randomized Trial Evaluating Coconut Oil as an Alternative to Commercial Ultrasound Gel in Obstetrical Ultrasounds

After receiving institutional review board approval, we conducted a randomized 2x2 crossover study. Patients could be enrolled in the study if they had a singleton pregnancy and were presenting for a routine growth or anatomy ultrasound. Exclusion criteria included an allergy to coconut, active inflammatory dermatologic conditions, and a multiple gestation pregnancy. A single ultrasound machine (GE Voluson E10) was used to obtain all images during this study. The three standard fetal biometry views - biparietal diameter (BPD)/head circumference (HC), abdominal circumference (AC), and femur length (FL) - were obtained by qualified ultrasound technicians for each patient with both coupling agents, for a total of six study images per patient. After obtaining written consent, study data were collected and managed using REDCap electronic data capture tools. REDCap (Research Electronic Data Capture) is a secure, web-based application designed to support data capture for research studies, providing: 1) an intuitive interface for validated data entry; 2) audit trails for tracking data manipulation and export procedures; 3) automated export procedures for seamless data downloads to common statistical packages; and 4) procedures for importing data from external sources.

Patients were randomized to either starting their scheduled ultrasound exam by obtaining the three study images using coconut oil and then proceeding with the standard ultrasound using commercial ultrasound gel or vice versa. A total of 15g of room-temperature, organic, refined coconut oil was used for each patient. The commercial ultrasound gel used for this study was room-temperature Aquasonic 100 (Parker Laboratories, Inc., Fairfield, NJ) of an unmeasured amount. The patient's abdomen was cleaned off with a towel between applications of each coupling agent. After completion of the ultrasound session, patient satisfaction with both coupling agents was assessed using a ten-question acceptability survey measured on a five-point Likert scale which was adapted from a previously validated survey.

Using a quantifiable scale developed for this study (0-25: unacceptable, 26-50: suboptimal, 51-75: acceptable, and 76-100: optimal), two experienced Maternal-Fetal Medicine physicians rated all study images on quality, resolution, and detail as defined by prior studies2. Quality was defined as an overall assessment of the image encompassing contrast of solid and fluid-filled structures. Resolution was defined as the sharpness and crispness of the image as well as a lack of haziness/blurriness. Detail was defined as the clarity of landmarks and ease with which boundaries of structures are seen and how well they are defined. Using Viewpoint (GE Healthcare), an ultrasound viewing software, the six study images for each patient were presented in the order of coupling agent each patient was randomized to first and second. Each set of three images per coupling agent was in the following order: BPD/HC, AC, and FL. The physicians rating the images were blinded to the agent used to capture each image and had no knowledge of the randomization list created by the study statisticians.