Evaluation of First-Trimester Physiological Midgut Herniation Using Three-Dimensional Ultrasound

The aim of this study was to investigate the development of midgut herniation in vivo using three-dimensional (3D) ultrasonographic volume and distance measurements and to create reference data for physiological midgut herniation in ongoing pregnancies in a tertiary hospital population.

The transvaginal 3D ultrasound volumes of 112 women, seen weekly during the first trimester of pregnancy, were obtained and subsequently analysed in a virtual reality environment. The width of the umbilical cord insertion, the maximum diameter of the umbilical cord, and the volume of midgut herniation were measured from 6 until 13 weeks gestational age (GA).

All parameters had a positive relation with GA, crown-rump length, and abdominal circumference. In approximately 1 of 10 volumes no midgut herniation could be observed at 9 and 10 weeks GA. In 5.0% of the fetuses the presence of midgut herniation could still be visualised at 12 weeks GA.

Reference charts for several dimensions of physiological midgut herniation were created. In the future, our data might be used as a reference in the first trimester for comparison in case of a suspected pathological omphalocele.