First trimester umbilical cord and vitelline duct measurements using virtual reality

Abstract

Background The umbilical cord and vitelline duct are of vital importance to the fetus, but they are rarely the subject of first trimester two-dimensional (2D) ultrasound evaluation due to the complexity of their shape and morphology. Virtual reality (VR) allows efficient visualisation and measurement of complex structures like the umbilical cord and vitelline duct. Aim To measure normal first trimester human growth of the umbilical cord length (UCL) and vitelline duct length (VDL) using a VR system; and to correlate both measurements with the gestational age (GA) and crown-rump length (CRL) and the VDL with the yolk sac volume (YSV). Study design Prospective cohort study. Serial three-dimensional (3D) ultrasound measurements were performed from six to 14 weeks GA, resulting in 125 3D volumes. These volumes were analysed using an I-Space VR system. Subjects Thirty-two healthy pregnant women with an ongoing, normal pregnancy. Outcome measures The UCL, VDL, YSV and other related structures were measured. Results The UCL, measurable in 55% of cases, was positively correlated to advancing GA and CRL (p < 0.001). The VDL could be measured in 42% of cases and showed a positive relationship with GA and CRL (p < 0.001). There was a significant (p < 0.001) relationship between YSV and VDL. Conclusions The present study, facilitated by a VR system, is the first to provide an in-vivo longitudinal description of normal first trimester growth of the human umbilical cord and vitelline duct. Further studies will reveal whether these parameters can be used in detection of abnormal fetal development.