Aim: To assess the possibility of embryonic posture evaluation (=feasibility, reproducibility, variation) at rest at 9 weeks' (+0–6 days) gestational age (GA) using four-dimensional ultrasound and virtual reality (VR) techniques. Moreover, it is hypothesized that embryonic posture shows variation at the same time point in an uneventful pregnancy. Methods: In this explorative prospective cohort study, 23 pregnant women were recruited from the Rotterdam periconceptional cohort. A transvaginal four-dimensional ultrasound examination of 30 min per pregnancy was performed between 9 and 10 weeks' GA. The acquired datasets were offline evaluated longitudinally (i.e. per frame) using VR techniques. Results: The ultrasound data of 16 (70%) out of 23 pregnancies were eligible for evaluation. At rest the analysis of the embryonic posture was feasible and showed a strong (>80%) intraobserver and interobserver reproducibility for most body parts. The majority of the body parts were in similar anatomic positions at rest. However, variations in anatomic positions (e.g. 6% rotated head, 9% laterally bent spine), within and between embryos, were seen at 9 weeks' GA. Conclusion: In this unique study, we showed for the first time that embryonic posture measurements at rest can be performed in a reliable way using state-of-the-art four-dimensional ultrasound and VR techniques. Already early in prenatal life there are differences regarding posture within and between embryos.

embryonic development, posture, pregnancy trimester, first, ultrasonography, virtual reality,
Journal of Obstetrics and Gynaecology Research
Department of Gynaecology & Obstetrics

Frudiger, A. (Anne), Mulders, A.G.M.G.J, Rousian, M, Plasschaert, S, Koning, A.H.J, Willemsen, S.P, … Steegers, E.A.P. (2020). Evaluation of embryonic posture using four-dimensional ultrasound and virtual reality. Journal of Obstetrics and Gynaecology Research. doi:10.1111/jog.14554