Early Supraspinal Influences on Human Embryonic Posture.

Knowledge of embryonic body posture as a reflection of neurodevelopment is limited. Here, we investigate embryonic body posture, preference, symmetry, and lateralization during periods of rest using virtual reality (VR) and four-dimensional (4D) ultrasound techniques to enhance our knowledge of neurodevelopment. It is hypothesized that lateralization and asymmetry in embryonic posture are absent. Embryos from low-risk pregnancies at 9 weeks gestational age (GA) were analyzed using a 30-min 4D ultrasound and VR techniques. In the middle of an embryonic resting period, the total body posture was determined by combining joint positions. Interindividual and intraindividual postures were analyzed over time to identify posture preferences, asymmetry, and lateralization. Sixteen embryos (N = 210 middle frames out of 210 resting periods) displayed 27 different embryonic body postures. Interindividual and intraindividual variations in postures were seen. Asymmetry was noted in upper extremities, whereas lateralization of the head and spine was observed in nine embryos. Intraindividual and interindividual variation in embryonic posture at 9 weeks' GA is seen, suggesting the presence of supraspinal influences on body posture this early. Future interdisciplinary longitudinal studies on embryonic posture may provide further insights into embryonic central nervous system development, contributing to our understanding of embryonic health.

Evaluation of embryonic posture using four-dimensional ultrasound and virtual reality.

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.