Aim: In anatomic studies of the embryo, it has been established that during the development of the lower limb, several changes in foot position can be observed defined as a temporary ‘physiological clubfoot’. The aim of this study was to develop and test a measurement tool for objective documentation of the first trimester foot position in vivo and made an attempt to create a chart for first trimester foot position. Methods: We developed a virtual orthopedic protractor for measuring foot positioning using three-dimensional virtual reality visualization. Three-dimensional ultrasound volumes of 112 pregnancies of women examined during the first trimester were studied in a BARCO I-Space. The frontal angle (plantar flexion) and the lateral angle (adduction) between the leg and foot were measured from 8 until 13 weeks gestational age. Results: We observed that the frontal angle steadily decreases, whereas the lateral angle first increases, resulting in transient physiological clubfeet position at 10- to 11-week gestation, followed by a decrease to a normal foot position. Conclusion: A transient clubfoot position is present during the normal development of the lower limbs, and it has been measured in vivo for the first time. This study emphasizes that a diagnosis of congenital clubfoot should not be made in the first trimester of pregnancy.

clubfoot, pregnancy, prenatal diagnosis, ultrasonography, virtual reality,
Journal of Obstetrics and Gynaecology Research
Department of Gynaecology & Obstetrics

Bogers, H, Rifouna, M.S, Cohen-Overbeek, T.E, Koning, A.H.J, Willemsen, S.P, van der Spek, P.J. (Peter J.), … Steegers, E.A.P. (2018). First trimester physiological development of the fetal foot position using three-dimensional ultrasound in virtual reality. Journal of Obstetrics and Gynaecology Research. doi:10.1111/jog.13862