Calf circumferences in fetuses and neonates with and without talipes equinovares. A prospective cohort study.

Objective: Children and adults with talipes equinovarus (TEV) have smaller calves and shorter feet compared to non-affected controls. Do these changes have a prenatal onset?
Methods: A prospective cohort study (January 2020-July 2021) was conducted with serial ultrasonographic measurements at 20 and 28 weeks gestation and measurements directly and 6 weeks after birth. Calf circumference and width, foot length and length of humerus, ulna, radius, femur, tibia and fibula were measured in TEV and were compared to a control population. Calculated sample size necessitated a minimal population of 10 cases with TEV and 50 controls.
Results: Twenty cases with TEV and 62 controls were included. Fetal calf circumference (p < 0.001) and width (p < 0.001) were smaller in the TEV group in comparison to the control group, which persisted after birth. Growth in foot length (p < 0.001) and calf width (p 0.003) declined prenatally over time. The bone lengths and upper leg circumference were not smaller or shorter in TEV compared to controls.
Conclusion: This prospective cohort study demonstrated the prenatal onset of reduced calf and foot size in fetuses with TEV from 20 weeks and onwards, which persists directly after birth. To investigate whether reduction in circumference initiates TEV or is caused by TEV, further examination is needed.
(© 2023 The Authors. Prenatal Diagnosis published by John Wiley & Sons Ltd.)