Is TCD a reliable marker for fetal dating in obstetrics ultrasound?
Fetal biometry plays a crucial role in estimating gestational age (GA) and monitoring fetal growth. Traditionally, parameters like biparietal diameter (BPD), head circumference (HC), femur length (FL), and abdominal circumference (AC) have been widely used. However, transcerebellar diameter (TCD) is emerging as a more reliable marker , especially in cases of abnormal growth patterns. But is TCD truly superior for fetal dating? Let’s explore the science behind it. Why TCD is a Reliable Marker for Gestational Age TCD measures the width of the cerebellum in the posterior fossa of the fetal brain. Studies have shown that cerebellar growth follows a linear pattern throughout pregnancy, making it a consistent and reliable marker for dating pregnancies. Key Advantages of TCD for Gestational Age Estimation 1. Less Affected by Fetal Growth Abnormalities Traditional measurements like AC and FL can be significantly affected by intrauterine growth restriction (IUGR), skeletal dysplasias, or macro...