The importance of biparietal diameter measurement to babies. In recent years, with the development of technology, more and more mothers have begun to pay attention to the measurement of their babies\’ head circumference. As an important indicator in head circumference measurement, biparietal diameter is widely used in the medical community. So, what is biparietal diameter? What impact does it have on the baby\’s physical development? This article will elaborate on four aspects. 1. What is biparietal diameter measurement? Biparietal diameter measurement is to measure the baby.