Illustration of B-ultrasound in three months of pregnancy to understand the development of the baby. B-ultrasound in three months of pregnancy is usually called \”NT transparency test\” and is an important prenatal medical examination for pregnant women. At this stage, the fetal organs gradually develop and mature, and structural and functional abnormalities of some key organs can be detected and dealt with promptly through B-ultrasound examination. The following is a detailed explanation of the baby\’s development from four aspects. The development of the baby\’s head and brain: During the third month of pregnancy, the fetus\’ head has gradually taken up half of the fetal volume. The size and shape of the head can affect the child\’s intellectual development. B-ultrasound can measure the head