The density test is divided into ultrasonic bone density test and X-ray bone density test. X-ray bone density test will have radiation, which can affect the baby’s development and is not recommended for pregnant women, while there is no radiation in ultrasonic bone density test, and both teenagers and pregnant women can do it without harming their health. There is no need for a bone density test for pregnant women. BMD is a method of checking whether a patient has osteoporosis, and pregnant women in early pregnancy usually do not have significant osteoporosis, so there is no need for the test. After the middle of pregnancy, due to the need of pregnancy to mobilize bone calcium to meet the needs of fetal growth and development, it is easy to show excessive bone calcium loss and osteoporosis, it is necessary to perform BMD test, even if there is no bone mineral density test, pregnant women should supplement calcium in time.