It is not too late to have a 4D ultrasound macrobiotics test at 25 weeks of pregnancy. 4D ultrasound is usually performed in the middle of pregnancy, that is, at 22-26 weeks of pregnancy. Four-dimensional ultrasound can show the real-time dynamics of the fetus in the uterus and the images of various surface structures of the fetus, there is no radiation and electromagnetic waves and other aspects of radiation, safe, simple and harmless, can be repeated examination, more suitable for fetal malformation screening. The congenital malformations that can be detected by 4D ultrasound mainly include fetal facial malformations (e.g. cleft lip and palate), neurological malformations (e.g. anencephaly, spina bifida), digestive malformations (e.g. intestinal atresia, megacolon), and urinary malformations (e.g. hydrocele, polycystic kidney), etc. It also includes the amount of intrauterine amniotic fluid, and how much amniotic fluid is in the uterus. It also includes the amount of amniotic fluid in the uterus, fetal head position, fetal heartbeat, placental attachment, and umbilical cord wrapping problems. 4D ultrasound can be performed in all trimesters, but the best time is 22-26 weeks of pregnancy, when the fetus has entered the abdominal cavity, all major organs have developed, the amount of amniotic fluid in the uterus is appropriate, and the position of the fetus is easy to change, so it is easy to observe, so as not to miss the diagnosis and misdiagnosis. If there are problems with the fetus, it is recommended to review the 4D ultrasound after 2-3 weeks. The specific time and frequency of 4D ultrasound examination should be completed in regular hospitals under the guidance of doctors, do not decide on your own, so as not to cause adverse consequences.