Pregnancy is a happy process, but at the same time it is also a risky period, and many pregnant mothers are both happy and scared, afraid of whether their baby is safe in the womb, but whether the baby will come successfully. Pregnancy is a long process, which means that fetal development is also a long process. Checking the health of the fetus is mainly to check whether the baby’s development in the womb is in accordance with the gestational week, and whether there are deformities in the fetal development, as well as the condition of the amniotic fluid and umbilical cord. In the early stage of pregnancy, the fetus has just started to develop, and the fetal heartbeat can be seen through ultrasound. As the fetus has not differentiated into limbs and extremities during this period, it is normal as long as there is no abdominal pain and abnormal vaginal bleeding. In the 11-13+6 weeks of pregnancy, ultrasound is needed to check fetal NT, which is the posterior nuchal translucency layer, an early screening for fetal anomalies; in the 16-20 weeks of pregnancy, pregnant women need to have blood sampling to check for fetal chromosomal abnormalities and neural tube abnormalities, which is commonly known as Down screening, if the age is older than 35 years old or if the risk of Down screening is high, it is recommended that pregnant mothers have non-invasive DNA testing or amniocentesis if conditions allow; in the 18-24 weeks of pregnancy, pregnant mothers need to undergo ultrasound to check for fetal chromosomal abnormalities and neural tube abnormalities. The best time is 20-24 weeks, if done too early, the corresponding fetal organs will not be well developed, if done too late, the fetal activity will be limited and some parts may be obscured; if there is no obvious abnormality in the previous screening, it can be done at 24-28 weeks. If there is no significant abnormality in the previous screening, you can have a fetal heart ultrasound at 24-28 weeks to check whether there is any abnormality in the fetal heart structure, and then follow the doctor’s instruction to have regular maternity checkups to ensure the safety of the baby in the womb and continue the detoxification, waiting for the baby to come.