There is no fixed time for how long a fetus can last in chronic hypoxia, and fetal death can occur at any time. Fetal chronic hypoxia is known as chronic intrauterine distress, which mainly occurs in late pregnancy, the condition can be progressively aggravated, the initial stage can be manifested as an abnormal increase in fetal movement, and thereafter the fetal movement is gradually reduced, further aggravation of the condition can lead to the disappearance of fetal heartbeat and fetal movement, at any time, can lead to fetal demise in the uterus, there is no fixed period of time, how long the fetus can last. When chronic hypoxia occurs in the uterus, pregnant women should actively seek medical treatment to improve the hypoxic state of the fetus, if all kinds of therapeutic measures are ineffective, they should choose to terminate the pregnancy as soon as possible. If there is any abnormality in the labor and delivery examination, the pregnant woman should seek medical treatment in time so as to avoid delaying the condition, which may lead to adverse consequences.