Fetal heart monitoring does not pass at least once and then needs to be reassessed after oxygen administration. If the fetal heart monitor passes after one oxygen intake, consider the fetal sleep period and don’t worry too much; if the review after oxygen intake doesn’t pass, you also need to rule out intrauterine hypoxia. 1. Fetal sleep period: with the increase of gestational weeks, fetal sleep will have a certain pattern, if the fetal heart rate monitoring is performed when the fetus is sleeping, the fetal heart rate monitoring may not pass. For this situation, do not worry too much, can be treated with oxygen, most of the time again to review, fetal heart monitoring can pass. 2. Fetal intrauterine hypoxia: Fetal hypoxia may occur due to umbilical cord around the neck, placental oxygen supply abnormality, placental abruption, amniotic fluid contamination, pregnant women’s physical abnormalities, etc. If the fetal heart rate monitoring still fails to pass after oxygen intake, this case needs to improve the ultrasound of obstetrics in a timely manner, to understand the situation of the fetus, the placenta and the amniotic fluid, and hospitalization if necessary. If the fetal heart rate does not pass, it is important to follow the doctor’s instruction to recheck the fetal heart rate after oxygen intake. At the same time, if accompanied by other discomforts, you also need to inform the doctor in time to help determine the disease. Hospitalization, if necessary, to avoid delays.