High fever refers to a body temperature of more than 39 ℃, so when a pregnant woman has a fever with a temperature of 38.3 ℃, it is not a high fever. Body temperature of 38.1-39 ℃ is moderate fever, body temperature higher than 39 ℃ lower than 41 ℃ is high fever. Pregnant women with a temperature of 38.3℃ are considered to have a moderate fever, which is mainly caused by infectious factors, such as pneumonia, urinary tract infection, acute gastroenteritis and so on. When fever occurs, if not actively treated will make the fetus abnormal, so it should be actively dealt with. When a pregnant woman has a fever of 38.3℃, it is recommended to lower the temperature physically and go to the hospital for a complete examination to clarify the cause of the fever, and choose a safe and effective treatment that minimizes the impact on the fetus under the guidance of the doctor, so as to prevent delays in the condition.