Level 1: Causes of fever in pregnant women There are many causes of fever in pregnant women, the most common of which are fevers caused by respiratory infections such as colds and flu. In addition, fever may be caused by other diseases, such as pneumonia, urinary tract infection, etc. In addition, pregnant women are prone to being attacked by bacteria and viruses due to their weakened immunity, which can lead to fever. Level 2: The impact of fever in pregnant women on the fetus. Fever in pregnant women will have certain effects on the fetus. High temperatures can cause hypoxia in the fetus