Level 1: Causes of fever in pregnant women There are many reasons for fever in pregnant women, the most common ones are colds, flu, bacterial infections, etc. In addition, pregnant women are also susceptible to various viruses and bacteria due to their weakened immunity, which can lead to fever. Level 2: Dangers of Fever in Pregnant Women Once a pregnant woman has a fever, it will have certain effects on the fetus. High temperature can cause abnormal fetal neurological and cardiovascular development and increase the risk of premature birth, miscarriage and stillbirth. At the same time, high temperature will also speed up the metabolism of pregnant women, making them prone to dehydration and electrolyte imbalance.