Level 1: Causes of nosebleeds in pregnant women There are many causes of nosebleeds in pregnant women. Common ones include dryness of the nasal cavity, dilation of blood vessels in the nose, nasal infection, and excessive forceful blowing of the nose. In addition, pregnant women are also prone to nasal congestion and edema due to changes in hormonal levels during pregnancy, which can lead to nosebleeds. Level 2: How to prevent nosebleeds in pregnant women. To prevent nosebleeds in pregnant women, you can start from the following aspects. head