1. Causes of Nose Bleeding in Pregnant Women There are many causes of nose bleeding in pregnant women, and the common ones are as follows: 1. Hormonal changes: Changes in hormonal levels in pregnant women can cause the blood vessels in the nasal mucosa to dilate, causing nose bleeding. 2. Dry air: Dry air in winter and indoor heating will dry out the nasal mucosa and easily lead to nose bleeding. 3. Nose injury: Pregnant women accidentally touching their nose in daily life or blowing their nose with a tissue that is too strong may cause nose injury and bleeding.