Level 1: Causes and harms of low blood pressure in pregnant women Low blood pressure in pregnant women may be caused by factors such as increased metabolic rate, increased blood volume, and increased cardiac output during pregnancy. Hypotension will affect the fetal oxygen supply and nutrition. In severe cases, it can cause symptoms such as syncope, dizziness, and sweating, and even endanger the health of the mother and baby. Level 2: Maternal Blood Pressure