What Causes Nausea Vomiting During Pregnancy

The most common causes of uncomplicated nausea and vomiting during early pregnancy (see table Some Causes of Nausea and Vomiting During Early Pregnancy ) are Morning sickness (most common) Hyperemesis gravidarum Gastroenteritis Occasionally, prenatal vitamin preparations with iron cause nausea. It's thought hormonal changes in the first 12 weeks of pregnancy are probably one of the causes of morning sickness. But you may be more at risk of it if: you're having twins or more; you had severe sickness and vomiting in a previous pregnancy; you tend to get motion sickness (for example, car sick) you have a history of migraine headaches Score: 4.2/5 (73 votes) . The exact cause of nausea and vomiting in pregnancy is not clear. Most evidence points to rapid changes in hormone levels.These fluctuations may cause changes in the muscle contraction and relaxation patterns of your stomach and intestines, thus leading to nausea and vomiting.