What causes nausea and vomiting in pregnancy?
Many pregnant women experience nausea in response to specific odours. They may develop aversions to certain foods. Some scientists think that nausea and vomiting in pregnancy may be nature’s way of protecting the baby – it makes the woman stay away from substances that could be harmful to the pregnancy. The high levels of hormones circulating in the pregnant woman’s body are thought to contribute to nausea and vomiting during pregnancy. In the first 12 weeks of pregnancy, a hormone called human chorionic gonadotropin (hCG) builds up in the woman’s body and is excreted in her urine. This is the hormone that is tested to determine whether a woman is pregnant. There appears to be a relationship between the level of hCG and the intensity of a woman’s nausea; they both tend to peak around the same time in pregnancy. Nausea and vomiting may also be associated with problems in the mother’s gastrointestinal tract, or infection with a bacterium known as Helicobacter pylori. Nausea and vomiting
