What is the cause of nausea and vomiting in pregnancy?
It is not entirely clear what causes morning nausea and the vomiting that often accompanies it. The common hypothesis is that the cause for this phenomenon lies in the placenta. Therefore, morning sickness is more severe in cases of a twins pregnancy, i.e. when there are two placentas for two fetuses in the womb. Another fact to support this hypothesis is that morning sickness is harder for women with an exceptionally large placenta.
Additional factors that may affect nausea and vomiting during pregnancy are: a genetic disposition, i.e. the mother experienced nausea and vomiting during pregnancy, Hyepremesis Gravidarum during the current or previous pregnancy and carrying a female fetus.
In addition, high level of hormones during pregnancy may cause a slowing down of the digestion processes. This may cause conditions such as heart burn, reflux (Gastroesophageal reflux disease, a condition where food “rises” back from the stomach to the esophagus), a digestive disorder that may cause nausea and vomiting. Moreover, an infection in the intestines caused by the bacteria Helicobacter Pylori may worsen or be manifested by morning sickness. However, it is important to emphasize that this infection is not always found in pregnant women who suffer from morning sickness.