Nausea and Vomiting in Pregnancy
Over 80% of the pregnant women experience nausea and vomiting especially during first trimester of pregnancy. These symptoms of nausea and vomiting are commonly called as ‘Morning sickness’. But the term ‘Morning Sickness’ is a misnomer as the nausea and vomiting can be triggered at any time during the day. Since each woman is different and each pregnancy is different, the severity of nausea and vomiting in pregnancy will vary from woman to woman. As the Human Chorionic Gonadotropin (hcG) and estrogen hormones start decreasing in body, around the 14th week, the pregnancy nausea also starts to decrease. But for some pregnant women the hcG and estrogen levels remain very high until delivery that may result in nausea and vomiting’s all through pregnancy. This article explains about possible causes of nausea and vomiting during pregnancy.
Causes of Nausea and Vomiting in Pregnancy:
There is no confirmed cause for the nausea and vomiting during pregnancy. Although there are certain theories that relate different physical and hormonal changes occurring in the body and the nausea and the vomiting’s, none of them are proved. The possible causes include:
Human Chorionic Gonadotropin:
This is commonly known as ‘pregnancy hormone’. Human chorionic gonadotropin promotes the maintenance of the corpus luteum during the beginning of pregnancy, causing it to secrete the hormone progesterone, which in turn enriches the uterus with a thick lining of blood vessels and capillaries so that it can sustain the growing fetus. It rises significantly during early pregnancy. Nausea and vomiting’s are also at their peak during early pregnancy. But there is no confirmed relation between Human chorionic gonadotropin and nausea.
Estrogen: Estrogen is the hormone that is essential for fetal maturation during pregnancy. This estrogen also rapidly rises during pregnancy. Some theories relate estrogen rise to the increase in nausea and vomiting’s during early pregnancy although none of them have enough evidence.
Enhanced sensitivity to odors: Most of the pregnant women experience enhanced sensitivity to certain odors especially substances giving out strong odors. This mostly causes nausea, queasiness. Sometimes if the sensitivity is higher, vomiting may happen. Certain aromas trigger gag reflex. A theory relates this increased sensitivity to odors, to increased levels of estrogen during pregnancy.
Gastrointestinal tract sensitivity: A few women have highly sensitive gastrointestinal tracts, which react to the changes in early pregnancy by causing nausea and vomiting’s. Also, some research suggests that women with a stomach bacterium called Helicobacter pylori are more likely to have severe or long-lasting nausea and vomiting. Not all studies confirm this link, though.
Stress: Some researchers have proposed that certain women are psychologically predisposed to having nausea and vomiting during pregnancy as an abnormal response to stress. However, there’s no conclusive evidence to support this theory.
Hence, there is no definite proved cause of nausea and vomiting’s during pregnancy. It can be due to combined changes of hormone levels and other physical changes occurring in pregnancy.