A misnomer! The name given to this condition is really misleading. A lot of women will definitely agree with this statement, most especially soon-to-be moms. Fact is, morning sickness not only occurs in the morning. For many women, it does afflict them during the morning, but it can affect also pose great discomfort at any given time of the day. For some expectant mothers, it can even be an "all-day-everyday" sickness.

Around half to two thirds of all pregnant women will experience morning sickness to some extent, particularly in the first trimester. It is associated with varying degrees of nausea and vomiting. For most women, morning sickness begins around the fourth week of pregnancy and resolves by the 12th week. However, one in five women endure morning sickness into their second semester, and an unfortunate few experience nausea and vomiting for the entire duration of their pregnancy. Morning sickness is typically at its worst early in the day, hence its name, but it can strike at any point during the day or night. Despite research, the actual cause remains a mystery, but theories include hormonal changes and fluctuations in blood pressure. In most cases, morning sickness doesn’t harm the woman or the unborn child. However, severe morning sickness that includes weight loss and dehydration needs prompt medical attention.

Morning sickness is caused by the rapid hormonal changes a woman's body undergoes during pregnancy. This is especially hard during the first few months while a pregnant woman slowly adjust to the hormonal change. This is why many women experience less morning sickness after their first trimester.

The hormonal changes include increasing estrogen, progesterone and hCG (human chorionic gonadotropinis) levels. The hCG is made by cells that form the placenta, which nourishes the egg after it has been fertilized and becomes attached to the uterine wall. Combine this with an enhanced sense of smell and more stomach acid than usual and it’s no wonder women get sick to their stomach during pregnancy.

According to studies, it’s not completely clear how these hormones cause morning sickness, but there are a few theories that have been generally accepted by the medical community. Progesterone tends to soften and relax muscle tissue --- which is the natural process of preparing a pregnant woman's body for labor and delivery. It may also prevent pre-term labor by keeping the uterine muscles relaxed. Unfortunately it also relaxes all the muscles involved in the digestive process, which causes food to be processed slower, thus causing excess stomach acid.

So far no one seems to know why hCG levels may cause morning sickness, but it is believed that there is some connection, simply because morning sickness seems to get worse as hCG levels go up in the beginning of pregnancy. They start to decline around the end of the first trimester, which is also the time when many women notice their morning sickness gradually improve as well.

Pregnant women are also concerned that constant vomiting may threaten their unborn baby. Vomiting and stretching may strain the abdominal muscles and cause localized aching and soreness, but the physical mechanics of vomiting won’t harm the baby. The fetus is perfectly cushioned inside its sac of amniotic fluid. In fact, numerous studies have discovered that moderate morning sickness is associated with a reduced risk of miscarriage. However, prolonged vomiting eventually leads to dehydration and weight loss, a situation which could possibly deprive the child of proper nutrition and increase the risk of the baby being underweight at birth.

Unrelenting morning sickness can have a profound effect on a woman’s quality of life, preventing her from working, socializing and looking after her other children. Pregnant women enduring morning sickness report higher levels of psychological stress, including anxiety and depression. This prompted the fallacy that morning sickness is purely psychosomatic, which means that the woman’s fears and anxieties trigger her physical discomfort. However, there is no research to further substantiate these claims.

Nevertheless, morning or "all-day-everyday" sickness, the most important thing is always seek medical advice, especially if symptoms become severe. Treatment options can include drugs that won’t harm the developing baby.