What Causes Morning Sickness in Pregnancy

During the first trimester of pregnancy, most women experience waves of nausea, sometimes accompanied by vomiting. This is more commonly referred to as morning sickness.

The condition is common, and unless very severe, does not pose a threat to the baby. Up to 80% of pregnant women have at least some nausea, and 50% have both nausea and vomiting during pregnancy.

It usually starts around the fifth or sixth week of pregnancy and tends to get worse during the next month or so. Morning sickness does not pose any apparent threat to the baby unless it is extremely severe. It goes away for most women by around 14 to 20 weeks of pregnancy. Of course, some lucky people never experience nausea or vomiting at all.

Morning Sickness Symptoms

Nausea, vomiting, retching (dry heaving) and excessive salivation are all symptoms that indicate morning sickness in a mother-to-be.

The severity and frequency of the symptoms may vary from person to person. For example, some women with morning sickness might feel sick to their stomachs for hours, while others would just be mildly queasy for a short amount of time.

"Morning sickness" is a misleading term. It isn’t imperative that this occurs in the morning only. Some mothers-to-be experience terrible nausea in the morning which then eases up during the latter part of the day, while for some it lasts the entire day, making the early stages of pregnancy an unpleasant experience.

Even a mild case of nausea can stress you down, and repeated bouts of round-the-clock nausea and vomiting can leave you really exhausted.

How Long Does Morning Sickness lasts?

Although not extremely common, few expecting moms could exhibit symptoms of morning sickness even in the second (sometimes third) trimester. Lingering morning sickness may prove to be a hindrance and will leave your mood soiled, and body feeling miserable.

Severe cases may lead to dehydration and deter the body from gaining a healthy amount of weight. If it persists beyond 20 weeks of pregnancy, it is advisable to visit the doctor.

Causes of Morning Sickness

It is still unknown as to what exactly the causes morning sickness, during pregnancy. It is surmised to be due to the many physical changes taking place in the body during this period. Most doctors confirm that it is in fact, a good sign of a healthy pregnancy and that the placenta is developing and forming well. Some of the possible causes include:

1. Human chorionic gonadotropin (hCG) causes Morning Sickness

This hormone rises rapidly during early pregnancy. It is still unclear how hCG contributes to nausea, but it is likely that it does because the feeling of nausea increases whenever there is a spike in the levels of hCG

2. Oestrogen causes Morning Sickness

Along with other hormones, oestrogen is another possible cause because it also rises rapidly in early pregnancy

3. Sensitive stomach causes Morning Sickness

Some women have more sensitive stomachs than others. The presence of Helicobacter pylori bacteria in the digestive tract may also lead to nausea and vomiting. However, studies have not confirmed the link between the two and it is still open to speculation.

4. Genetics causes Morning Sickness

There are two genes involved in placenta development, and they are GDF15 and IGFBP7. These genes have also been linked to hyperemesis gravidarum, which is known to be one of the most severe forms of morning sickness. It is said that women with these genes have extremely high levels of proteins and the only way to treat their morning sickness would be to figure out a way to lower the protein levels.

5. Sugar Levels causes Morning Sickness

This is not proved yet but is assumed that placental development depletes sugar levels in a body and in turn result in the morning sickness in a pregnant woman

6. Enhanced sense of smell causes Morning Sickness

Pregnant women are usually sensitive to smell. Certain aromas may trigger their gag reflexes. It is speculated that this may be due to upsurge in the levels of oestrogen. This sensitivity is theorised to be protective. It is a stimulus that helps safeguard the mother from toxins and poisons in the environment and also helps keep the baby safe.

7. Stress causes Morning Sickness

Nausea and heightened senses of smell can be because of increased levels of stress during pregnancy. It needs to be kept in mind that although the rise in stress levels do contribute to changes in the body during pregnancy, scientists have not been able to fully establish this as a concrete cause for morning sickness.