morning sickness

Morning sickness is nausea or vomiting during the first 20 weeks of pregnancy. More than half of pregnant women have morning sickness during the first trimester. It usually goes away by the second trimester. When morning sickness is severe, it is called hyperemesis gravidarum.

 

The cause of morning sickness is not well understood, but hormones seem to be involved. The hormone called human chorionic gonadotropin, or HCG, is produced by the fertilized egg and by the chorionic villi. These are the fingerlike projections of the developing placenta. HCG is needed to keep the pregnancy going until the placenta has developed enough. HCG levels are usually highest in the first 12 weeks of pregnancy.

 

There is a huge variation in severity of morning sickness symptoms. Some women just feel queasy in the morning and feel fine by noontime. They are able to perform their daily activities. Others suffer from nausea and vomiting that can last all day. They find ordinary work during pregnancy almost impossible.

 

Some women have symptoms of morning sickness within days of conception. The average time from the last menstrual period to the start of nausea is about 5 weeks.

 

The symptoms of morning sickness include:

 

A woman with levels of HCG that are higher than usual for her stage of pregnancy is more likely to have morning sickness. High levels of HCG are seen in multiple pregnancies, such as twins and triplets. A woman who has had morning sickness in a previous pregnancy is more likely to have it again.

Morning sickness cannot always be prevented. Some women find diet and lifestyle changes helpful in reducing symptoms. The mother is advised to avoid things that produce the symptoms, such as certain foods and smells. She should eat smaller, more frequent meals. Dry crackers or toast, tea, cold liquids, and carbonated drinks may help reduce morning sickness. Eating before getting out of bed may help prevent the nausea.

Diagnosis of morning sickness begins with a history and physical exam. Urinalysis may be done, as well as blood tests to check for dehydration.