Morning Sickness

The Facts

Many pregnant people (up to 85%) experience a period of nausea and vomiting. In the vast majority of cases, it's unpleasant but not dangerous.

About 2% of expectant parents will vomit so severely that they lose weight and become dehydrated, requiring hospital treatment. This severe form of morning sickness is called hyperemesis gravidarum. Although this condition could be life-threatening if left untreated, it can be remedied by treatment during a brief hospital stay.

When a person has morning sickness, it can be severe enough that it affects usual daily activities (e.g., working, caring for children). Although it's called "morning sickness," the nausea and vomiting may occur at any time of day.

The Causes

While the exact causes of morning sickness aren't known, it's probably linked to pregnancy hormones. People who suffer morning sickness tend to have higher levels of these hormones than those who don't.

It's possible that nausea and vomiting during pregnancy is an ancient mechanism for protecting the fetus from poisons. With the enormously rich and varied diet we eat today compared to our ancestors, it's no surprise that such a protective system could become a bit confused and start rejecting all sorts of healthy food.

One piece of evidence for this idea can be found in research showing that people who suffer from vomiting during pregnancy actually have lower rates of miscarriage than those who don't. Research shows higher levels of 2 hormones (thyroxine and human chorionic gonadotropin) in people with morning sickness. Higher levels of estrogen are found in people suffering from hyperemesis gravidarum.

Other possible causes of morning sickness include infection of the digestive tract and the use of prenatal multivitamins containing iron.

People who suffer nausea from the birth control pill, motion sickness, and migraines are more likely to develop morning sickness during pregnancy.

Symptoms And Complications

Morning sickness doesn't necessarily strike in the morning. While vomiting is at its worst for many people between 9 am and noon, it can continue through the day, or may even appear on a completely different schedule. Vomiting is more likely after meals.

This is essentially a problem of early pregnancy. Some people begin vomiting within days of conception, but typically morning sickness starts about 6 weeks after the end of the last menstruation. Actual vomiting is often preceded by nausea lasting a week or 2.

About 80% of sufferers will feel better by Week 12 of the pregnancy, and most will stop vomiting by the end of Week 16. Occasionally, some nausea returns just before delivery. Like morning sickness itself, this is in no way a dangerous or bad sign. A very few people have morning sickness throughout pregnancy – again, this is unfortunate but not dangerous.

Hyperemesis gravidarum is essentially morning sickness so severe that it affects the birth parent's nutrition and, therefore, the baby's health. It usually leads to dehydration and can also lead to liver or kidney damage. Fortunately, most pregnant people are closely monitored by their doctors, and these complications are almost always caught early on.

You should see a doctor right away if your nausea and vomiting is accompanied by abdominal pain, fever, a fast heartbeat, dizziness when standing, or if your vomit contains blood.

Making A Diagnosis

Morning sickness isn't a disease and doesn't need elaborate diagnostic tests. If a person is pregnant and is throwing up (or constantly feels like throwing up), a doctor will probably tell them that they have morning sickness. It's still morning sickness if they’re only throwing up in the evenings or at other times during the day. A doctor may ask if the pregnant person also has abdominal pain, fever, or other warning signs for further evaluation.

No matter how severe the vomiting, a person is only diagnosed with hyperemesis gravidarum if they are losing weight or showing signs of severe dehydration.

Treatment And Prevention

The best way to manage morning sickness is to start with non-drug measures. Here are some suggestions that many women have found to help:

try snacking or "grazing" throughout the day instead of eating large meals
avoid rich and fatty foods – try plain carbohydrates like potatoes and rice
try soups, jelly, colas and other sodas, and sugared herbal teas
eat a few crackers while in bed before getting up in the morning
carry salted crackers or some similar food around – it's important not to let the stomach get completely empty, as this can increase nausea
drink or sip cold, clear and carbonated or sour fluids in small amounts between meals
try to avoid things that trigger nausea, like certain food smells
if taking prenatal vitamins containing iron, try switching brands to see if symptoms grow milder
avoid prenatal vitamins and take folic acid only
avoid cooking if the cooking odour worsens your symptoms
avoid acidic foods
avoid fried foods
do not lie down right after eating
brush teeth or rinse mouth after eating

There are other suggestions floating around in the media and on the Internet. You should talk to your doctor before trying herbal or vitamin-based remedies. Many people recommend the herb ginger, but its safety and effectiveness have not been proven in scientific studies.

Some people use acupressure, a fairly common home remedy for nausea. The standard device is an elastic wristband with a button on it. The button is placed over the Neiguan point, about 2 inches above the inner wrist. Compressing this point is considered by many to relieve nausea, and ship passengers hoping to avoid seasickness often wear these devices. However, the devices have not been well studied for morning sickness.

If non-drug measures are ineffective, a doctor may prescribe vitamin B6 (pyridoxine) or a combination of doxylamine and vitamin B6 to control morning sickness.* Many people are concerned about taking medications during pregnancy due to the possible risk to the fetus and birth defects. It is important to keep in mind that all pregnant people have about a 3% chance of having a child with a birth defect. Studies have shown that doxylamine-vitamin B6 does not pose a risk to the fetus and is not associated with an increase in birth defects.

People with more moderate to severe cases of morning sickness may be prescribed other anti-nausea medications from the doctor, such as promethazine, prochlorperazine, and chlorpromazine*. People with hyperemesis gravidarum may also need to receive intravenous (IV) feeding or fluid replacement to treat dehydration.