Morning sickness, also known as nausea gravidarum, nausea/vomiting of pregnancy (NVP), emesis gravidarum, and pregnancy sickness is a condition that affects around 80 percent of all pregnant females.
The woman feels nauseous, sometimes vomits, and is often tired. Women who use hormonal contraception or HRT (hormone replacement therapy) may also have symptoms similar to morning sickness.
In this article, we will discuss why morning sickness occurs, when it is likely to subside, and how it can be effectively treated to reduce symptoms.
Contents of this article:
Fast facts on morning sickness
Here are some key points about morning sickness. More detail and supporting information is in the main article.
- Morning sickness can occur at any time of the day
- The exact causes are still not known
- There are a number of home remedies that can help treat the symptoms of morning sickness
- A small amount of evidence suggests that ginger might ease the nausea
- Morning sickness may be a sign of a healthy pregnancy
What is morning sickness?
Morning sickness is most common during the first trimester of pregnancy.
Despite its name, morning sickness can come on at any time of day. The nausea may be mild, or severe enough to induce vomiting.
When symptoms are very severe, the condition is called hyperemesis gravidarum, which develops in approximately 1-2 percent of all pregnancies.
If nausea and vomiting does occur, it usually starts during the 6th week of pregnancy. For many women, the symptoms of morning sickness are their first signs of pregnancy.
Most pregnant women find that morning sickness improves after the 12th week of pregnancy. Unfortunately, for some, symptoms persist throughout the entire pregnancy.
In the vast majority of cases, morning sickness, although an unpleasant experience, has no health risk for the baby and is a normal part of pregnancy. In fact, some studies indicate that morning sickness during pregnancy can be a sign of a healthy pregnancy, with lower rates of miscarriages and stillbirths, compared with pregnancies with no nausea or vomiting.
Some dietary changes and getting plenty of rest are usually all that is needed to treat morning sickness. Although viewed romantically and humorously, morning sickness can seriously affect the mother's quality of life and how she goes about her daily activities. Women who receive support from family and friends tend to cope much better.
Symptoms of morning sickness
Morning sickness may include nausea and vomiting, or just nausea without vomiting. It is much more common during the first trimester of pregnancy.
Pregnant women should call their doctor if:
- Symptoms of nausea or vomiting are severe
- They pass only a small amount of urine
- Their urine is a dark color
- They cannot keep liquids down
- They feel dizzy when they stand up
- They faint when they stand up
- Their heart races
- They vomit blood
Causes of morning sickness
The exact causes of morning sickness are still not known; however, most agree that hormonal changes probably play a role.
- Estrogen levels - experts believe it might be partly due to an increase in the circulating level of estrogen, which can be 100 times higher during pregnancy, compared with levels found in women who are not pregnant. However, there is no evidence to show a difference in estrogen levels between pregnant women with morning sickness and those without.
- Progesterone levels - when a woman is pregnant, her levels of progesterone also rise. High levels of progesterone relax the uterus (womb) muscles to prevent early childbirth. However, it may also relax the stomach and intestines, resulting in excess stomach acids and GERD (gastroesophageal reflux disease, or acid reflux).
- Hypoglycemia - low blood sugar, caused by the placenta draining energy from the mother's body. However, there are no studies to prove this.
- Human chorionic gonadotropin (hCG) - this hormone is first produced by the developing embryo soon after conception and then later by the placenta. Some experts suggest there may be a link between hCG and morning sickness.
- Sense of smell - during pregnancy, there may be an increase in sensitivity to odors, which might overstimulate normal nausea triggers.
- Evolutionary survival adaptation - some experts suggest that morning sickness could be an evolutionary adaptation that protects pregnant mothers and their babies from food poisoning. If the woman with morning sickness does not feel like eating foods which may be potentially contaminated, such as poultry, eggs, or meat, and prefers foods with a low contamination risk, such as rice, bread, and crackers, the survival chances for her and her child are improved.
Adult humans have defenses against plant toxins, including a wide range of detoxification enzymes produced by the liver. In the developing baby, these defenses are not yet fully developed, and even relatively small amounts of toxins could be harmful.
The baby's developing organs are most vulnerable to toxins between 6-18 weeks, more or less the time when morning sickness peaks.
As a woman's immune system is suppressed during pregnancy (probably so that her body does not reject the baby), this evolutionary survival adaptation is also thought to protect the mother.
If morning sickness is a defense mechanism against the ingestion of harmful toxins, some experts suggest that prescribing anti-nausea medication to pregnant women may not be a good idea. In areas of the world where the mother has access to high-quality foods (with a low risk of contamination), the risk is probably small.
Risk factors for morning sickness
Any woman who is pregnant has the potential for developing morning sickness. However, the risk is higher if:
- Before the pregnancy, the woman had experienced nausea or vomiting from motion sickness, migraines, some tastes or smells, or birth control pills
- The woman had experienced morning sickness in a previous pregnancy
- The woman is expecting more than one baby
Diagnosing morning sickness
Diagnosis of morning sickness is usually a straightforward question of identifying the hallmark symptoms. If hyperemesis gravidarum is suspected, the doctor may order various urine and blood tests. An ultrasound scan might also be done to confirm the number of fetuses and to look out for any underlying conditions that could contribute to the nausea and vomiting.
If ketone levels in the urine are found to be high, it is possible that the vomiting is causing the mother to become malnourished.
Treatment options for morning sickness
For most cases of morning sickness, treatment by a doctor is not necessary. However, there are a number of things that might alleviate symptoms. A full list of these can be found in our article top tips to minimize morning sickness. However, here are a few ideas:
- Rest - tiredness can make the nausea worse. Getting plenty of rest is vital.
- Liquids - fluid intake should be regular and in small amounts, rather than less often and in large amounts. This may help reduce vomiting. Sucking ice cubes made from water or fruit juice or trying lollipops can help.
- Food - consuming more meals per day, in smaller quantities may help, especially high-carbohydrate meals. Dry and savory foods, such as crackers or crispbread are usually better tolerated than sweet or spicy foods. Cold meals are often better tolerated than hot ones (they have less odor).
- Stomach - pregnant women with morning sickness should try to avoid having an empty stomach.
- Early morning - many women find that eating plain biscuits about 20 minutes before getting up helps.
- Triggers - it does not take long to identify nausea triggers. Avoiding them helps reduce the frequency and severity of nausea and vomiting.
Ginger is commonly used to relieve nausea and vomiting, often in the form of ginger lozenges or candies.
Medical treatment - if symptoms are still severe, despite attempting self-care measures, the doctor may recommend a short course of anti-sickness medication (anti-emetic) which is safe to use during pregnancy.
Ginger supplement - some studies have shown that ginger supplement may help reduce nausea symptoms during pregnancy. Women should purchase this from a reputable source.
B-6 and doxylamine - this combination is sold over the counter as Unisom SleepTabs. It has been recommended by the American College of Obstetricians and Gynecologists for treating morning sickness during the first trimester.
Diclegis - this drug is FDA-approved for use by pregnant women. One clinical trial found that Diclegis completely relieved nausea in 44 percent of women with morning sickness. Another study found that more than 70 percent of women reported improvements in symptoms.
Acupressure - this is the application of pressure on specific points on the body to control symptoms. It involves wearing a special band (sometimes called a sea-band) on the forearm. Some limited evidence suggests that this may help improve nausea and vomiting symptoms in pregnant women, although large-scale trials are lacking.
Complications of morning sickness
Hyperemesis gravidarum is a very rare but severe form of morning sickness which is thought to affect about 1-2 percent of all pregnant women. In 90 percent of hyperemesis gravidarum cases, symptoms go away by the fifth month of pregnancy.
Typically, the woman cannot keep fluids down because of severe vomiting. There is a serious risk of dehydration and weight loss. There is also a risk of alkalosis (a dangerous drop in the normal acidity of the blood) and hypokalemia (low blood potassium). Women with severe symptoms should seek medical help immediately. In some cases, hospitalization and treatment with intravenous fluids may be necessary.
If a woman has hyperemesis gravidarum, the chances of causing harm to the baby are very small. If she experiences weight loss during pregnancy, there is an increased risk of giving birth to a baby of low birth weight.