Morning sickness: what helps, and when it needs treatment

Pregnancy sickness can come at any time of day

Nausea and vomiting are symptoms of early pregnancy that affect most women. The usual name is “morning sickness”, but the nausea can come at any hour of the day or night.

Some women feel sick for a short time each day and vomit once or twice; others feel sick for hours and vomit often.

Weeks of sickness can affect mood, work and home life. If you feel low or anxious, tell your doctor or midwife.

More on this: Antenatal & Postnatal Care →

It usually starts by week 7 and eases by weeks 16 to 20

Pregnancy sickness usually begins between the 4th and 7th week of pregnancy, and tends to be at its worst around week 9.

NICE describes mild to moderate nausea and vomiting as likely to settle before 16 to 20 weeks. In some women it lasts longer, and in a few it continues until the birth.

There is no need to wait until it is severe. The UK’s Royal College of Obstetricians and Gynaecologists (RCOG) advises seeing a doctor if symptoms do not settle or stop you doing your daily activities.

Eating little and often, sipping fluids and resting can ease milder sickness

Most women manage pregnancy sickness themselves. These measures can ease milder sickness, but none of them stops it, and they are not enough when vomiting is frequent.

• Eat small amounts often, so that your stomach is never empty.
• Choose foods high in carbohydrate and low in fat, such as rice or pasta, and avoid the foods and smells that set off your nausea.
• Eat something plain, such as dry toast or a plain biscuit, in the morning.
• Try cold food instead of hot if the smell of hot meals brings on the nausea.
• Sip fluids through the day, as dehydration can make nausea worse.
• Rest when you can.

For mild to moderate nausea, NICE suggests trying ginger if you prefer not to start with a medicine. The RCOG guideline reports little or no effect in hyperemesis gravidarum, where many women who tried it had unpleasant effects and felt worse, so it should not delay treatment.

Acupressure is steady pressure on a point on the inner wrist. NICE says it can be considered alongside usual treatment for moderate to severe sickness. That benefit was not shown in milder sickness, and it does not replace fluids or medicine.

Anti-sickness medicines are an option, and the choice is made with your doctor

When these measures are not enough, a doctor can prescribe an anti-sickness medicine. NICE asks doctors to discuss the advantages and disadvantages of each with you. The RCOG guideline says the benefits of these medicines outweigh the risks, and the doctor weighs both in your case.

• Antihistamine-type medicines, such as cyclizine or promethazine, are usually tried before the others. They have been used in pregnancy for many years, and the available evidence does not suggest a higher chance of birth defects. Studies of how well they work are limited, and they can cause drowsiness.
• Metoclopramide relieved nausea and vomiting in high-quality studies. It can cause restlessness, trembling or muscle spasms, so it is usually a later choice, given for short periods.
• Ondansetron is usually kept for sickness that other medicines have not controlled. Some studies link its use in early pregnancy with a small increase in the chance of a cleft lip or palate, and it can cause constipation.
• Vitamin B6 (pyridoxine): ACOG lists it as a treatment that may be tried before others, alone or together with doxylamine, and the RCOG leaflet names a prescription tablet that combines the two as a licensed treatment for pregnancy sickness in the UK. Like the others, it is taken on your doctor’s advice.

If one medicine does not help or its side effects are hard to live with, another can usually be tried.

Do not start, stop or combine these medicines on your own because of what you read here. The choice and the dose are decided with your doctor.

Hyperemesis gravidarum is severe sickness that prevents normal eating and drinking

Hyperemesis gravidarum is the severe form of pregnancy sickness. It begins before 16 weeks, and the nausea or vomiting is bad enough that a woman cannot eat and drink normally or carry on with daily life. Dehydration and weight loss can follow.

Treatment usually begins with fluids through a drip, where possible as day care without an overnight stay. Anti-sickness medicine is given by injection or through the drip. Vitamin B1 (thiamine) is added because a lack of it can cause a serious brain condition; it does not ease the nausea itself.

Admission to hospital is considered when vomiting continues despite this or weight keeps falling.

Hospital treatment has drawbacks of its own. A drip can be uncomfortable and the vein can become sore. Dehydration and time in bed raise the chance of a blood clot in the leg or lung, so heparin injections are offered, and these can leave bruises. The medicines carry the side effects described above. Treatment controls the illness without removing its cause, so symptoms can return and some women need treating more than once.

No evidence that mild to moderate sickness harms the baby; severe sickness is watched closely

The RCOG’s information for patients states that there is no evidence that mild to moderate nausea and vomiting have a harmful effect on the baby. ACOG, its American counterpart, says pregnancy sickness usually does not harm the baby.

Women with severe sickness or hyperemesis gravidarum may have a baby with a lower birthweight than expected, so scans may be offered to follow the baby’s growth.

In the RCOG’s words, hyperemesis gravidarum that is not treated may cause more harm to the baby than any possible effects of a medicine recommended by your doctor.

Sickness that starts late or comes with other symptoms is checked for another cause

A doctor looks for another cause when vomiting begins only after 16 weeks, or when it comes with symptoms that pregnancy sickness does not usually bring, such as abdominal pain, pain on passing urine, fever or headache.

The conditions considered include a urine infection, a stomach ulcer, gallstones and thyroid disease. A urine test and blood tests are the usual starting point.