Morning Sickness in Pregnancy: Causes, Home Remedies and When It Is Hyperemesis

Nausea and vomiting in early pregnancy, often called morning sickness, affects up to 70-80% of pregnant women, although it can happen at any time of the day. It is unpleasant and can disrupt work and daily life, but it is usually harmless and temporary. A small number of women develop severe vomiting called hyperemesis gravidarum, which needs medical treatment.

What causes morning sickness?

The exact cause is not clear. Contributing factors include:

• Rapidly rising pregnancy hormones, especially hCG and oestrogen
• A heightened sense of smell and a sensitive stomach
• Slower digestion due to progesterone
• Low blood sugar, tiredness and stress
• Genetics, as it often runs in families
• Twin or molar pregnancy, which can cause more severe symptoms

Timeline

• Starts: around 4-7 weeks of pregnancy
• Peaks: around 8-12 weeks
• Improves: by 14-16 weeks for most women
• Persists: into the second or third trimester in about 1 in 10

Use our due date calculator to see which week you are in.

Self-help measures

• Eat small, frequent meals every 2-3 hours, and avoid an empty stomach. Keep dry biscuits or crackers by your bed and eat a few before getting up.
• Choose bland, cold or room-temperature foods, such as plain rice, rice kanda, toast, banana, curd, boiled potatoes, soups and fruit.
• Avoid triggers: strong smells, greasy, spicy or very sweet foods, cooking odours, and heat. Ask others to cook, or use cold meals.
• Drink fluids in small sips between meals rather than with food: water, ORS, king coconut water, ginger or lime water, diluted juice or ice chips.
• Ginger: ginger tea, ginger biscuits or ginger sweets may help mild nausea. Up to about 1 gram of ginger a day is commonly suggested.
• Acupressure wristbands at the P6 point on the inner wrist help some women, with minimal risk.
• Brush teeth gently and rinse after vomiting to protect the enamel. Wait 30 minutes before brushing.
• Rest well, since tiredness worsens nausea, and avoid sudden movements.
• Fresh air and a cool environment.
• Review your iron or multivitamin tablets. Taking them with food or at night may help. Do not stop folic acid. Ask your doctor about switching or pausing iron in the first trimester.

Medicines

Speak to a doctor before using any medicine. Options sometimes used include:

• Vitamin B6 (pyridoxine) alone or with doxylamine, often the first-line treatment
• Antihistamines such as promethazine or cyclizine
• Metoclopramide, or ondansetron, and other anti-sickness drugs for more severe symptoms
• Intravenous fluids and vitamins in hospital for severe vomiting

Do not use herbal remedies or traditional preparations without medical advice, because some are unsafe in pregnancy.

Hyperemesis gravidarum: the severe form

Seen in about 1-3% of pregnancies, hyperemesis is persistent, severe vomiting. Signs include:

• Vomiting several times a day, unable to keep down food or fluids
• Weight loss of more than 5% of pre-pregnancy weight
• Dehydration: dark urine or very little urine, dry mouth, dizziness, fast heartbeat
• Extreme tiredness, weakness and fainting
• Low mood, anxiety, constant nausea and drooling

It needs prompt treatment, often with IV fluids, vitamins (including thiamine), anti-sickness medicines and sometimes admission to hospital. Untreated, it can cause electrolyte problems, vitamin deficiency and other complications. With treatment, outcomes are good, though it can be distressing and last for weeks.

Seek medical help promptly if

• You cannot keep down any fluids for 24 hours
• You vomit more than 3-4 times a day, or lose weight
• You have dark urine or pass urine only once or twice a day
• You feel dizzy or faint, or have a fast heartbeat
• You have abdominal pain, fever, blood in vomit or yellow skin
• Vomiting starts after 9-10 weeks or has a sudden change in pattern
• You have severe headache or vision changes, especially later in pregnancy

Emotional support

Persistent nausea can be exhausting and isolating. Talk to your partner, family and doctor. Ask for time off work if needed, and do not feel guilty about eating whatever you can tolerate. Reassurance and rest are part of the treatment.

Eating well when you are able

Even if your diet is limited at first, try to return to a balanced diet as soon as you can, with vegetables, fruit, pulses, eggs, fish and dairy. Take folic acid daily, and ask your antenatal clinic about vitamins and iron. Read our guide on early pregnancy symptoms for foods and habits to avoid.

When to see a doctor

Mention nausea and vomiting at your antenatal visit, even if mild. Contact your clinic or hospital the same day if you notice any warning signs above.

References

• American College of Obstetricians and Gynecologists: nausea and vomiting of pregnancy
• Royal College of Obstetricians and Gynaecologists: management of nausea and vomiting in pregnancy and hyperemesis gravidarum
• NICE guideline NG201: antenatal care
• Sri Lanka Ministry of Health, Family Health Bureau: antenatal care guidance