During early pregnancy, it is common to experience nausea and vomiting. This is often referred to as "morning sickness" but symptoms can occur at any time of the day.
Morning sickness affects 70% to 80% of pregnant women. Symptoms usually begin 4–6 weeks after your last period and peak between 9 and 16 weeks. In 9 out of 10 women, symptoms disappear by 22 weeks gestation (the end of the first trimester). Up to 10% of women continue to have symptoms until their baby is born.
Normal morning sickness won't threaten your baby's health as long as you are able to keep food down, eat a well-balanced diet and drink plenty of fluids. However, if you are pregnant and experience nausea and vomiting that is severe and ongoing, you should see your midwife or doctor.
What are symptoms of morning sickness?
Symptoms can occur at any time of the day and often include:
- dry retching (like vomiting, but nothing is thrown up)
- food smell or sight sensitivity (certain smells or the sight of some foods can trigger nausea).
Not all women experience morning sickness in the same way.
- Some women have only occasional queasy moments while others feel nauseous and sick almost constantly but never vomit.
- Some women vomit now and again, while others vomit more frequently and feel better afterwards.
- In some women, the nausea and vomiting are severe and ongoing. They are unable to keep down fluids or food, causing them to lose weight and become dehydrated. This is called hyperemesis gravidarum and occurs in less than 2% of pregnant women (2 in every 100 pregnant women). Read more about hyperemesis gravidarum.
When to see a doctor for morning sickness
If you are vomiting and can’t keep any food or drink down, there is a chance that you could become dehydrated or malnourished. Contact your GP or midwife immediately if you:
- have very dark-coloured urine or do not pass urine for more than 8 hours
- are unable to keep food or fluids down for 24 hours
- feel severely weak, dizzy or faint when standing up
- have abdominal (tummy) pain
- have a high temperature (fever) of 38°C (100.4°F) or above
- vomit blood
- have pain when passing urine or any blood in your urine (this may be a urine infection).
What causes morning sickness?
The exact cause of morning sickness is unclear, but the symptoms are thought to be due to a combination of factors such as:
- high levels of pregnancy hormones, in particular, human chorionic gonadotrophin (hCG) and oestrogen
- fluctuations in blood pressure, particularly lowered blood pressure
- altered metabolism of carbohydrates
- the enormous physical and chemical changes that pregnancy triggers.
Morning sickness may be more likely to happen:
- when you have an empty stomach
- if you are stressed or anxious
- if you experience strong smells.
What increases my risk of morning sickness?
Morning sickness can occur in any pregnant woman, but some women are more prone to it. If you are pregnant you are more likely to develop morning sickness if:
- it is your first pregnancy
- you experienced nausea and vomiting in a previous pregnancy
- your unborn baby is a girl
- you have a family history of nausea in pregnancy
- you have a history of travel or motion sickness
- you get nausea when using contraceptives
- your BMI is 30 or higher
- you have a multiple pregnancy such as twins or triplets.
Self-care – what can you do to feel better?
Tips to manage morning sickness
|Fluids and hydration||
|Vitamin B6 (pyridoxine)||
|Exercise and fresh air||
|Rest and relaxation||
|Brushing your teeth||
|Acupressure bracelets or acupuncture||
- Effects of ginger for nausea and vomiting in early pregnancy: a meta-analysis. J Am Board Fam Med. 2014 Jan-Feb;27(1):115-22.1.