Morning sickness: when does it start, when will it end and what helps?

Here's what you need to know about morning sickness in pregnancy: when it starts, when it ends, what's going on with your body, how it affects your baby, what can make it worse, and what you can do to make it better...

When does morning sickness start?

Morning sickness usually starts from around 6 weeks of pregnancy, which is approximately 2 weeks after your missed period. But it can start earlier or later.

You might notice that it comes on gradually or it might hit you full force all at once.

What are the symptoms of morning sickness? Will I definitely be sick?

The main symptom is nausea: a sensation of feeling sick or queasy. This feeling can be quite mild or really very strong indeed.

This can lead to burping and retching or dry-heaving and, for some women, full on, head-in-the-toilet-bowl vomiting.

Does every pregnant woman get morning sickness?

No. It's thought that 7 or 8 out of 10 pregnant women will have some level of nausea and or vomiting during pregnancy.¹ In one study of 363 pregnant women, approximately 80% were affected by morning sickness, with 28% of them having nausea only and about 50% having both nausea and vomiting².

About 1 to 3 out of every 100 pregnant women will have much more severe nausea and vomiting¹ – a condition called hyperemesis gravidarum that may require medical treatment.

But it's quite possible that you might not get morning sickness at all: 20% to 30% of pregnant women do not². Morning sickness is just one of many pregnancy symptoms and, if you don't get it, it doesn't follow that there is something wrong with your developing pregnancy.

What causes morning sickness?

We don't know the exact cause of pregnancy sickness but recent research studies have linked it to a hormone called GDF15, which all women (pregnant or not) make at low levels and which is also produced by the fetal part of the developing placenta and then sent into a pregnant woman's bloodstream.

A 2024 University of Cambridge study³ suggests that the degree of nausea and vomiting a pregnant woman experiences is directly linked both to how much GDF15 their developing foetus is producing and how sensitive the woman already is to GDF15 – women with normally lower levels of GDF15 seems to be more sensitive and more likely to get severe morning sickness and hyperemesis. It's hoped that there may be a way to prevent morning sickness in the future by gradually exposing women to GDF15 before they get pregnant, and so building up their resilience to it.

Other potential causes of morning sickness include high levels of hCG (human chorionic gonadotrophin), another hormone produced by the placenta during pregnancy.⁴ Levels of hCG rise rapidly in the earliest days of pregnancy, doubling every 2 days until they reach a peak at about week 12 to 14 and then slowly start to decline.

Morning sickness may also be triggered or affected by other hormonal changes in pregnancy, changes in your blood pressure and changes in your metabolism.

Are some people more likely to get morning sickness than others?

Not everyone will get morning sickness but there are some factors that increase your risk.⁴ These include:

• It's your first pregnancy
• You're pregnant with twins or more (much higher levels of hCG; see What causes morning sickness? above)
• You've had severe nausea and vomiting in a previous pregnancy
• You have blood relatives who were affected by morning sickness
• You have previously suffered with nausea when on the combined oral contraceptive pill
• You are susceptible to motion sickness and/or migraine
• You are obese
• You're stressed

Do you get morning sickness every day?

You might, but you might not. Some women feel sick all day, every day; others find that it comes and goes.

It's thought that morning sickness symptoms can be made worse by being tired, stressed or hungry – so that might explain why it can feels like morning sickness comes and goes.

How long in the day does it last? Is it normal to have it all day?

Unfortunately, the name 'morning' sickness, which implies that the nausea and vomiting only come in the morning, is very misleading.

Morning sickness can last all day or it can occur only at particular points in the day. Some pregnant women, for example, only ever experience morning sickness in the evening!

What week of pregnancy does morning sickness peak?

It varies from pregnant woman to pregnant woman but, generally, morning sickness tends to be at its worst at around 9 to 10 weeks of pregnancy – but the peak will be different for everyone.

When does morning sickness end?

For a small minority of pregnant women, morning sickness lasts for the whole pregnancy. Thankfully, for most of us, it tends to start improving at the end of the first trimester and tend to stop by about 16 to 20 weeks of pregnancy.

Does it stop suddenly or gradually?

Nausea is a bit like pain: we often only notice when it is there, as opposed to when it stops – which is our normal state. So you may not necessarily notice when your nausea stops. It can stop suddenly, or gradually and neither mean that there is a problem with the pregnancy.

Can morning sickness harm my baby?

Morning sickness is horribl, but it does not put your developing baby at increased risk, as long as you are able to keep hydrated. This means that you need to try to keep drinking, little and often.

Don’t worry if you cannot eat as healthily as you would like or are not managing to eat a lot: your baby will take all it needs from the stores in your body.

If I have bad morning sickness, does it mean I'm having a girl?

There are various old wives' tales around morning sickness, including that having it badly means it is a 'strong pregnancy' or you're having twins or a girl, but there is no evidence to back any of these tales up.

What helps reduce morning sickness symptoms?

There are some good tips that can help reduce your morning sickness symptoms. These include:

• Eat small meals regularly. Being hungry can make symptoms worse, so eat little and often.
• Eat before you get out of bed in the morning – again, to help if hunger is worsening your nausea.
• Choose simple foods that are high in carbs and low in fat, and which are easy to digest – such as rice, crackers or toast.
• Eat cold food – if the smell of cooking worsens your nausea.
• Keep up your fluid intake. Making your drinks very cold may help, and sip little and often instead of drinking a pint of water in one go.
• Try ginger in your food or drink.
• Acupressure might help. You could try some anti-nausea wrist bands or bracelets.
• Supplement with Vitamin B6. This might help with your nausea⁵, but not with vomiting. Side effects can include headaches, though. Do not take any over the counter medications or supplements without discussion with your pharmacist and/or antenatal team.
• Try to get enough rest. Fatigue and stress can make the symptoms worse.

What do I do if my morning sickness doesn't stop?

Unfortunately, some pregnant women will keep having nausea and vomiting throughout their pregnancy or may even notice that it starts in their last trimester. Follow the tips above and if you aren’t managing or are concerned, please speak to your antenatal team.

What do I do if my morning sickness is really bad? Should I see my doctor?

If you are really struggling with morning sickness, please see your doctor as there are medical treatments available.

Hyperemesis gravidarum is a condition with severe, intractable vomiting that may mean you need be be admitted to hospital for intravenous fluids and other medications. If you have any of the following symptoms, please seek urgent medical help:

• You haven't been able to keep any food or fluids down for 24 hours
• You haven't done a wee for more than 8 hours
• You feel very weak, dizzy or faint when you stand up
• You have abdominal pain
• You vomit blood
• You're losing weight

Pic: Getty Images

References:

<sup>1 Severe vomiting in pregnancy. NHS online
2. A prospective study of nausea and vomiting during pregnancy. Gadsby et al. Br J Gen Pract. 1993 Jun;43(371):245-8. Erratum in: Br J Gen Pract 1993 Aug;43(373):325. PMID: 8373648; PMCID: PMC1372422; Why seven in ten women experience pregnancy sickness. University of Cambridge, 13 December 2023
3. GDF15 linked to maternal risk of nausea and vomiting during pregnancy. Fejzo et al. Nature 625, 760–767 (2024). https://doi.org/10.1038/s41586-023-06921-9
4. Nausea and vomiting of pregnancy. Lee at al. Gastroenterol Clin North Am. 2011 Jun; 40(2): 309–vii.
5 Treating morning sickness with Unisom and Vitamin B6. Healthline.com</sup>

Read more:

• What does it mean if you don't get morning sickness?
• Is it safe to take paracetamol in pregnancy?
• How your breasts change in pregnancy, week by week