When does a woman start to experience morning sickness

Morning sickness can start very early for some women. About one in five women get nausea soon after they conceive, while about one in 30 start vomiting too.

But it's more usual to first experience nausea when you're five weeks or six weeks pregnant. If you don’t feel queasy in the early weeks, you may miss morning sickness altogether.

You may start to feel sick as soon as you wake up. But although it's called morning sickness, nausea can strike at any time of the day or night.

Certain smells may set off your nausea. Tiredness can also leave you feeling sick, so you may feel worse later in the day. Things that made you feel sick before you became pregnant may feel more nauseating now.

The sickness you feel is thought to be connected to the hormones human chorionic gonadotrophin (hCG) and oestrogen. These hormones are produced by your body in large quantities until the placenta has grown enough to take over nourishing your baby.

Pregnancy hormones are likely to be higher, and sickness worse as a result, if you're expecting a girl, or twins or triplets

If your morning sickness is severe, you may feel very sick and be vomiting often. The most severe form of morning sickness is hyperemesis gravidarum (HG), which means excessive vomiting during pregnancy.

If you can't eat or drink anything without being sick, and are vomiting many times a day, you may have HG. HG can cause dehydration and weight loss, so ask for help from your doctor as soon as possible.

Coping with morning sickness can be hard. It can make it difficult for you to work, do shopping, or look after your family. It can also be upsetting to be so unwell when you feel you should be happy.

Although morning sickness can make you feel miserable, it is a good sign. It means that the levels of hormones in your body are high, protecting your pregnancy. Rest assured that you should be through the worst by week 16.

Try not to worry if you don't feel sick at all – that's fine too, and it just means you've escaped an unpleasant pregnancy side-effect!

Take a look at these tips to help you keep nausea at bay.

Jenny Leach is an editor and writer specialising in evidence-based health content.

November 08, 2022 - 16:20 GMT When does morning sickness start? Get the lowdown on the common pregnancy symptom, including when it ends and morning sickness remedies

Morning sickness is one of the most common – and unpleasant – early pregnancy symptoms, and despite its name, it can happen at any time of day.

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An estimated 80 per cent of pregnant women experience nausea and vomiting in early pregnancy. While for some lucky women it can be short-lived, others may suffer for much longer, and one to three per cent of pregnant women develop hyperemesis gravidarum – excessive nausea and vomiting that often requires hospital treatment.

woman morning sickness

Morning sickness is one of the most common early pregnancy symptoms

From when morning sickness starts to the possible causes, we've got all the answers to your questions below…

Nausea and sickness can start at any time after conception, with some women affected as early as week four of pregnancy. However, most commonly it begins around week six and peaks between weeks eight to eleven.

Symptoms vary from woman to woman, and even pregnancy to pregnancy, and some women may not experience morning sickness at all.

MORE: 7 early pregnancy symptoms to look out for

What causes morning sickness?

Hormonal changes are believed to be the cause of nausea and vomiting during pregnancy, particularly human chorionic gonadotrophin (hCG) and oestrogen, which are produced by your body in large quantities until the placenta has grown enough to support and nourish your baby.

These hormonal changes may also heighten your senses, so you may become more sensitive to certain smells and tastes, which can also trigger nausea and sickness.

MORE: 7 best pregnancy pillows to combat back pain

pregnant woman holding bump

Hormonal changes are believed to cause morning sickness

Morning sickness has also been linked to blood sugar issues, which is why many women may feel most nauseous first thing in the morning before eating.

According to the NHS, you're more at risk of developing morning sickness if you're having twins or more, you had severe sickness in a previous pregnancy, you tend to get motion sickness, you have a history of migraine headaches and morning sickness in the family.

Other risk factors include a BMI of 30 or more, you're experiencing stress, it's your first pregnancy, and if you used to feel sick when taking contraceptives containing oestrogen.

Meanwhile, research suggests that women are more likely to experience morning sickness when expecting a girl, rather than a boy (Young, N.R., La Rosa, M., Mehr, S.A. et al., 2021), however, more research is required in this area and the severity of pregnancy symptoms are not considered indicative of a baby's gender.

When does morning sickness end?

Morning sickness often fades away at the end of the first trimester, and for the majority of women it typically clears up by weeks 16 to 20 of pregnancy.

If your symptoms are severe or you are dehydrated or losing weight, it's best to contact your GP or midwife so that you can be assessed and receive treatment.

References:

Young, N.R., La Rosa, M., Mehr, S.A. et al. Does greater morning sickness predict carrying a girl? Analysis of nausea and vomiting during pregnancy from retrospective report. Arch Gynecol Obstet 303, 1161–1166 (2021). https://doi.org/10.1007/s00404-020-05839-1

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How early can morning sickness start?

It usually starts at about 6 weeks of pregnancy and is at its worst at about 9 weeks. Most women feel better in their second trimester, but some have morning sickness throughout pregnancy. If you have morning sickness, tell your health care provider. Mild morning sickness doesn't harm you or your baby.

Can morning sickness start at 1 week?

Yes, you can feel pregnant before you miss your period. Some people say they've felt pregnancy symptoms within a week of conception (about one week before a missed period).