When does morning sickness start, peak, and end?

woman leaning over toilet feeling ill
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In general, morning sickness starts around week 5 and peaks by week 9 or 10, when levels of the pregnancy hormone human chorionic gonadotropin (hCG) are highest. For most women, morning sickness fades between 14 and 20 weeks.

When does morning sickness start?

Morning sickness – also called nausea and vomiting of pregnancy – affects different expecting moms at different times (and some not at all). But it usually starts around week 5 or 6 of pregnancy. For some women, that telltale queasy feeling is one of the first giveaways that they're pregnant.

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Unfortunately, morning sickness is very common. In fact, around 70 percent of pregnant women experience morning sickness in early pregnancy. In addition to nausea and vomiting, other symptoms of morning sickness include retching (dry heaving) and excessive salivation.

"Morning sickness" is a misleading term because the condition often starts in the morning and lasts all day. Some women feel better as the day wears on, but others find their symptoms get worse in the evening.

This unpleasant part of pregnancy is thought to be linked to the pregnancy hormone human chorionic gonadotropin (hCG) and estrogen. Both hormones rise rapidly in early pregnancy, and women with higher hCG levels (like moms of multiples) often have more severe morning sickness.

For some expecting moms dealing with morning sickness, it's reassuring to keep in mind that in this case, feeling crappy means that your body is doing what it's supposed to – producing hormones that support your baby's development. But plenty of women with healthy pregnancies never have morning sickness, so if you don't experience it, don't be alarmed.

Morning sickness usually isn't harmful to your health or to your growing baby, but it makes it hard to get through the day. A "mild" case can mean feeling nauseated for a short time every day and vomiting once or twice. Many women describe it as feeling "blech" all the time. Many also have specific and significant food aversions. In more serious cases, nausea lasts for several hours and vomiting happens frequently.

And in the worst cases, some women experience hyperemesis gravidarum (HG), a severe form of morning sickness that can result in weight loss, dehydration, and other complications. Women with HG throw up so often that they can't keep down enough food and fluid, and may need to be treated in the hospital with IV fluids, vitamins, and medication. (If you aren't able to keep liquids down for more than 12 hours, or solid foods down for 24 hours, call your healthcare provider.)

Because morning sickness is common in pregnancy, some providers may minimize it. And some expecting moms are reluctant to seek help, in part because they're worried about taking medications that could affect their baby. But there are safe ways to get relief from morning sickness, including changes to your diet and lifestyle, natural remedies, and medication prescribed by your provider. And many experts say that getting early help for morning sickness is important to prevent it from getting more severe. So be sure to talk to your provider if you're suffering.

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When does morning sickness peak?

It varies from woman to woman, but symptoms tend to be the worst at around 9 or 10 weeks, when levels of hCG are at their highest. At 11 weeks, hCG levels start to fall, and by 15 weeks they've dropped about 50 percent from their peak.

Scientists believe that morning sickness may be the body's way of protecting your baby in early pregnancy from toxins and potentially dangerous foods. This theory makes sense because the first trimester – when most women have the strongest morning sickness – is the crucial period of development when all of your baby's organs and physical structures form.

How long does morning sickness last?

Most women get relief from morning sickness by the second trimester, between 14 and 20 weeks. But some women with morning sickness continue to have symptoms beyond that, and a few women will experience it throughout their entire pregnancy.

If your morning sickness lasts beyond 20 weeks of pregnancy, occurs for the first time after 9 weeks of pregnancy, or lessens and then returns, play it safe and let your healthcare provider know. Persistent nausea and vomiting can sometimes indicate another medical problem – or just make you miserable – so it's important to be seen and possibly treated.

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BabyCenter's editorial team is committed to providing the most helpful and trustworthy pregnancy and parenting information in the world. When creating and updating content, we rely on credible sources: respected health organizations, professional groups of doctors and other experts, and published studies in peer-reviewed journals. We believe you should always know the source of the information you're seeing. Learn more about our editorial and medical review policies.

ACOG. 2021. Morning sickness: Nausea and vomiting of pregnancy. American College of Obstetricians and Gynecologists. a new window [Accessed August 2021]

Cleveland Clinic. 2021. Morning sickness (Nausea and vomitting of pregnancy). Cleveland Clinic a new window [Accessed August 2021] 

Marcella Gates

Marcella Gates is Director of Content Operations at BabyCenter, the world's number one digital parenting resource, and is an expert on pregnancy and parenting. As a mom of three, she loves that her professional life is focused on supporting and empowering parents and expecting parents. Gates lives in the San Francisco Bay Area with her family.