When Does Morning Sickness Start and End? Week by Week

When does morning sickness start is one of the first questions after a positive test. The second is when it ends. For most people nausea begins between weeks 4 and 6, peaks around week 9, and eases somewhere between weeks 14 and 22, and this guide from Materna Health walks through each stage.

The short answer

• It starts between weeks 4 and 6 for most people, counted from the first day of the last period. ACOG notes that it nearly always begins before week 9.
• It peaks around week 9.
• It ends by week 14 for about half of people, and by week 22 for nine in ten.
• It lasts all day for most. True morning-only nausea is rare.

When does morning sickness start?

Pregnancy weeks are counted from the first day of your last period, so week 4 is roughly the week of the missed period. In a diary study of 363 pregnancies, the average first day of nausea was day 39, which falls in the middle of week 5.

Newer research timed the start from ovulation, which is more precise than period dates. In that study, pregnancy hormone began rising 8 to 10 days after ovulation, and two thirds of women felt their first symptoms 11 to 20 days after ovulation. For many people that puts the first queasy days right around the missed period.

This matches what we hear in the office. Once hCG starts to climb, nausea with or without vomiting is one of the most common first signs patients describe, along with breast tenderness, fatigue, and more trips to the bathroom. Our posts on the signs of implantation and the early signs of pregnancy before a positive test cover that first stretch in detail.

If you feel sick and the home test is still unclear, a blood hCG test can confirm a pregnancy days earlier than a urine test.

Week by week: start, peak, and end

• Weeks 3 to 4. Implantation happens and hCG begins to rise. A few people already notice a stronger sense of smell or an unsettled stomach.
• Weeks 5 to 6. The typical start. Nausea arrives in waves, often with food aversions and a gag reflex that is suddenly easy to trigger.
• Weeks 7 to 10. The climb and the peak. Diary studies put the worst symptoms in week 9.
• Weeks 11 to 14. About half of people feel real relief in this window.
• Weeks 14 to 22. The other half improve gradually. In a prospective study of 160 women, only 50 percent had relief by week 14, and 90 percent had relief by week 22.
• After week 22. Roughly one in ten still has symptoms. At that point nausea needs an active treatment plan.

Notice where the peak lands. Most OB practices schedule the first prenatal visit at 8 to 10 weeks, so the hardest weeks of nausea often pass before anyone has examined you. That gap is the reason Materna Health exists.

Nauseated now and weeks away from your first appointment? Our team can see you the same day or the next day, assess how you are doing, and start treatment in one visit. Book a morning sickness visit.

Why it is rarely just the morning

The name sets the wrong expectation. In the same study of 160 women, 1.8 percent had nausea limited to the morning, and 80 percent had nausea that lasted all day. The researchers found it similar in character and intensity to the nausea of chemotherapy.

It also costs people real time. In the diary study, 35 percent of employed women missed work because of symptoms, for an average of 62 hours.

Some nausea never announces itself. It shows up as a quiet loss of appetite, smaller portions, and meals you forget to eat. If that sounds familiar, our post on losing weight in the second trimester explains how to spot it.

When the timing does not fit the pattern

• It starts for the first time after week 9. ACOG lists this as a sign that something else may be causing the nausea, such as a thyroid, gallbladder, or stomach problem. It calls for an exam and labs.
• It never starts. Between 20 and 26 percent of people in these studies had no nausea at all. A pregnancy without nausea is a normal pregnancy.
• It stops suddenly. In the diary study, 40 percent of women said their symptoms ended abruptly, and the average end date was day 84, the close of week 12. If yours vanish much earlier and the worry is keeping you up, a pregnancy reassurance visit with an early pregnancy ultrasound gives you an answer the same day.
• It keeps getting worse. Nausea that escalates past the usual peak, with vomiting several times a day and weight loss, may be hyperemesis gravidarum. Our guide to the difference between morning sickness and hyperemesis gravidarum shows where the line sits, and the hyperemesis gravidarum symptoms page includes the HELP score we use to measure severity.

When to get help instead of waiting it out

Knowing that nausea usually ends by week 14 does not help much in week 7. ACOG notes that treating nausea and vomiting early may keep it from progressing to something more severe. Call or book a visit if any of these apply:

• You cannot keep fluids down for 24 hours
• You have lost weight since the positive test
• Your urine is dark, or you are urinating far less than usual
• You feel dizzy or faint when you stand
• Nausea is keeping you from working, parenting, or sleeping

Treatment works in steps. It usually begins with vitamin B6 and doxylamine, moves to prescription anti-nausea therapies when those fall short, and adds IV hydration when you are running dry. Our post on IV hydration for pregnancy nausea explains what that visit involves.

What this means at Materna

Materna Health works as a sidecar to your OB/GYN. You keep your doctor or midwife, and we cover the weeks in between, when nausea is at its worst and the next appointment is far away.

At a morning sickness and nausea visit in our West Village office, we score your symptoms, check your hydration, and start medication or IV fluids in the same chair. You can come back as often as you need, including several times a week during the peak. We send every note and result to your OB, so we work as their extra set of hands.

Most patients are seen the same day or the next day. You do not need a referral, and you do not need to be vomiting to qualify for care.

Morning sickness timing FAQs

What week is morning sickness the worst?

Week 9 for most people, with the hardest stretch running from week 7 to week 10. Symptoms that are still climbing after week 10 or 11 are a reason to be seen.

Can morning sickness start before a positive pregnancy test?

It can. hCG begins rising 8 to 10 days after ovulation, and some people feel queasy within days of that rise, before a home test turns positive. A blood test at our early pregnancy testing visit can settle the question sooner.

Is it a bad sign if morning sickness suddenly stops?

Usually no. Four in ten women in one large diary study said their nausea ended abruptly, and the average end date in that study was the close of week 12. If it disappears before week 9 along with bleeding or cramping, or the worry will not settle, a same-day ultrasound is the fastest way to know.

Can morning sickness last the whole pregnancy?

For a small group, yes. About one in ten people still have nausea after week 22, and people with hyperemesis gravidarum are more likely to have symptoms into the third trimester. Ongoing nausea is treatable at every stage of pregnancy.

Can morning sickness come back in the third trimester?

Some people feel nausea return late in pregnancy as the uterus presses on the stomach and reflux increases. New nausea in the third trimester, especially with headache, upper belly pain, or swelling, needs a call to your OB the same day.

Morning sickness follows a fairly predictable clock, and you do not have to watch that clock alone. If nausea is running your day, or the timing does not fit the pattern above, book a same-day or next-day visit and let us help you feel better this week.

Related reading from Materna

• morning sickness vs hyperemesis gravidarum
• hyperemesis gravidarum: the complete guide
• what to eat when you cannot eat
• signs of implantation