Pregnancy Nausea: When It Starts and When It Ends

When does morning sickness usually start?

Nausea in pregnancy most commonly begins between weeks 5 and 6 — shortly after a missed period and around the time hCG levels are rising rapidly. Some people notice it as early as week 4; others not until week 8 or 9 1Ref 1Committee on Practice Bulletins—Obstetrics, American College of Obstetricians and Gynecologists (2018).ACOG Practice Bulletin No. 189: Nausea and Vomiting of Pregnancy.Prevalence (70–85%), timeline (weeks 5–6 onset, weeks 12–16 resolution), first-line treatment (B6 alone or with doxylamine), and hyperemesis gravidarum criteria and management.

The term "morning sickness" is a misnomer — nausea can occur at any time of day or night, and many people find it worst in the late afternoon or evening, or throughout the entire day. Nausea and vomiting affect approximately 70 to 80 percent of pregnant people, making it one of the most common early-pregnancy symptoms 1Ref 1Committee on Practice Bulletins—Obstetrics, American College of Obstetricians and Gynecologists (2018).ACOG Practice Bulletin No. 189: Nausea and Vomiting of Pregnancy.Prevalence (70–85%), timeline (weeks 5–6 onset, weeks 12–16 resolution), first-line treatment (B6 alone or with doxylamine), and hyperemesis gravidarum criteria and management2Ref 2Schrager NL, Adrien N, Werler MM, Parker SE, Van Bennekom C, Mitchell AA (2021).Trends in first-trimester nausea and vomiting of pregnancy and use of select treatments: Findings from the National Birth Defects Prevention Study.Approximately 70% of pregnant people experienced first-trimester nausea and vomiting in a large population-based study; prevalence estimates and treatment utilization patterns.

Rising hCG and estrogen levels play a role in triggering nausea, as does increased sensitivity of the digestive system.

When does morning sickness usually end?

For most people, nausea improves significantly between weeks 12 and 14 — roughly the end of the first trimester 1Ref 1Committee on Practice Bulletins—Obstetrics, American College of Obstetricians and Gynecologists (2018).ACOG Practice Bulletin No. 189: Nausea and Vomiting of Pregnancy.Prevalence (70–85%), timeline (weeks 5–6 onset, weeks 12–16 resolution), first-line treatment (B6 alone or with doxylamine), and hyperemesis gravidarum criteria and management. By week 16, the majority of people with pregnancy nausea feel substantially better.

However, there is meaningful variation: - About one in five people continues to have some nausea into the second trimester 1Ref 1Committee on Practice Bulletins—Obstetrics, American College of Obstetricians and Gynecologists (2018).ACOG Practice Bulletin No. 189: Nausea and Vomiting of Pregnancy.Prevalence (70–85%), timeline (weeks 5–6 onset, weeks 12–16 resolution), first-line treatment (B6 alone or with doxylamine), and hyperemesis gravidarum criteria and management - A smaller proportion experiences nausea throughout pregnancy - For a few people, nausea begins in the first trimester and peaks later, rather than resolving at 12 weeks

If nausea does not follow the expected arc, that alone is not a cause for alarm — but it is worth mentioning to your ob-gyn to rule out other causes and discuss symptom management.

What triggers nausea in pregnancy?

Common triggers vary by person but often include:

• Strong smells (cooking odors, perfume, coffee)
• Fatty, spicy, or rich foods
• Having an empty stomach — a drop in blood sugar can worsen nausea
• Motion
• Fatigue — nausea is often worse when tired
• Heat

Identifying personal triggers and adjusting around them is one of the most practical management steps.

What helps with morning sickness?

ACOG's Practice Bulletin on Nausea and Vomiting of Pregnancy recommends a stepwise approach 1Ref 1Committee on Practice Bulletins—Obstetrics, American College of Obstetricians and Gynecologists (2018).ACOG Practice Bulletin No. 189: Nausea and Vomiting of Pregnancy.Prevalence (70–85%), timeline (weeks 5–6 onset, weeks 12–16 resolution), first-line treatment (B6 alone or with doxylamine), and hyperemesis gravidarum criteria and management:

Eating patterns - Small, frequent meals throughout the day rather than three large ones - Eating before getting out of bed — keeping plain crackers on a bedside table and eating a few before rising - Choosing bland, lower-fat foods — plain starches tend to be better tolerated - Staying hydrated with small sips of water, ginger ale, or electrolyte drinks

Vitamin B6 (pyridoxine) - A standard first recommendation from ob-gyns; treatment with B6 alone or B6 plus doxylamine in combination is safe and effective and should be considered first-line pharmacotherapy 1Ref 1Committee on Practice Bulletins—Obstetrics, American College of Obstetricians and Gynecologists (2018).ACOG Practice Bulletin No. 189: Nausea and Vomiting of Pregnancy.Prevalence (70–85%), timeline (weeks 5–6 onset, weeks 12–16 resolution), first-line treatment (B6 alone or with doxylamine), and hyperemesis gravidarum criteria and management

Ginger - Ginger in various forms (ginger tea, ginger chews, ginger capsules) has modest evidence supporting its effectiveness for pregnancy nausea and is generally considered safe

Acupressure wristbands - Some people find relief from pressure point bands (P6/Neiguan point); evidence is mixed but they are safe to try

For more significant nausea, your ob-gyn may recommend prescription medications that are studied and considered safe in pregnancy.

What is hyperemesis gravidarum?

Hyperemesis gravidarum (HG) is a severe form of pregnancy nausea and vomiting that goes well beyond typical morning sickness. It occurs in approximately 0.5 to 2 percent of pregnancies and is characterized by 1Ref 1Committee on Practice Bulletins—Obstetrics, American College of Obstetricians and Gynecologists (2018).ACOG Practice Bulletin No. 189: Nausea and Vomiting of Pregnancy.Prevalence (70–85%), timeline (weeks 5–6 onset, weeks 12–16 resolution), first-line treatment (B6 alone or with doxylamine), and hyperemesis gravidarum criteria and management2Ref 2Schrager NL, Adrien N, Werler MM, Parker SE, Van Bennekom C, Mitchell AA (2021).Trends in first-trimester nausea and vomiting of pregnancy and use of select treatments: Findings from the National Birth Defects Prevention Study.Approximately 70% of pregnant people experienced first-trimester nausea and vomiting in a large population-based study; prevalence estimates and treatment utilization patterns:

• Vomiting multiple times per day that does not respond to standard measures
• Inability to keep any food or fluids down
• Significant weight loss (typically more than 5% of pre-pregnancy body weight)
• Dehydration — dark urine, dizziness, dry mouth
• Electrolyte imbalances

HG can begin in the first trimester and in severe cases continues through pregnancy. It is a medical condition — not something that can be managed by willpower — and may require IV hydration, medication, and sometimes hospitalization 1Ref 1Committee on Practice Bulletins—Obstetrics, American College of Obstetricians and Gynecologists (2018).ACOG Practice Bulletin No. 189: Nausea and Vomiting of Pregnancy.Prevalence (70–85%), timeline (weeks 5–6 onset, weeks 12–16 resolution), first-line treatment (B6 alone or with doxylamine), and hyperemesis gravidarum criteria and management.

If you are vomiting several times a day, cannot stay hydrated, or feel dizzy when standing, contact your ob-gyn or seek care promptly.