Nausea in pregnancy, commonly known as morning sickness, usually starts between the 4th and 9th week of pregnancy. It often begins around 6 weeks, typically about two weeks after a missed period. Most women experience nausea that peaks between weeks 8 to 10 or up to week 11, and it usually improves or goes away around the end of the first trimester, roughly by weeks 13 to 14. However, some women may experience nausea throughout the pregnancy or into the second trimester. Morning sickness can occur at any time of the day, not just in the morning, and symptoms can range from mild queasiness to severe vomiting. About 70% of pregnant women experience nausea, with vomiting affecting about 60%. In some cases, nausea and vomiting can become severe, a condition known as hyperemesis gravidarum, which may require medical treatment. In summary:

• Nausea usually starts between 4 and 9 weeks of pregnancy.
• It peaks around 8 to 10 weeks.
• Most women feel better by around 13 to 14 weeks.
• Some may experience symptoms longer, even throughout pregnancy.