Morning sickness

Morning sickness, also called nausea and vomiting of pregnancy (NVP), is a symptom of pregnancy that involves nausea or vomiting.^[1] Despite the name, nausea or vomiting can occur at any time during the day.^[2] Typically the symptoms occur between the 4th and 16th week of pregnancy.^[2] About 10% of women still have symptoms after the 20th week of pregnancy.^[2] A severe form of the condition is known as hyperemesis gravidarum and results in weight loss.^[1][6]

The cause of morning sickness is unknown but may relate to changing levels of the hormone human chorionic gonadotropin.^[2] Some have proposed that morning sickness may be useful from an evolutionary point of view.^[1] Diagnosis should only occur after other possible causes have been ruled out.^[3] Abdominal pain, fever, or headaches are typically not present in morning sickness.^[1]

Taking prenatal vitamins before pregnancy may decrease the risk.^[3] Specific treatment other than a bland diet may not be required for mild cases.^[2][6][3] If treatment is used the combination of doxylamine and pyridoxine is recommended initially.^[3][4] There is limited evidence that ginger may be useful.^[3][7] For severe cases that have not improved with other measures methylprednisolone may be tried.^[3] Tube feeding may be required in women who are losing weight.^[3]

Morning sickness affects about 70–80% of all pregnant women to some extent.^[4][5] About 60% of women experience vomiting.^[2] Hyperemesis gravidarum occurs in about 1.6% of pregnancies.^[1] Morning sickness can negatively affect quality of life, result in decreased ability to work while pregnant, and result in health-care expenses.^[3] Generally, mild to moderate cases have no effect on the fetus, and most severe cases also have normal outcomes.^[1] Some women choose to have an abortion due to the severity of symptoms.^[1] Complications such as Wernicke encephalopathy or esophageal rupture may occur, but very rarely.^[1]