Overview of nausea and vomiting during pregnancy
Nausea and vomiting are common symptoms in the early stages of pregnancy. In a minority of cases, nausea and vomiting may be sufficiently severe to require hospital admission for correction of dehydration and electrolyte imbalances (hyperemesis gravidarum).
Nausea and vomiting usually begin around week 6 and resolve around week 14 of gestation, so symptoms can generally be expected to improve around the end of the first trimester. A multiple pregnancy or molar pregnancy can cause severe vomiting in early pregnancy.
Persistent vomiting, or vomiting that starts after week 9 of gestation, should be investigated to exclude other causes such as infections (particularly pyelonephritis, see Acute pyelonephritis in adults) and rarer metabolic causes.
Severe vomiting that starts in late pregnancy may indicate pre-eclampsia or acute fatty liver of pregnancy.
Gastro-oesophageal reflux disease may contribute to nausea in pregnancy. Start treatment for reflux if present; see Gastro-oesophageal reflux during pregnancy.