Hyperemesis Gravidarum: This is the most common cause of vomiting in pregnancy, especially during the first trimester. It is characterized by excessive vomiting, leading to dehydration and weight loss.

Gastroesophageal Reflux Disease (GERD): Pregnancy can exacerbate GERD symptoms due to increased pressure on the stomach and relaxation of the lower esophageal sphincter, leading to vomiting.
Food Poisoning: Similar to the general population, pregnant women can experience vomiting due to food poisoning, which can be caused by consuming contaminated food or drinks.
Gastroenteritis: Viral or bacterial infections can cause gastroenteritis, leading to vomiting, diarrhea, and abdominal cramps in pregnant women.

Preeclampsia: Although less common, preeclampsia can present with vomiting, especially if it progresses to severe preeclampsia or HELLP syndrome. Missing this diagnosis can be life-threatening for both the mother and the fetus.
Appendicitis: Appendicitis can cause vomiting and abdominal pain. In pregnancy, the appendix may be displaced upward, potentially altering the typical presentation and making diagnosis more challenging.
Urinary Tract Infection (UTI): A UTI can cause vomiting, especially if it progresses to pyelonephritis. UTIs are more common in pregnancy due to physiological changes.

Hydatidiform Mole: A rare condition where a non-viable fertilized egg implants in the uterus, leading to excessive vomiting, among other symptoms.
Multiple Pregnancy: Carrying twins or other multiples can increase the severity of morning sickness and vomiting due to higher levels of human chorionic gonadotropin (hCG).
Adrenal Insufficiency: Although rare, adrenal insufficiency can cause vomiting, and its diagnosis is critical due to the potential for severe consequences if left untreated.