Differential Diagnosis for Nausea and Vomiting in the Third Trimester of Pregnancy

Single Most Likely Diagnosis

• Hyperemesis gravidarum: Although more common in the first trimester, it can persist or recur in the third trimester. The condition is characterized by severe nausea and vomiting, often leading to dehydration and weight loss.

Other Likely Diagnoses

• Gastroesophageal reflux disease (GERD): The increased pressure from the growing uterus can cause stomach acid to flow back into the esophagus, leading to nausea and vomiting.
• Pregnancy-related gastrointestinal motility disorders: Hormonal changes can affect the motility of the gastrointestinal tract, leading to nausea and vomiting.
• Urinary tract infections: UTIs are common during pregnancy and can cause nausea and vomiting, especially if they progress to pyelonephritis.
• Food poisoning or viral gastroenteritis: These conditions can occur at any time during pregnancy and cause nausea and vomiting.

Do Not Miss Diagnoses

• Preeclampsia: A condition characterized by high blood pressure and often accompanied by protein in the urine. Nausea and vomiting can be symptoms, especially if the condition is severe.
• Placental abruption: A life-threatening condition where the placenta separates from the uterus, causing pain, bleeding, and potentially nausea and vomiting.
• Appendicitis: Although less common during pregnancy, appendicitis can occur and may present with nausea and vomiting, along with abdominal pain.
• Diabetic ketoacidosis: In women with pre-existing or gestational diabetes, high blood sugar levels can lead to diabetic ketoacidosis, which includes symptoms like nausea and vomiting.

Rare Diagnoses

• Acute pancreatitis: Inflammation of the pancreas, which can be caused by gallstones or other factors, leading to severe abdominal pain, nausea, and vomiting.
• Adrenal insufficiency: A rare condition where the adrenal glands do not produce enough hormones, potentially causing nausea and vomiting among other symptoms.
• Hyperthyroidism: An overactive thyroid gland can cause nausea and vomiting, among other symptoms like weight loss and palpitations.
• Hepatitis: Inflammation of the liver, which can be caused by viral infections or other factors, leading to nausea and vomiting, along with jaundice and abdominal pain.