Nausea and vomiting in the early stages of pregnancy - Causes and Symptoms

Related articles: Nausea and vomiting in the early stages of pregnancy

Definition

Nausea and vomiting are frequent symptoms during pregnancy, especially during the 1st trimester; they can occur at any time of the day, regardless of meals. The pathophysiological mechanisms that determine its onset are not yet known, however the involvement of metabolic, hormonal, gastrointestinal and psychological factors has been hypothesized.

During the early stages of pregnancy, the most frequent causes of nausea and vomiting are morning sickness, hyperemesis and pregnancy and gastroenteritis.

The morning sickness induced by pregnancy mostly appears in the morning on an empty stomach and is characterized by mild and self-limiting symptoms. In hyperemesis gravidarum, instead, vomiting and nausea are so frequent and persistent as to determine an important dehydration, often associated with anomalies of the electrolyte, ketosis and weight loss. More rarely, a severe persistent vomiting, related to pregnancy, is caused by a hydatiform mole, that is a gestational trophoblastic disease that prevents the normal development of the embryo and causes an excessive enlargement of the uterus, with vaginal bleeding and pre-eclampsia.

Nausea and vomiting can also be induced by non-obstetric causes. Gastroenteritis and conditions that cause acute abdomen (eg appendicitis, cholecystitis, etc.) may occur during pregnancy, but are generally accompanied by other manifestations, such as diarrhea, constipation and abdominal pain. Similarly, headache, meningism or other symptoms suggest a neurological cause, such as migraine, cerebral hemorrhage and benign intracranial hypertension.

Other causes of vomiting and nausea in pregnancy include hepatitis, nephrolithiasis, gastroduodenal ulcer, hyperthyroidism, intestinal obstruction, diabetic ketoacidosis, gastroparesis, urinary tract infections and pyelonephritis. Certain drugs or vitamin preparations taken during pregnancy can also contribute to nausea (eg iron-containing compounds).