What are the key diagnostic criteria for hyperemesis gravidarum in pregnant patients presenting with severe nausea and vomiting?

Key diagnostic criteria for hyperemesis gravidarum (HG) in pregnant patients presenting with severe nausea and vomiting include:

• Severe and persistent nausea and vomiting that is not controlled by primary care or outpatient management, often extending beyond the first trimester.
• Inability to tolerate oral intake, including oral antiemetics and fluids.
• Clinical dehydration evidenced by signs such as dry mucous membranes or reduced urine output.
• Weight loss greater than 5% of pre-pregnancy body weight.
• PUQE (Pregnancy-Unique Quantification of Emesis) score greater than 13, indicating severe symptoms.
• Presence of complications or co-morbidities that worsen the clinical picture or prevent oral medication use.
• Need for inpatient care due to severity, including intravenous fluid therapy, electrolyte replacement, and possibly enteral or parenteral feeding.

These criteria are used to differentiate HG from common nausea and vomiting of pregnancy and to guide the need for escalation of care, including hospital admission and multidisciplinary management.

References: These criteria are based on the NICE guideline on Antenatal care and the Royal College of Obstetricians and Gynaecologists (RCOG) guideline on the management of nausea and vomiting of pregnancy and hyperemesis gravidarum ¹.