Affects approximately 75% of pregnant women.
Typically begins between the fourth and seventh week after the last menstrual period and resolves in the second trimester.
Aetiology remains unclear. There is some evidence that it is related to hormone levels of human chorionic gonadotrophin and oestrogen.
Hyperemesis gravidarum represents the most severe form of nausea and vomiting of pregnancy. While there is lack of consensus of definition, most agree that clinical features include persistent vomiting, volume depletion, ketosis, electrolyte disturbances, and weight loss.
Initial therapy should be conservative. This may include non-pharmacological treatments such as diet modification, emotional support, ginger, and acupressure.
Severe cases may require hospitalisation, intravenous fluids, anti-emetics, corticosteroids, and total parenteral nutrition.
Nausea and vomiting in pregnancy (NVP), commonly referred to as morning sickness, typically begins between the fourth and seventh week after the last menstrual period. It is characterised by nausea and vomiting that occur more frequently during the morning hours, and typically resolves in the second trimester. Hyperemesis gravidarum is the most severe form of NVP and is characterised by persistent vomiting, volume depletion, ketosis, electrolyte disturbances, and weight loss.
History and exam
Key diagnostic factors
- presence of risk factors
- first trimester of pregnancy
- weight loss of >5%
Other diagnostic factors
- absence of thyroid enlargement/nodules
- absence of central nervous system (CNS) signs
- dry mucous membranes
- postural dizziness
- ketotic breath
- family history of hyperemesis gravidarum
- previous history of NVP
- multiple gestation or increased placental mass
- gestational trophoblastic disease
- other causes of increased placental mass
- female fetus
- history of motion sickness
- history of migraine headache
1st investigations to order
- full blood count
- basic metabolic panel
- serum liver function tests
- serum urea and creatinine
- serum thyroid-stimulating hormone (TSH) and free thyroxine (T4)
- urine or serum ketones
- fetal ultrasound with nuchal translucency
- serum analytes
- Helicobacter pylori breath test
Investigations to consider
- urine culture
- serum amylase and lipase
- abdominal ultrasound
- renal ultrasound
- cranial CT or MRI
without volume depletion
without volume depletion but failed conservative management
with volume depletion
- Viral gastroenteritis
- Food poisoning
- Antenatal care
- Nausea and vomiting of pregnancy
Morning sickness: questions to ask your doctorMore Patient leaflets
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