It occurs in around 1% of pregnancies and is thought to be related to raised beta hCG levels. Hyperemesis gravidarum is most common between 8 and 12 weeks but may persist up to 20 weeks.
- Incidence: 13.00 cases per 100,000 person-years
- Peak incidence: 20-30 years
- multiple pregnancies
- trophoblastic disease
Smoking is associated with a decreased incidence of hyperemesis.
- Continued nausea and vomiting and is unable to keep down liquids or oral antiemetics
- Continued nausea and vomiting with ketonuria and/or weight loss (greater than 5% of body weight), despite treatment with oral antiemetics
- A confirmed or suspected comorbidity (for example she is unable to tolerate oral antibiotics for a urinary tract infection)
They also recommend having a lower threshold for admitting to hospital if the woman has a co-existing condition (for example diabetes) which may be adversely affected by nausea and vomiting.
- 5% pre-pregnancy weight loss
- electrolyte imbalance
Validated scoring systems such as the Pregnancy-Unique Quantification of Emesis (PUQE) score can be used to classify the severity of NVP.
- antihistamines should be used first-line (BNF suggests promethazine as first-line). Cyclizine is also recommended by Clinical Knowledge Summaries (CKS)
- ondansetron and metoclopramide may be used second-line
- ginger and P6 (wrist) acupressure: CKS suggest these can be tried but there is little evidence of benefit
- admission may be needed for IV hydration
- Wernicke's encephalopathy
- Mallory-Weiss tear
- central pontine myelinolysis
- acute tubular necrosis
- fetal: small for gestational age, pre-term birth