Hyperemesis gravidarum

Whilst the majority of women experience nausea (previously termed 'morning sickness') during the early stages of pregnancy it can become problematic in a minority of cases. The Royal College of Obstetricians and Gynaecologists (RCOG) now use the term 'nausea and vomiting of pregnancy' (NVP) to describe troublesome symptoms, with hyperemesis gravidarum being the extreme form of this condition. (View all RCOG Green-Top Guidelines HERE.)

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.

Risk factors

• increased levels of beta-hCG
  • multiple pregnancies
  • trophoblastic disease
• nulliparity
• obesity
• family or personal history of NVP

Smoking is associated with a decreased incidence of hyperemesis.

Referral criteria for nausea and vomiting in pregnancy

NICE recommend considering admission in the following situations: #link9

• 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 admission to hospital if the woman has a co-existing condition (for example diabetes) that may be adversely affected by nausea and vomiting.

Hyperemesis gravidarum

The Royal College of Obstetricians and Gynaecologists (RCOG) recommend that the following triad is present before diagnosis of hyperemesis gravidarum:

1. 5% pre-pregnancy weight loss
2. dehydration