Hyperemesis Gravidarum

Question 1

When is nausea and vomiting of pregnancy (NVP) generally diagnosed, what causes it.

Answer 1

Should be diagnosed when onset is in the first trimester of pregnancy and other causes of nausea and vomiting have been excluded. It occurs in up to 80% of pregnant women and is one of the most common indications for hospital admission amongst pregnant women.
It is primarily associated with rising levels of b-hCG and conditions that cause this (GTD and multiple pregnancy.) It also tends to be worse in the first pregnancy and overweight or obese women.

Question 2

Definition of hyperemesis gravidarum

Answer 2

A severe form of NVP, which affects around 0.3-3.6% of pregnant women. It is excess vomiting and nausea leading to rejection of all food and drink. It is classified as ‘protracted’ NVP plus:
* More than 5% weight loss compared with before pregnancy
* Dehydration
* Electrolyte imbalance

Question 3

How can the severity of NVP be assessed

Answer 3

An ‘objective and validated index of nausea and vomiting’ such as the Pregnancy-Unique Quantification of Emesis (PUQE) score can be used to classify the severity of NVP- this gives a score out of 15:
* <7: Mild
* 7-12: Moderate
* >12: Severe

Question 4

Investigations for NVP

Answer 4

Question 5

When should ambulatory daycare management be considered

Answer 5

In suitable patients when community/primary care measures have failed and where the PUQE score is less than 13.
* Provide parenteral fluids, vitamins and antiemetics

Question 6

When should inpatient management of NVP be considered

Answer 6

• Continued nausea and vomiting and inability to keep down oral antiemetics
• Continued nausea and vomiting associated with ketonuria and/or weight loss (greater than 5% of body weight), despite oral antiemetics
• Confirmed or suspected comorbidity

Question 7

What risks are associated with the use of phenothiazides and metaclopromide

Answer 7

• Drug-induced extrapyramidal symptoms and oculogyric crises
  metoclopramide is a 2nd line agent owing to these risks. Ondansetron is also considered 2nd line due to the paucity of evidence surrounding its use

Question 8

Treatment of hyperemesis gravidarum

Answer 8

• First line agents include: Cyclizine, Promethazine, Chlorpromazine, Prochlorperazine
• For women with persistent or severe HG, the paraenteral or rectal route may be necessary and more effective than oral regimes
• Corticosteroids should be reserved for cases where standard therapies have failed
• When all other medical therapies have failed, enteral or parenteral treatment should be considered with a multidisciplinary approach.
• Women with severe NVP or HG who have continued symptoms into the late second or the third trimester should be offered serial scans to monitor fetal growth
• Women should be advised that there is a risk or recurrence in future pregnancies (may benefit from early use of lifestyle/ dietary modification)- varies from 15-81%

For REHYDRATION:
* Normal saline with additional potassium chloride in each bag, with administration guided by daily monitoring of electrolytes
* Dextrose is NOT appropriate unless serum sodium is normal and thiamine has been administered

Question 9

How should women with hyperemesis gravidarum be monitored

Answer 9

• Urea and serum electrolytes should be checked daily in women requiring IV fluids
• Thiamine supplementation (either oral or intravenous) should be given to all women admitted with prolonged vomiting, especially before administration of dextrose or parenteral nutrition
• Women admitted for HG should also be offered thromboprophylaxis with LMWH unless contraindicated
• Should consider avoiding iron-containing preparations since these can exacerbate symptoms