The Management of Nausea and Vomiting of Pregnancy and Hyperemesis Gravidarum

Question 1

How is NVP diagnosed?

Answer 1

• NVP should only be diagnosed when onset is in the first trimester of pregnancy and other causes of
  nausea and vomiting have been excluded.

Question 2

How is HG diagnosed?

Answer 2

• HG can be diagnosed when there is protracted NVP with the triad of more than 5% prepregnancy weight loss, dehydration and electrolyte imbalance.

Question 3

How can the severity of NVP be classified?

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.

Question 4

What initial clinical assessment and baseline investigations should be done before deciding
on treatment?

Answer 4

• Clinicians should be aware of the features in history, examination and investigation that allow NVP and HG to be assessed and diagnosed and for their severity to be monitored.

Question 5

What are the differential diagnoses?

Answer 5

• Other pathological causes should be excluded by clinical history, focused examination and investigations

Question 6

How should the woman be managed?

Answer 6

• Women with mild NVP should be managed in the community with antiemetics.
• Ambulatory daycare management should be used for suitable patients when community/primary care measures have failed and where the PUQE score is less than 13.
• Inpatient management should be considered if there is at least one of the following:
  ● 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 (such as urinary tract infection and inability to tolerate
  oral antibiotics).

Question 7

What is the safety and efficacy of pharmacological agents?

Antiemetics

Answer 7

• There are safety and efficacy data for first-line antiemetics such as antihistamines (H1 receptor
  antagonists) and phenothiazines and they should be prescribed when required for NVP and HG
• Combinations of different drugs should be used in women who do not respond to a single antiemetic.
• For women with persistent or severe HG, parenteral or rectal route may be necessary and more effective than an oral regimen.
• Women should be asked about previous adverse reactions to antiemetic therapies. Drug-induced
  extrapyramidal symptoms and oculogyric crises can occur with the use of phenothiazines and metoclopramide. If this occurs, there should be prompt cessation of the medications.
• Clinicians should use antiemetics with which they are familiar and should use drugs from different classes if the first drug is not effective.
• Metoclopramide is safe and effective, but because of the risk of extrapyramidal effects it should be used as second-line therapy.
• There is evidence that ondansetron is safe and effective, but because data are limited it should be used as second-line therapy.

Pyridoxine: is not recommended for NVP and HG.

Corticosteroids: should be reserved for cases where standard therapies have failed.

Diazepam:is not recommended for the management of NVP or HG.

Question 8

What is the best rehydration regimen for ambulatory daycare and inpatient management?

Answer 8

• Normal saline with additional potassium chloride in each bag, with administration guided by daily monitoring of electrolytes, is the most appropriate intravenous hydration.
• Dextrose infusions are not appropriate unless the serum sodium levels are normal and thiamine has been administered.

Question 9

Which complementary therapies could be helpful?

Answer 9

• Ginger: may be used by women wishing to avoid antiemetic therapies in mild to moderate NVP.
• Acustimulations – acupressure and acupuncture: Women may be reassured that acustimulations are safe in pregnancy. Acupressure may improve NVP.
• Hypnosis: Hypnotic therapies should not be recommended to manage NVP and HG.

Question 10

What complications or adverse effects can occur from NVP and HG and what are their preventive/ management strategies?

Answer 10

• Urea and serum electrolyte levels should be checked daily in women requiring intravenous fluids.
• Histamine H2 receptor antagonists or proton pump inhibitors may be used for women developing
  gastro-oesophageal reflux disease, oesophagitis or gastritis.
• 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 with HG should be offered thromboprophylaxis with low-molecular-weight heparin
  unless there are specific contraindications such as active bleeding. Thromboprophylaxis can be discontinued upon discharge.
• Women with previous or current NVP or HG should consider avoiding iron-containing preparations if these exacerbate the symptoms

Question 11

What is the role of the multidisciplinary team?

Answer 11

• In women with severe NVP or HG, input may be required from other professionals, such as midwives, nurses, dieticians, pharmacists, endocrinologists, nutritionists and gastroenterologists, and a mental health team, including a psychiatrist.

Question 12

When should enteral and parenteral nutrition be considered and what are the risks to the mother and
fetus?

Answer 12

• When all other medical therapies have failed, enteral or parenteral treatment should be considered with a multidisciplinary approach.

Question 13

When should termination of pregnancy be considered?

Answer 13

• All therapeutic measures should have been tried before offering termination of a wanted pregnancy.

Question 14

Discharge and follow-up

What discharge and follow-up arrangements should be implemented?

Answer 14

• Women with NVP and HG should have an
  individualised management plan in place when they are
  discharged from hospital.
• 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.

Question 15

What is the effect of NVP and HG in the postnatal period?

How should we advise about future pregnancies?

Answer 15

• Women with previous HG should be advised that there is a risk of recurrence in future pregnancies.
• Early use of lifestyle/dietary modifications and antiemetics that were found to be useful in the index
  pregnancy is advisable to reduce the risk of NVP and HG in the current pregnancy.

Question 16

What is the effect of NVP and HG on quality of life?

Answer 16

• A woman’s quality of life can be adversely affected by NVP and HG and practitioners should address severity of a woman’s symptoms in relation to her quality of life and social situation.
• Practitioners should assess a woman’s mental health status during the pregnancy and postnatally and refer for psychological support if necessary.
• Women should be referred to sources of psychosocial support.
• Practitioners should validate the woman’s physical symptoms and psychological distress.
• Women should be advised to rest as required to alleviate symptoms.

Question 17

History of NVP/HG

Answer 17

● Previous history of NVP/HG
● Quantify severity using PUQE score: nausea, vomiting, hypersalivation, spitting, loss of weight,
inability to tolerate food and fluids, effect on quality of life
● History to exclude other causes:
– abdominal pain
– urinary symptoms
– infection
– drug history
– chronic Helicobacter pylori infection

Question 18

Examination of NVP/HG

Answer 18

● Temperature
● Pulse
● Blood pressure
● Oxygen saturations
● Respiratory rate
● Abdominal examination
● Weight
● Signs of dehydration
● Signs of muscle wasting
● Other examination as guided by history

Question 19

Investigation of NVP/HG

Answer 19

● Urine dipstick:
– quantify ketonuria as 1+ ketones or more
● MSU
● Urea and electrolytes:
– hypokalaemia/hyperkalaemia
– hyponatraemia
– dehydration
– renal disease
● Full blood count:
– infection
– anaemia
– haematocrit
● Blood glucose monitoring:
– exclude diabetic ketoacidosis if diabetic
● Ultrasound scan:
– confirm viable intrauterine pregnancy
– exclude multiple pregnancy and trophoblastic disease
● In refractory cases or history of previous admissions, check:
– TFTs: hypothyroid/hyperthyroid
– LFTs: exclude other liver disease such as hepatitis or gallstones, monitor malnutrition
– calcium and phosphate
– amylase: exclude pancreatitis
– ABG: exclude metabolic disturbances to monitor severity

Question 20

Recommended antiemetic therapies and dosages

First line

Answer 20

● Cyclizine 50 mg PO, IM or IV 8 hourly
● Prochlorperazine 5–10 mg 6–8 hourly PO; 12.5 mg 8 hourly IM/IV; 25 mg PR daily
● Promethazine 12.5–25 mg 4–8 hourly PO, IM, IV or PR
● Chlorpromazine 10–25 mg 4–6 hourly PO, IV or IM; or 50–100 mg 6–8 hourly PR

Question 21

Recommended antiemetic therapies and dosages

Second line

Answer 21

● Metoclopramide 5–10 mg 8 hourly PO, IV or IM (maximum 5 days’ duration)
● Domperidone 10 mg 8 hourly PO; 30–60 mg 8 hourly PR
● Ondansetron 4–8 mg 6–8 hourly PO; 8 mg over 15 minutes 12 hourly IV

Question 22

Recommended antiemetic therapies and dosages

Third line

Answer 22

● Corticosteroids: hydrocortisone 100 mg twice daily IV and once clinical improvement occurs,
convert to prednisolone 40–50 mg daily PO, with the dose gradually tapered until the lowest
maintenance dose that controls the symptoms is reached