Hyperemesis Gravidarum

Kiung Hsia Ling 10/06/09

Nausea & vomiting: common (70-85%) Severe & intractable form of nausea &

vomiting fluid, electrolyte & acid base imbalance, nutritional deficiency & weight loss Peak incidence: 8-12 weeks of pregnancy Frequency: 0.5-2% of pregnancies Age: <30 years more likely to experience hyperemesis

Etiology is unknown ? Elevated human chorionic gonadotropin

(HCG) ? Elevated estradiol Has not been demonstrated conclusively

Physiologic effects  Weight loss, dehydration, deteriorating nutritional state

and often acid base & electrolyte alterations  Low birth weight infants  Spontaneous abortion, poor neurological development & preterm delivery  Mild to moderate ketonuria  Thiamine deficiency: increased demand for glucose metabolism, coupled with the inability to tolerate adequate food and vitamin/mineral supplements  Wernicke’s encephalopathy  Mild increase in liver enzymes (up to 4×)

Minimize discomfort & symptoms Prevent/minimize dehydration & electrolyte

imbalance Prevent/minimize ketonuria Achieve adequate oral fluid intake: 3035ml/kg/day Prevent unnecessary hospitalization

An obviously dehydrated woman, with

ketonuria > 2++ requires admission for IV rehydration and antiemetic therapy For severe, prolonged hyperemesis: IV thiamine 100mg/day Extreme case: may require nasogastric or parenteral nutrition Drink enough fluids to avoid dehydration, which exacerbates nausea

 Drink small amounts often  Sometimes other fluids are managed better than water –

flat lemonade, sports drinks, fruit juice, clear soup  Small amounts of food more often, rather than large meals  Avoid having empty stomach – nibble on light snacks between meals  Early morning nausea may be helped by eating a dry biscuit before getting out of bed  Salty foods may help – try potato crisps or salty biscuits  Avoid fatty, rich or spicy foods

Make the most of your best time of day – eat

well when you feel best or whenever you feel hungry If the small of hot food makes you feel ill – try having cold food instead. If possible avoid cooking & ask for help from friends & family Lie down when nauseated Avoid stress – living with the constant threat of nausea & vomiting is a stressor in itself

Pyridoxine (vit B6): effective in trials using doses of

30-75mg/day, up to 100mg/day can be given in divided doses Metoclopramide: most commonly prescribed, category B Antihistamine: promethazine, prochlorperazine, meclizine, resulting drowsiness (beneficial effect) Ondasetron: as last resort in view of the increased costs compared to other medications Recent evidence showed that intravenous methylprednisolone did not reduce duration of symptoms or readmission rates

Class

Drug

Dosage Ranges

Step 1 Supportive measures

Antihistamine

Diphenhydramine

25-50mg PO at bedtime B

Step 2 First-line Mx

Vitamine

Pyridoxine

10-25mg PO 3-4 ×

A

12.5-25mg PO q 4hrs

C

If no improvement, add promethazine Dopamine antagonist

Step 3a Second-line Mx

Step 3b Acute hydration, IV fluids

Preg. Risk Catergory

Promethazine

If no improvement, and patient is not dehydrated, add or switch to one of the following. If dehydrated, go to 3b Prokinetic agent

Metoclopramide

5-10mg TDS

B

Serotonin antagonists

Ondansetron

8mg BD

B

Dopamine antagonist

Prochlorperazine

5-10mg q 3-4 hours

C

Fluid replacement LR 1st liter, then D51/4 NS

Based on individual patient need

Vitamine Thiamine supplementation

100mg/day

 Ginger

 Trial: 66 women compared 1g ginger capsule with

placebo, reporting benefit both for nausea & vomiting with no adverse effects  Forms: tea, biscuits, candy  Acupressure

 Involves the stimulation of the P6 Neiguan point either 

  

manually or with elasticised bands The P6 point is on the inside of the wrist, about 2-3 finger breaths proximal to the wrist crease between the tendons about 1cm deep Manual pressure is applied to this point for 5 minutes every 4 hours Applied by wearing an elasticised band with a 1cm round plastic protruding button centred over the point Unfortunately, evidence is mixed

 Women unable to tolerate oral fluids require

admission to hospital  Women should be provided with dietary and lifestyle advice to prevent dehydration  Maintaining hydration is more important than nutrition in the short term  Severe or prolonged cases may require supplementation with thiamine, nasogastric or parenteral nutrition  Medications are probably underutilised. Of the various medications shown to be effective, pyridoxine has the least side effects. The most commonly prescribed drug is metoclopromide

 Parrish C. Management of Hyperemesis Gravidarum with

Enteral Nutrition. Practical Gastroenterology, June 2008  Moran P. et al. Management of Hyperemesis Gravidarum: the importance of weight loss as a criterion for steroid therapy. QJ Med 2002; 95:153-158  Sheehan P. Hyperemesis Gravidarum: Assessment and management. Australian Family Physician 2007; 36(9):698-781  CPM. Management of nausea and vomiting of pregnancy & Hyperemesis Gravidarum. 2008  Herbert W, et a;. Nause and vomiting of Pregnancy. Association of professors of Gynecology and Obstetrics, 2001 .