|
|
|
|
|
|
|
|
Nausea and vomiting of pregnancy is the most common medical condition in pregnancy, affecting 50-90% of women. Persistent vomiting that leads to weight loss of greater than 5% of pre-pregnancy weight occurs in 1% and is referred to as hyperemesis gravidarum. This is associated with electrolyte abnormalities and dehydration.
|
Nausea and vomiting of pregnancy usually begins by 9-10 weeks of gestation, peaks at 11-13 weeks, and resolves in most cases by 12-14 weeks. In up to 10% of pregnancies, symptoms continue beyond 20 weeks. It is not confined to the morning.
Nausea and vomiting of pregnancy may be classified as mild, moderate or severe although this may not correlate with the distress caused. Nausea and vomiting of pregnancy can have a profound effect on a woman and her family’s health and quality of life, therefore early recognition and management is important.
|
Management
|
History and examination
|
The pathogenesis of nausea and vomiting of pregnancy and hyperemesis gravidarum is poorly understood and probably multifactorial. Idiopathic nausea and vomiting of pregnancy must be distinguished from that caused by gestational trophoblastic disease or multiple pregnancy and from other causes of nausea and vomiting such as gastrointestinal (peptic ulcer disease, GI obstruction, hepatitis, pancreatitis), genitourinary, central nervous system and toxic / metabolic problems (thyroid disease, adrenocortical insufficiency).
|
Investigations
|
Investigations include:
|
- urinalysis and MSU
- electrolytes (consider calcium), LFTs, plasma glucose, TSH once (beware interpretation of TFT in early pregnancy)
- early pregnancy ultrasound.
|
|
Dietary and lifestyle changes
|
Dietary and lifestyle changes should be encouraged. Women should be advised about appropriate foods and fluids to prevent dehydration and minimize aggravation of symptoms. Sleep requirement increases in early pregnancy and fatigue exacerbates nausea and vomiting of pregnancy. A liberal attitude towards leaves-of-absence from work should ultimately shorten the number of days lost from work.
|
Suggestions include:
|
- adequate oral fluid intake to prevent dehydration
- suitable multivitamin supplement if poor oral intake persists
- dietitian referral
- P6 (Nei Guan) acupressure – using wristbands e.g. SeaBand® (some evidence of efficacy).
|
 |
|
Drug guidelines
|
Mild or moderate symptoms
|
Previous severe nausea and vomiting of pregnancy or hyperemesis gravidarum (pre-emptive therapy recommended).
|
Progress through the following list of medicine options until symptoms controlled.
|
1. Pyridoxine (vitamin B6) 50mg orally up to QID or 200mg orally at night.
2. Add doxylamine (Restavit®) (H1 antagonist) 12.5mg orally nocté, increase to 25 mg nocté then add 12.5mg mané and afternoon as required.
3. Add another sedating antihistamine:
3.1 Promethazine (Phenergan®) 10 to 25mg orally three to four times a day OR
|
3.2 Dimenhydrinate (Dramamine®) 50 mg orally three to four times a day.
4. Add either of the following if not improving:
4.1 Metoclopramide (Maxolon®, Pramin®) 10mg orally three to four times a day OR
|
4.2 Prochlorperazine (Stemetil®) 5 to 10mg orally two to three times a day OR 25mg PR once to twice a day.
|
Consideration should be given to thiamine (Betamin®) supplementation to prevent the complication of Wernicke's encephalopathy. The suggested dose of thiamine is 100mg orally daily. Refer to the section below: Admission for intravenous fluids, for intravenous dose of thiamine and water soluble vitamins.
|
Severe, persistent or resistant nausea and vomiting
|
If severe, persistent or resistant nausea and vomiting is not relieved by the above measures consider:
|
5. Chlorpromazine (Largactil®) 10 to 25mg three to four times a day
6. Ondansetron (Zofran®) 4mg orally (tablet or wafer) two or three times a day. Must be approved by Head of Unit.
|
Women with nausea and vomiting or hyperemesis gravidarum may require treatment with parenteral anti-emetics and intravenous fluids. If planning to manage the woman as an outpatient, consider administering medications intramuscularly, otherwise administer intravenously.
|
Consider changing regime to any of the following:
|
1. Metoclopramide 10mg IV/IM every 8 hours
2. Prochlorperazine 12.5mg IM every 8 hours
3. Promethazine 12.5 to 25mg IM every 4 to 6 hours
4. Chlorpromazine 25 to 50mg IV/IM every 6 to 8 hours (maximum 75mg daily).
|
And if symptoms persist:
|
5. Ondansetron 4mg IV/IM every 8 to 12 hours
6. Prednisolone 50 mg orally daily for 3 days, then reduce to 25mg at 3 days then reduce by 5mg as tolerated until resolved (monitor blood glucose levels and consider prophylaxis with ranitidine 300 mg nocté a day to prevent GI upset).
|
Note: steroids may increase risk for oral clefts in the first 10 weeks of gestation.
|
|
|
Admission for intravenous fluids
|
Admit if dehydrated +/- ketotic for IV fluid resuscitation and electrolyte restoration with Sodium Chloride 0.9% – Hartmann’s has no advantage. Administer IV fluid volume as per clinical assessment. If hypokalaemic, the woman may require potassium (oral route preferred).
A water soluble vitamin solution (I.V. B-Dose® - contains thiamine 10mg) should be added to IV fluids - 1 ampoule may be administered in the ‘stat’ litre or the second (2 hourly) litre.
Thiamine 100mg IV daily for 2 to 3 days in women needing rehydration (should only be considered if there is an established risk of thiamine deficiency).
|
If adequate oral fluid intake cannot be maintained, IV hydration should be administered regularly (e.g. 2 to 3 times per week) in order to prevent dehydration. This can be performed in the Pregnancy Day Care Centre (PDCC) during the day. Some women who fit the Hospital in the Home (HITH) eligibility criteria may be able to receive their intravenous hydration at home. These women are visited twice weekly or as medically indicated and reviewed (medically) in Pregnancy Day Care Centre weekly.
|
Women may require antacids, H2 antagonists (ranitidine [Zantac®]) if gastritis develops.
|
Note: Cimetidine (Tagamet®) has more significant drug interaction, therefore ranitidine is preferred.
|
NOTE: Women who fail to respond to the above management should be assessed for enteral feeding (refer to Dietitian).
|
Appendices
|
Appendix 1
|
| Click on thumbnail to view full size image of algorithm:
| Nausea and Vomiting of Pregnancy: Medical Treatment Algorithm (pdf 29kb)
|
|
|
|
References
|
Refer to separate web page: References: Nausea and Vomiting of Pregnancy.
|
Published: 8/08/2008
|
|
|
Royal Women's Hospital Clinical Practice Guidelines (CPGs) are intended to provide guidance to health care professionals, based on a thorough evaluation of research evidence, on the practical assessment and management of specific clinical issues or situations. The guidelines allow some flexibility on the part of the health care professional based on the needs of the specific patient for whom they are caring.
|
Please remember to read our disclaimer.
|
