This is a new guideline from the RCOG on the management of nausea and vomiting in pregnancy. Most of this isn't going to change our practice, but if (like me) you get nervous about prescribing antiemetics in pregnancy, it gives good guidance. I'm just summarising things that were new to me, or that I felt were particularly important.
- Protracted nausea and vomiting in pregnancy (NVP) AND
- More than 5% pre-pregnancy weight loss AND
- Dehydration AND
- Electrolyte imbalance.
- Beware abdominal pain - this is not normally a feature in NVP or hyperemesis.
- Do a symptom score to judge severity, eg the PUQE score (Pregnancy Unique Quantification of Emesis).
- Dipstix for ketonuria (1+ or more counts)
- Send an MSU (this is to exclude UTI as a cause of the symptoms).
Who needs admission?
- Ongoing NVP and unable to keep down antiemetics.
- Ongoing NVP with ketonuria and / or weight loss of greater than 5%, despite oral antiemetics.
- Confirmed or suspected comorbidity (eg UTI)
What antiemetics should we use?
- Metoclopramide (second line because of the extrapyramidal side-effects).
- Domperidone (beware MHRA guidance on safe use).
- Ondansetron, 4 - 8mg 6 - 8 hrly PO (it is thought to be safe and effective, but data is limited, hence it is advised only for second line use. There are some studies suggesting concerns over safety, but no consistent data).
Combinations of different classes of drugs can be used if the above are not effective.
Parenteral or PR routes may be more effective.
What drugs are not recommended?
- Pyridoxine (there is a lack of consistent evidence that it is effective).
- Diazepam (1 small study showing a reduction in nausea, but not in vomiting)
- Corticosteroids (there is evidence of efficacy in patients with severe symptoms, so should only be used if other treatments have failed)
What complementary therapies can be advised?
- Ginger (there is evidence of efficacy, though it can sometimes cause maternal GI irritation and there is a potential interaction with b-blockers and benzodiazepines).
- Acustimulation (patients can be reassured that it is safe - there is some evidence that acupressure can help, eg wristbands, but there is no evidence that acupuncture helps).
- Hypnosis should not be used (there isn't sufficient evidence of efficacy).
Other management points
- H2 receptor antagonists and PPI can be used for GORD, oesophagitis or gastritis (the latter are safe and studies suggest that the former are safe, though more studies are needed).
- Iron supplements. Can exacerbate symptoms so may be worth avoiding in women with previous NVP or hyperemesis.
- Future pregnancy. Women should be advised to use early lifestyle, dietary or antiemetic measures to try to reduce the risk and severity of NVP in future pregnancies. There is some evidence that pre-emptive use of antiemetics can help.