tay.generalcomments@nhs.scot

Nausea and Vomiting in Early Pregnancy

Summary

  • Nausea and vomiting in pregnancy (NVP) is common affecting up to 80% of pregnancies to some extent.
  • Hyperemesis gravidarum (HG) is less common and diagnosed in the presence of severe protracted vomiting, weight loss of >5% of pre-pregnancy weight, electrolyte imbalance and dehydration.
  • Early management in primary care may potentially avoid hospital admissions and significantly improve quality of life.
  • It most commonly presents between 4-7 weeks of gestation, peaking at 9 weeks with the majority resolving by 20 weeks.
  • First presentation >10+6 weeks is uncommon and other causes should be considered.

Primary care management 

  • The flowchart summarises suggested initial management in primary care and when to refer to secondary care.
  • In women with co-morbidities such as diabetes, a lower threshold for referring to secondary care should be considered.
  • PUQE score can help with objective assessment of symptoms and guide whether secondary care referral is needed.
  • The presence of urinary ketones does not correlate with symptom severity but can be used to determine if intravenous hydration is needed.
  • The potential severe psychological impact should always be considered and discussion with secondary care initiated in those voices concerns regarding deterioration in mental health, suicidal ideation or thoughts of ending a wanted pregnancy.
  • Anti-emetics should be provided on an acute prescription to ensure regular medication review.
  • Anti-emetics may be gradually reduced as symptoms improve and as tolerated with the expectation that the majority will be able to stop medications by 20 weeks.
  • NVP/HG tends to recur in subsequent pregnancies therefore patients may express a preference for medication choice based on previous experience and this should be supported.
  • Pre-emptive antiemetics may help
  • Some may require multiple anti-emetics to achieve symptom control.
  • There is a potential association between ondansetron use and an increased risk of cleft lip/palate; this should only be commenced in secondary care or following discussion with obstetrics or gynaecology on call registrar.
  • Patient information leaflets on safety of use can be accessed from 'bumps' - best use of medicine in pregnancy (medicinesinpregnancy.org) to reassure and inform. 
  • All women should be advised of support available through Pregnancy Sickness Support, see Get support (pregnancysicknesssupport.org.uk)

Recommended anti-emetics (use one or more 1st line in preference to second line):
  • 1st line
    • Cyclizine 50 mg PO or IM 8 hourly
    • Prochlorperazine 5-10 mg 6-8 hourly PO; or 12.5 mg 8 hourly IM; or 25 mg PR daily
    • Promethazine 12.5-25 mg 4-8 hourly PO, IM or PR
    • Chlorpromazine 10-25 mg 4-6 hourly PO or IM; or 50-100 mg 6-8 hourly PR
  • 2nd line
    • Metoclopramide 5-10 mg 8 hourly PO or IM
    • Domperidone 10 mg 8 hourly PO; or 30-60 mg 8 hourly PR
    • Ondansetron 4-8 mg 6-8 hourly PO

Who to refer

As per flowchart. 

How to refer

  • The Early Pregnancy Assessment Clinic does not manage patients with NVP or HG. All cases requiring secondary care input should be discussed with the on-call gynaecology registrar (Bleep 5610) less than 14 weeks and the on-call obstetric registrar (Bleep 5400) after 14 weeks.
  • Those seen for ambulatory or inpatient management in current pregnancy can self-refer back to Ward 36(<14 weeks) and maternity triage (>14 weeks) as needed throughout pregnancy if symptoms worsen or recur.