Hyperemesis Gravidarum

Last updated 25.08.13

Definition

-  Intractable vomiting during pregnancy leading to fluid, electrolyte and acid base imbalance, nutritional deficiency & weight loss >5% (pre-pregnancy weight)

 

Features

- Incidence 0.1-1% pregnancies

- Timing

-  Mean onset 5-6/40

-  Peaks 9/40

-  Improves by 16-20/40

-  60% patients asymptomatic by 6 weeks post onset

-  15-20% patients last to 3rd trimester

-  5% patients last to delivery

- 50-90% women have nausea & vomiting in pregnancy

-  Most common medical disorder in pregnancy

-  Nausea & vomiting in early pregnancy is ass w lower rates of miscarriage

- 60% pts develop secondary depression

- Multifactorial aetiology, possibly associated with Beta HCG & delayed gastric emptying

- Diagnosis of exclusion

 

Risk Factors

- Young maternal age

- Non-smoker

- First pregnancy

- Multiple gestations (twins..)

- Gestational trophoblastic diseae

 

DDx

-  Morning Sickness 60-70% patients

-  Multiple gestations (twins..)

-  Gestational trophoblastic diseae

-  Other causes of vomiting: bowel obstruction, PUD, UTI, thyroid disease..

 

Associated S/S

- Vomiting

-  Typically >x3/day

- Malaise

- Dizziness

- Weight loss >5% pre-pregnancy weight

 

Complications

- Wernickes (Thiamine deficiency)

- Mallory-Weis tears

- Central pontine myelinosis (Glucose given prior to Thiamine)

 

Ix

- Vitals

-  HR,BP: dehydration

-  Temp: Fever: infection

-  Dipstick + MSU for MCS

-  Exclude UTI

-  Ketonuria

-  SG: dehydration

-  FBE

-  U&E

-  Hypokalaemia

-  DDx Adrenal crisis

-  LFTs: hepatitis

-  Exepect mild ALP elevation in pregnancy

-  Vomiting itself may creat mild transaminitis

-  TSH: hyperthyroidsm in pregnancy

-  +/- thyroid antibodies

-  Decreased TSH +/- elevated T3/FT4 may be seen

-  Usually subclinical & transient & does not require Mx

-  +/- CMP: hypercalcaemia: hyperparathyroidism

-  BSL

-  Pelvic US

-  DDx trophoblastic disease, twins

-  +/- Abdominal US: if suspicious of other causes 

-  If severe consider

-  Infectious serology: CMV, EBV

-  +/- HCV, HBV

-  Autoimmune hepatitis screen: Anti-sm Ab, Anti-microsomal Ab, AFP

 

Mx

-  Diabetes Mellitis in Pregnancy

-  Home advice

-  Small frequent, dry meals

-  Adequate oral fluid intake

-  Multivitamin supplement if poor oral intake

-  +/- Dietician referral

-  Admission

-  If obvious dehydration or ketonuria 2+ or >

-  IV fluids

-  Hartmans or Normal Saline 2/24+/-

-  +/- Dextrose (Consider Thiamine first)

-  +/- potassium replacement (PO preferred route)

- If severe conisder NBM for 24hrs

-  Thiamine 100mg PO Daily

-  Anti-emetics

-  Mild to moderate S/S

-  Pyridoxine (Vit B6) 25-50mg PO up to QID or 200mg Nocte

-  +/- Doxylamine 12.5mg PO Nocte, increase to 25mg Nocte

-   +/- Add 12.5mg Mane & afternoon PRN

-  +/- Sedating antihistamine

-   Promethazine (Phenergan) 10-25mg PO TDS-QID

-   OR Dimenhydrinate (Dramamine) 50mg PO TDS-QID

-  +/- Metocloperamide 10mg PO TDS-QID

-   OR Prochlorperazine (Stematil) 5-10mg PO BD-TDS OR 25mg PR Daily-BD

-  Severe, persistant or resistant S/S

-  Ondansetron 4mg PO BD-TDS

-  If required change above regimen to IM or IV

-   Metocloperamide 10mg IV/IM 8/24

-   Prochlorperazine (Stematil) 12.5mg IM 8/24

-   Promethazine (Phenergan) 12.5-25mg IM 4-6/24

-   Ondansetron 4mg IV/IM 8-12/24 (w Consultant approval: B1 drug)

-  Recalcitrant S/S

-   Prednisolone 50mg PO Daily 3/7, then 25mg PO Daily 3/7

-  Reduce by 5mg as tolerated until S/S resolved

-  +/- PUD prophylaxis w Ranitidine 300mg Nocte

-  Use in first 10 weeks may increase risk of neonatal oral clefts

-  Ginger

-  Acupressure (Nei Guan PC9)

-  +/- Antacids if gastritis (blood stained, dyphagia..)

-  Ranitidine 150mg PO BD

-  Severe: NGT or parenteral feeds

 

 

References

 

RWH CPG: Nausea & Vomiting: Pregnancy, 30/07/2009

Peninsula Health CPG: Nausea & Vomiting in Pregnancy, October 2010

Upto Date: Clinical Features & Evaluation of Nausea & Vomiting in Pregnancy, 26/02/2012