Fetal Hydrops

Question 1

Diagnosis

Answer 1

• At least 2 of the following criteria on ultrasound
  o Subcutaneous oedema (>5mm fluid beneath skin)
  o Ascites
  o Pleural effusion
  o Pericardial effusion
• Often associated with polyhydramnios and thickened placenta

Question 2

Causes

Answer 2

-10% due to isoimmunisation
- 90% non immune

Question 3

Specific causes

Answer 3

Pneumonic: CAUSTIC:
1. Cardiac:
- Arrythmias: SVT/Heart Block (Anti Ro/LA pos)
- High output cardiac failure: Sacrococcygeal teratoma, placental tumour, haemangioma
- Structural abnormality: Hypoplastic left heart, cardiomyopathy, coarctation of the aorta
2. Anaemia
- Fetomaternal Haemorrhage
- Rhesus/Other isoimmunisation
- Parvovirus
-G6PD
- Alpah Thal (Barts Hydrops)
3. Unexplained
4. Structural
- Thoracic abnormality: CCAM, chylothorax, diaphragmatic hernia
- Skeletal dysplasia
5. Twins
- TTTS
6. Infection
- Parvovirus
- STORCH: Syphilis, Toxoplasma, Rubella, CMV, Herpes
- Other: Listeria, Coxsackie, Varicella
7. Chromosomal/Congenital
- Aneuploidy: XO, Trisomies 13, 18, 21, Noonan syndrome
- Congenital nephrotic syndrome, inherited disorders of metabolism

Question 4

Clinical Assessment

Answer 4

• History
  o Pregnancy complications ie bleeding
  o Aneuploidy testing
  o Blood group/Anti-D
  o Morphology result
  o Recent viral illness, possible exposures (ie childcare worker)
  o Ethnicity – ie risk of G6PD, alpha thalassaemia
• Examination
  o Presence of rash, fever
  o BMI, Urinalysiso Fundal height
  o Fetal Doppler auscultation +/- bedside ultrasound
• Investigations
  o Bloods
• FBE (microcytic anaemia suggestive of thalassaemia)
• Group and antibody screen
• Kleihauer
• G6PD/thalassaemia screening
• STORCH serology (especially Parvovirus)
• Anti-Ro, anti-La if suspected heart block
  o CTG
  o Ultrasound
• Tertiary scan for congenital anomalies and echocardiography
• Assessment of MCA PSV for fetal anaemia
• Growth/wellbeing/dopplers
  o Offer amniocentesis
• PCR for infections
• Karyotype

Question 5

Management

Answer 5

• Immediate referral to MFM unit
• Celestone if 24-34/40
• Termination can be offered if very pre-viable or severe abnormality identified
• Treat underlying cause
  o Anaemia
• Fetal blood sampling and intrauterine transfusion
  o Arrhythmia
• SVT – digoxin, sotalol, flecainide, amiodarone
• Bradycardia/heart block – salbutamol
  o Thoracic malformations
• Thoracentesis or shunt for pleural effusions
  o Syphilis
• Penicillin
• Observe for ‘mirror syndrome’
  o Development of oedema, hypertension, proteinuria in the mother
• Counselling
  o Prognosis depends on cause
  o If no cause identified: mortality 50%
  o If untreatable cause identified, termination should be offered
• Hydrops with structural cardiac anomaly has 100% mortality
  o Recurrence uncommon unless due to isoimmunisation or inherited disorder
• Delivery
  o If fetus stable, delivery at 37/40 in tertiary centre reasonable
  o CS for obstetric indications (ascitic tap prior to IOL if large AC)
  o Cord blood for serology, Coombe’s, FBE
  o Paediatricians in attendance (likely to need early intubation, diuretic, pleural tap, paracentesis)