Chapter 36. Genetics

Cardiac

20%

Fetal arrhythmias (bradyarrhythmias and tachyarrhythmias)

Structural cardiac defects causing congestive failure

Extrinsic compression of heart causing low output states → leads to fetal tachyarrhythmia → high-output failure → hydrops

Myocarditis

Renal

5%

Nephrosis

Renal hypoplasia/aplasia

Renal vein thrombosis

Obstructive uropathies

Infection

8%

Toxoplasmosis

Herpes simplex virus

Syphilis

Adenovirus

Rubella

CMV

Hepatitis

Parvovirus

Pulmonary

5%

Congenital chylothorax

Pulmonary lymphangiectasia

Congenital diaphragmatic hernia

Cystic adenomatoid malformations

Other intrathoracic masses (eg, pulmonary sequestration) that cause compression of thoracic blood vessels → obstructive venous flow → hydrops

Placenta/cord

Rare

Chorangioma

Arteriovenous malformation

Significant cord compression

Umbilical vein thrombosis

True umbilical cord knot

Maternal conditions

5%

Diabetes mellitus

Severe preeclampsia/ eclampsia

Hyperthyroidism

Gastrointestinal

5%

In utero midgut volvulus

Bowel atresias

Chromosomal

10%

Turner syndrome

Aneuploidy

Trisomies 13, 18, 21

Noonan Syndrome

Miscellaneous

10%

Congenital myopathies

Inborn errors of metabolism

CNS malformations

Skeletal dysplasias

Abdominal neoplasms

Unknown

20%

Pulmonary

• Difficult intubation due to severe edema of head/neck/oropharynx. → Consider ENT or anesthesia support for intubation as needed.
• Varying degrees of pulmonary hypoplasia due to large pleural effusions or other extrinsic in utero compression of lungs → May need emergent thoracentesis in delivery area to alleviate lung compression from large effusions.
• Chest tube placement for rapidly reaccumulating pleural effusions.

Cardiovascular

• Hypotension should be treated with appropriate inotropic support.
• Remember that most hydropic infants are euvolemic intravascularly, often with depressed cardiac function → Avoid large fluid shifts.
• Pericardiocentesis may be necessary if cardiac tamponade from pericardial effusion is suspected → Should ideally be done under US guidance.
• Arterial access is helpful to follow invasive blood pressures.
• Echocardiogram should be obtained to evaluate for structural abnormalities as a cause of hydrops.

Fluids and electrolytes

• Infants are total body fluid overloaded but are usually euvolemic (intravascular status).
• Fluid intake should be based on a “dry” weight (ie, the 50th percentile for gestational age).
• Fluids should be restricted (40–60 mL/kg/day) to avoid further fluid overload and to allow diuresis.

• Vigilant attention to all ...