Viral infections of the foetus and newborn.

1. Big picture

Viral infections of the fetus and newborn are important because they can cause:

maternal infection during pregnancy
→ placental transmission or perinatal exposure
→ fetal damage / congenital infection / neonatal infection
→ miscarriage, malformations, growth restriction, CNS damage, sepsis-like illness, death

For exams, focus on the classic congenital/perinatal viral infections:

---

2. Classification by timing of infection

The earlier in pregnancy infection occurs, the higher the risk of malformation. Later infection more often causes growth restriction, organ disease, or neonatal illness.

---

3. General clinical pattern of congenital viral infection

Think congenital infection if a newborn has:

• Intrauterine growth restriction
• Microcephaly
• Hydrocephalus or intracranial calcifications
• Seizures
• Chorioretinitis
• Cataract
• Sensorineural hearing loss
• Hepatosplenomegaly
• Jaundice
• Thrombocytopenia
• Petechiae or “blueberry muffin” rash
• Anemia

Mnemonic: “SMALL TORCH baby”

S — Small for gestational age M — Microcephaly A — Anemia L — Liver/spleen enlargement L — Low platelets T — Thrombocytopenic petechiae O — Ocular disease R — Rash C — CNS calcifications H — Hearing loss

---

4. Diagnostic approach: stepwise