Antenatal Factors - Womb Invaders
- Infections transmitted transplacentally at any stage of gestation.
- 📌 TORCH: Toxoplasmosis, Other (Syphilis, VZV, Parvo B19), Rubella, Cytomegalovirus, Herpes simplex.
| Agent | Key Maternal Feature | Key Neonatal Sign |
|---|---|---|
| Toxoplasma | Asymptomatic; mono-like illness | Triad: Chorioretinitis, hydrocephalus, diffuse intracranial calcifications |
| Rubella | Fever, postauricular lymphadenopathy, maculopapular rash | Triad: Cataracts, PDA, sensorineural deafness; 'blueberry muffin' rash |
| CMV | Asymptomatic; mono-like illness | Periventricular calcifications, microcephaly, sensorineural hearing loss |
| HSV | Genital vesicular lesions | Skin-Eye-Mouth (SEM) disease, encephalitis, disseminated sepsis |
| Syphilis | Chancre, rash on palms/soles | Snuffles, saber shins, Hutchinson teeth, rhagades |
⭐ Exam Favourite: Cytomegalovirus (CMV) is the most common congenital infection worldwide.
Intrapartum Factors - Birth Canal Gauntlet
- Primary Threat: Ascending infection from maternal genital tract post-rupture of membranes.
- Key Pathogens: Group B Streptococcus (GBS), E. coli, Listeria monocytogenes.
- Major Risk Factors:
- Prolonged Rupture of Membranes (PROM): > 18 hours
- Maternal intrapartum fever (Chorioamnionitis): Temp ≥ 38°C
- Preterm delivery: < 37 weeks
- Maternal GBS colonization, especially with heavy rectovaginal load.
⭐ Adequate intrapartum antibiotic prophylaxis (IAP) for GBS is defined as receiving IV Penicillin G or Ampicillin for at least 4 hours before delivery.
Postnatal & Systemic Factors - Beyond Delivery
- Postnatal Exposure & Environment
- Nosocomial Infections (NICU): Risk ↑ with invasive lines, ventilation, and prolonged stay. Common pathogens: Staphylococcus aureus, Klebsiella, Pseudomonas, Candida.
- Community/Home: Poor hand hygiene, overcrowding, contaminated water/formula.
- Maternal Systemic Illness
- Diabetes Mellitus: Poor glycemic control impairs neonatal neutrophil function, increasing susceptibility.
- Immunodeficiency: Conditions like HIV or use of immunosuppressive drugs.
- Feeding Method
- Formula Feeding: Lacks protective antibodies; risk of contamination.
- Breastfeeding: Confers passive immunity.
⭐ Breast milk is rich in secretory IgA, lactoferrin, and lysozymes, which provide crucial protection against gut and respiratory pathogens.
High-Yield Points - ⚡ Biggest Takeaways
- Group B Streptococcus (GBS) is the leading cause of early-onset neonatal sepsis.
- Intrapartum antibiotic prophylaxis (IAP), typically with IV Penicillin G, is critical for GBS-positive mothers.
- Prolonged Rupture of Membranes (PROM >18 hours) significantly elevates sepsis risk.
- Maternal intrapartum fever is a cardinal sign of chorioamnionitis.
- Preterm birth (<37 weeks) is the single most significant risk factor for neonatal infection.
- Untreated maternal UTIs or other infections are also key risk factors.
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