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Maternal factors and neonatal infection risk

Maternal factors and neonatal infection risk

Maternal factors and neonatal infection risk

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Antenatal Factors - Womb Invaders

  • Infections transmitted transplacentally at any stage of gestation.
  • 📌 TORCH: Toxoplasmosis, Other (Syphilis, VZV, Parvo B19), Rubella, Cytomegalovirus, Herpes simplex.
AgentKey Maternal FeatureKey Neonatal Sign
ToxoplasmaAsymptomatic; mono-like illnessTriad: Chorioretinitis, hydrocephalus, diffuse intracranial calcifications
RubellaFever, postauricular lymphadenopathy, maculopapular rashTriad: Cataracts, PDA, sensorineural deafness; 'blueberry muffin' rash
CMVAsymptomatic; mono-like illnessPeriventricular calcifications, microcephaly, sensorineural hearing loss
HSVGenital vesicular lesionsSkin-Eye-Mouth (SEM) disease, encephalitis, disseminated sepsis
SyphilisChancre, rash on palms/solesSnuffles, 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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