Neonatal Sepsis

Neonatal Sepsis: Pathogenesis and overview of clinical findings Maternal Risk Factors
Author: Nick Baldwin, Daria Mori Reviewers: Elizabeth de Klerk, Jody Platt, Mao Ding, Yan Yu Naminder Sandhu* *MD at time of publication
Neonate Risk Factors
Prolonged rupture of membranes
> 18 hours prior to delivery
bacteria in urine during pregnancy
Poor prenatal care (mechanism unclear; multifactorial)
Group B Strep vaginal colonization
Intra- amniotic infection
Prematurity (< 37 weeks) or low birth weight (< 2500 gm) Under- developed immune system Predisposed to infection Congenital anomaly that disrupts skin Birth asphyxia (lack of oxygen and blood flow to brain) Male gender (mechanism unclear) Invasive Procedures Direct introduction of bacteria to neonate’s blood ↑ likelihood of introducing bacteria to the fetus Vertical transmission of maternal bacteria from lower genital tract to uterus Contamination of amniotic fluid Fetal bacteremia (presence of bacteria in bloodstream Direct transmission of bacteria from maternal birth canal to fetal blood during delivery Disruption in neonatal host defenses Neonatal Sepsis An invasive infection, usually bacterial, occurring during the neonatal period (<4 weeks of age for term infants, or <4 weeks after the due date for preterm infants) Note: *APGAR = appearance, pulse, grimace, activity and respirations at 1-, 5-, and 10-min post birth Gastrointestinal Poor feeding Vomiting Diarrhea, constipation, or bloody stool Urological ↓ Urine output Note: See relevant slide(s) for mechanisms of how each sign and symptom comes about. CVS/RESP Apnea/tachypnea Labored breathing Pallor or cyanosis Brady-/tachycardia Hypotension Metabolic Jaundice Hypo- or hyper-glycemia Metabolic acidosis CNS Lethargy Irritability Focal neurological signs Seizure General Low APGAR* Temperature instability Bulging or sunken fontanels Rash Legend: Pathophysiology Mechanism Sign/Symptom/Lab Finding Complications Published June 3, 2013, updated June 7, 2023 on