What are the signs and symptoms of early-onset Group B Streptococcus (GBS) disease in a newborn born to a GBS-positive mother after delivery?

Signs and Symptoms of Early-Onset GBS Disease in Newborns

Approximately 90% of early-onset GBS disease manifests within the first 24 hours of life, presenting primarily as sepsis and pneumonia, regardless of whether the mother received intrapartum antibiotics. 1

Clinical Presentation Timeline

Early manifestation is the rule: The vast majority of infected infants will show signs of illness within the first day of life, with symptoms appearing rapidly after birth. 1

Specific Signs and Symptoms to Monitor

General Sepsis Signs

• Fever or temperature instability - the infant may be febrile or hypothermic 1
• Lethargy and decreased activity - poor responsiveness to stimulation 2
• Poor feeding behavior - refusal to feed or weak suck 2
• Respiratory distress - tachypnea, grunting, nasal flaring, retractions, or apnea indicating pneumonia 1, 3
• Hemodynamic instability - poor perfusion, tachycardia, or hypotension 1

Meningitis-Specific Signs

• Bulging fontanelle 4
• Seizures or abnormal neurologic findings 4
• Irritability or high-pitched cry 4

Note that meningitis occurs in a significant proportion of cases, and blood cultures can be sterile in 15-33% of newborns with meningitis, making lumbar puncture essential when sepsis is suspected. 1

Critical Clinical Context

Maternal Risk Factors That Increase Suspicion

• Chorioamnionitis during labor - this is an important risk factor that can reflect intrauterine onset of infection 1, 5
• Intrapartum fever ≥100.4°F (≥38.0°C) - associated with failure of antibiotics to prevent GBS disease 1, 5
• Prolonged rupture of membranes 6
• Preterm delivery <37 weeks gestation 6

Important Pitfall to Avoid

Do not be falsely reassured by negative maternal GBS screening. More than 60% of early-onset GBS cases occur in infants born to women who had negative prenatal GBS cultures at 35-37 weeks. 1, 7 The screening test has inherent limitations and cannot detect all women with intrapartum colonization. 1

Effect of Intrapartum Antibiotics

Intrapartum antibiotics do not mask or delay the clinical presentation of GBS disease. Multiple studies since 1996 have found no significant difference in clinical presentation between infants exposed to intrapartum antibiotics and those not exposed. 1 Signs of sepsis will still appear within the first 24 hours in most cases. 1

Diagnostic Approach When Signs Present

Perform both blood AND cerebrospinal fluid cultures in any infant with signs of sepsis, as blood cultures alone may miss up to one-third of meningitis cases. 1 This distinction is critical because management differs significantly between sepsis with and without meningitis. 1

Initiate a full diagnostic evaluation immediately, including: 1

• Blood culture
• Complete blood count with differential and platelet count
• Chest radiograph if respiratory abnormalities present
• Lumbar puncture if the infant is stable enough to tolerate the procedure

Begin empiric antibiotic therapy immediately with intravenous ampicillin for GBS coverage plus an aminoglycoside (gentamicin) or cefotaxime for gram-negative coverage, without waiting for culture results. 1, 8, 9