A 39-week-gestation newborn shows signs of shock and thermal instability. What infection should be suspected?

In neonates, particularly those who are 39 weeks gestation, presenting with signs of shock and thermal instability, the most concerning diagnosis to suspect is a Streptococcus agalactiae (Group B Streptococcus or Strep B) infection. This bacterial infection is known to be a leading cause of early-onset sepsis in newborns, often manifesting within the first week of life.

Group B Streptococcus can lead to severe illness, including pneumonia, meningitis, and septicemia. The signs of shock (like poor perfusion and changes in heart rate or blood pressure) can be attributed to disseminated infection and the body's inflammatory response. Thermal instability is also a hallmark of infection in neonates, as their ability to thermoregulate is compromised during illnesses.

Infections like Strep B may present acutely and require prompt diagnosis and treatment to prevent severe complications. Understanding the signs associated with this infection, particularly in the context of a full-term infant, highlights its importance in neonatal care.

Other options presented do not fit the acute presentation as effectively as Strep B infection. Pierre-Robin Syndrome primarily affects airway management without direct signs of sepsis or shock. Necrotizing enterocolitis typically occurs in premature infants