Early-onset neonatal sepsis

The baby is three hours old. Mother is GBS-positive, the membranes went 26 hours ago, and she spiked a fever to 38.7 degrees in the second stage. The midwife brings the baby over because "he's a bit gruntier than he was." That sentence, in this infant, is the whole topic. The window between suspecting sepsis and giving the first antibiotic dose is the window that decides outcome — and most of the time the cultures come back negative and the question becomes one of stewardship, not resuscitation.[1][2]

Overview and definition

Early-onset neonatal sepsis (EOS) is invasive bacterial infection, usually bacteraemia and sometimes meningitis, acquired from the maternal genital tract around the time of birth and presenting within the first 72 hours of life. The same pathogen spectrum produces late-onset sepsis after that cutoff, but the two syndromes have different organisms, different risk factors, and different management reflexes — keep them separate in your head.[1][2]

Modern guidance has moved from the word "sepsis" toward "early-onset bacterial infection" for a reason. Most infants treated empirically never grow an organism; they are suspected, not proven. The clinical skill is not the diagnosis of a positive culture — it is the bedside judgement of which infant to treat, for how long, and when to stop. That judgement is the centre of gravity of every EOS question.[1][3]