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Neonatal sepsis
Overview
Neonatal sepsis is a serious infection affecting a baby during the first weeks of life. Signs can be subtle, so suspected sepsis requires urgent hospital assessment.
Babies develop rapidly, and the same condition can look different from one child to another. This guide supports informed conversations with a health professional; it cannot diagnose a baby or replace individual care.
Signs and symptoms
Temperature instability, poor feeding, sleepiness, irritability, breathing difficulty, colour change, vomiting, a weak cry or fewer wet nappies may occur.
Parents know their baby best. A change in feeding, alertness, breathing, colour, temperature or wet nappies can be as important as one isolated sign, especially in the newborn period.
Causes
Bacteria and, less often, viruses or fungi can be acquired before, during or after birth. Prematurity and prolonged rupture of membranes can increase risk.
Risk factors
Risk depends on the condition. Prematurity, a difficult birth, infection exposure, feeding difficulties, family history or another medical condition may matter, but many affected babies have no obvious risk factor. Risk factors do not confirm a diagnosis.
Diagnosis
Clinicians rapidly examine the baby and may take blood, urine or spinal-fluid samples while monitoring breathing, circulation and glucose.
A clinician may review pregnancy and birth history, feeding, growth and symptom timing before examining the baby. Tests are chosen only when the history or examination suggests they will help.
Treatment options
Antibiotics are usually started promptly when bacterial sepsis is suspected, then adjusted to test results. Support for breathing, fluids and blood pressure may be needed.
Medicines, specialised feeds, procedures or monitoring should be used only on advice from the baby’s healthcare team. Never give a newborn over-the-counter medicine unless a qualified professional has confirmed the product and dose.
Home care
Keep a simple record of feeds, wet and dirty nappies, sleep, temperature when advised, and changes in symptoms. Follow safer-sleep guidance, wash hands before baby care, attend follow-up appointments and ask for help if feeding is painful or ineffective.
Prevention
Not every condition can be prevented. Antenatal care, recommended newborn screening, smoke-free surroundings, good hand hygiene, safe preparation of feeds, scheduled immunisation and prompt assessment of an unwell baby can reduce avoidable harm.
Possible complications
Most mild newborn problems improve without lasting effects, while some conditions need prompt treatment to protect feeding, growth, breathing, hearing or development. The healthcare team can explain the outlook for the individual baby and arrange follow-up when needed.
When to seek urgent medical care
Treat any concern about neonatal sepsis as urgent, especially fever or low temperature, breathing difficulty, marked sleepiness, mottled colour, poor feeding or reduced responsiveness.
Seek urgent help for a baby who is difficult to wake, unusually floppy, struggling to breathe, turning blue or very pale, having a seizure, repeatedly vomiting green fluid, feeding much less, or producing notably fewer wet nappies. A fever or abnormally low temperature in a young baby needs prompt professional advice.
Frequently asked questions
Is this my fault?
No. Newborn conditions usually arise from development, feeding, infection, birth-related factors or causes outside a parent’s control.
Can I continue feeding my baby?
Often yes, but the safest plan depends on the condition and how well the baby feeds. Ask promptly if feeds are tiring, painful, repeatedly vomited or much shorter than usual.
When should I arrange follow-up?
Use the timeframe given by the maternity, neonatal or primary-care team. Arrange an earlier review if symptoms worsen, feeding changes, growth is a concern or you remain worried.
Summary
Fast recognition and hospital treatment are essential for neonatal sepsis. Early assessment is especially important in young babies because they can become unwell quickly.
References
OUR REVIEW PROMISE
Evidence-based, clearly reviewed.
Healthier Baby Today articles are reviewed for accuracy and updated as guidance changes.
Last updated: July 17, 2026
