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Sepsis in Newborns

(Sepsis Neonatorum; Neonatal Sepsis)


Brenda L. Tesini

, MD, University of Rochester School of Medicine and Dentistry

Last full review/revision Jul 2020| Content last modified Jul 2020
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Sepsis is a serious bodywide reaction to infection spread through the blood.

  • Newborns with sepsis appear generally ill—they are listless, do not feed well, often have a gray color, and may have a fever or a low body temperature.

  • The diagnosis is based on the symptoms and the presence of bacteria, a virus, or a fungus in the blood, urine, or spinal fluid.

  • Treatment involves antibiotics and supportive treatments such as intravenous fluids, blood and plasma transfusions, assistance with breathing (sometimes with a mechanical ventilator), and drugs to support blood pressure.

  • Infection in the bloodstream may spread to the tissues covering the brain and the brain itself (meningitis).

Sepsis is more likely to occur in

Other risk factors for and causes of sepsis differ depending on when sepsis develops. The start (onset) is categorized as

  • Early-onset sepsis: Before 3 days of life

  • Late-onset sepsis: After 3 days or more of life

Certain viral infections, such as widespread herpes simplex, enterovirus, adenovirus, or respiratory syncytial virus, may cause early-onset or late-onset sepsis.

Premature infants are at much higher risk of both early-onset and late-onset sepsis than are infants born at full term because of their immature immune system. Premature newborns lack certain protective antibodies against specific bacteria because they were born before they could receive them from their mother.

Early-onset sepsis

Newborns can develop early-onset sepsis if they are exposed to certain kinds of bacteria during birth.

Risk factors for early-onset sepsis include the following:

The risk of sepsis is greater if the fluid-filled membranes that surround the fetus rupture more than 18 hours before birth or if the mother has an infection (particularly of the urinary tract or lining of the uterus).

The most common types of bacteria causing sepsis in the newborn around the time of birth are Escherichia coli and GBS, which are usually acquired during passage through the birth canal. Sepsis caused by GBS was the leading cause of early-onset sepsis until about a decade ago when screening of all expectant mothers for GBS became a routine part of prenatal care. If screening reveals GBS or if the mother previously gave birth to a newborn who had a GBS infection, the mother is given antibiotics when she goes into labor. Although the newborn may require additional monitoring in the hospital and possibly blood tests to check for infection, newborns are given antibiotics only if they have symptoms or signs of infection.

Late-onset sepsis

Newborns can develop late-onset sepsis if they are exposed to certain kinds of bacteria in the hospital.

Important risk factors for late-onset sepsis include the following:

  • Prolonged use of catheters in arteries, veins, and/or bladder

  • Antibiotic use in the newborn

  • Use of a breathing tube inserted through the newborn's nose or mouth (endotracheal tube) and attached to a machine that helps air get in and out of the lungs (ventilator) to help support breathing

  • Prolonged hospitalization

Sepsis that occurs later is more likely to be acquired from organisms in the newborn's environment, including through or around catheters (a tube doctors use to get fluids or drugs into the newborn's bloodstream, such as an IV, or a tube used to drain urine from the newborn's bladder) and other medical equipment, rather than organisms acquired from the birth canal. The use of certain antibiotics can allow certain organisms such as the fungus Candida to cause infections in the newborn.

Symptoms of Sepsis in Newborns

Newborns with sepsis are usually listless, do not feed well, and often have an unstable body temperature. A fever that lasts for more than an hour is uncommon, but, when present, typically indicates the newborn has an infection.

Other symptoms may include trouble breathing (respiratory distress), pauses in breathing (apnea), pale color, and poor skin circulation, with cool extremities, abdominal swelling, vomiting, diarrhea, seizures, jitteriness, and jaundice. Group B streptococcus infection may cause pneumonia. Other symptoms occur depending on which organism is causing the infection.


One of the most serious complications of sepsis is infection of the membranes surrounding the brain (meningitis). Newborns with meningitis may have extreme sluggishness (lethargy), coma, seizures, or bulging of the soft spot between the skull bones (fontanelle) and often die if not treated promptly.

Diagnosis of Sepsis in Newborns

  • Cultures of blood and sometimes urine

  • Spinal tap with culture of the spinal fluid

Doctors diagnose sepsis based on the newborn’s symptoms and the results of tests. Doctors do several tests, including blood tests, to try to determine the specific bacterium, virus, or fungus that is causing the infection.

A blood culture, sometimes a urine culture, and a spinal tap (lumbar puncture) are also done. For cultures, doctors take samples of blood, spinal fluid, and urine and try to grow (culture) the bacteria in the samples in the laboratory and identify it. Newborns with breathing problems undergo a chest x-ray.

Prognosis of Sepsis in Newborns

Sepsis is the major cause of death in premature newborns after the first week. Low-birth-weight infants have an increased risk of death. Extremely low-birth-weight infants who have sepsis caused by the fungus Candida or bacteria are at much greater risk of death.

Newborns who recover from sepsis generally do not have long-term problems. However, newborns who survive meningitis may have developmental delay, cerebral palsy, seizures, or hearing loss.

Treatment of Sepsis in Newborns

  • Antibiotics by vein (intravenously)

  • Sometimes a ventilator or other treatments

While awaiting blood culture results, doctors give strong antibiotics intravenously to newborns with suspected sepsis. Once they identify the specific organism, they may adjust the type of antibiotic.

In addition to antibiotic therapy, other treatments may be needed, such as use of a machine that helps with breathing (mechanical ventilator), intravenous fluids, blood and plasma transfusions, and drugs that support blood pressure and circulation.

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