When a newborn develops a fever, it is a serious concern requiring immediate attention. For infants under two to three months of age, a fever can indicate a serious underlying condition. A fever in a newborn is defined as a rectal temperature of 100.4 degrees Fahrenheit (38 degrees Celsius) or higher. This threshold is lower than for older children because a young infant’s immune system is still developing, making them more vulnerable to infections.
Understanding Newborn Fever
Accurately measuring a newborn’s temperature is the first step in identifying a fever. The most reliable method for infants up to three months old is a rectal temperature using a digital thermometer, as it provides the most accurate reading of the baby’s core body temperature. Other methods, such as armpit or temporal (forehead) readings, are less accurate for newborns.
To take a rectal temperature, lubricate the tip of a digital rectal thermometer with petroleum jelly. Gently insert the lubricated tip about one-half to one inch (1.25 to 2.5 centimeters) into the baby’s rectum while they are lying on their back with legs bent towards their chest or on their belly. Hold the thermometer in place until it beeps, then remove it and read the display. A reading of 100.4 degrees Fahrenheit (38 degrees Celsius) or above indicates a fever.
Signs to Seek Immediate Medical Care
A rectal temperature of 100.4 degrees Fahrenheit (38 degrees Celsius) or higher in a newborn under two to three months of age requires immediate medical attention. Even a seemingly mild fever in this age group can be the only sign of a serious bacterial infection, such as sepsis or meningitis, which can progress rapidly. Therefore, if a newborn has a fever, it is recommended to go to an emergency department without delay.
Beyond the temperature itself, several other signs and behavioral changes in a newborn with a fever indicate the need for urgent medical evaluation. These include lethargy, where the baby appears unusually sleepy, difficult to wake, or has little energy and interest in surroundings. Poor feeding, such as refusing to eat or being unable to suck effectively, is another concerning symptom. Changes in breathing, like rapid or difficult breathing, grunting noises, or sucking in of the chest under the ribs, also require immediate attention.
Other urgent signs include a new or unusual rash, particularly small, red, or purple spots that do not fade when pressed. Inconsolable or non-stop crying, a bulging or sunken soft spot on the head, or any signs of dehydration such as fewer wet diapers or no tears when crying, are also serious indicators. Seizures, though rare, can occur with fever in infants and necessitate emergency care. If a newborn looks or acts very sick, appears pale or yellow, or is difficult to calm, these are additional reasons to seek immediate medical help.
Immediate Steps Before Hospital Arrival
Once a newborn’s fever is confirmed and the decision to seek emergency medical care has been made, certain immediate steps can help with preparation. It is important to gather essential items for the hospital visit, such as diapers, wipes, a change of clothes for the baby, and any necessary formula or breast milk. Bringing a comfort item like a favorite blanket or pacifier can also help soothe the baby.
Avoid giving any over-the-counter fever-reducing medications, such as acetaminophen or ibuprofen, to a newborn under three months old without specific medical advice. These medications are often not recommended for very young infants, and their use could mask important symptoms or interfere with diagnostic evaluations at the hospital. Instead, focus on keeping the baby comfortable, such as dressing them in light clothing to prevent overheating.
It is advisable to contact the pediatrician or an emergency medical service before heading to the hospital, if possible. They can provide guidance on the fastest route to care and prepare the medical team for the baby’s arrival. While en route, continue to monitor the baby closely for any changes in their condition, noting any new or worsening symptoms to report to the medical staff upon arrival.
Hospital Care for Newborn Fever
Upon arrival at the hospital with a febrile newborn, parents can expect a thorough diagnostic process aimed at identifying the cause of the fever. Given the potential for serious bacterial infections in young infants, healthcare providers often conduct a “sepsis workup.” This comprehensive evaluation helps to rule out severe infections that could quickly become life-threatening.
The diagnostic process includes a physical examination, along with blood tests and urine tests. Blood samples are taken to check for signs of infection and to perform blood cultures, which can identify the presence of bacteria in the bloodstream. Urine samples, often collected via catheterization to ensure sterility, are analyzed for urinary tract infections. For infants under 28 days old, a lumbar puncture, also known as a spinal tap, may be performed. This procedure involves collecting a small sample of cerebrospinal fluid from the baby’s spine to check for meningitis, an infection of the fluid surrounding the brain and spinal cord.
Initial treatment often involves starting broad-spectrum antibiotics intravenously, even before all test results are back. This approach is a precaution because serious bacterial infections can progress rapidly in newborns, and delaying treatment could have significant consequences. The baby is typically admitted to the hospital for observation, for 24 to 48 hours, while cultures are incubated to see if bacteria grow. If test results indicate no bacterial infection, antibiotics may be discontinued, and the baby may be discharged.