Fever in Newborn Babies

In newborn babies and young infants three months of age or under, fever is important as it may be the first and only sign of a serious infection. If you notice a temperature that is even just slightly above the normal range – 38°C (101°F) taken rectally or 37.5°C (99.5°F) taken under the armpit – bring your newborn baby to the doctor as soon as possible. Also bring your newborn baby to the doctor if he has any of the following symptoms:

• he is crying inconsolably
• he is listless or limp
• he is having convulsions
• his fontanelle, the soft spot at the top of his head, is starting to swell
• he seems as if he is in pain
• he has developed purple splotches on his skin, or another type of rash
• he is pale or flushed
• he is having problems breathing
• he is refusing to breastfeed or drink from a bottle
• he appears to have trouble swallowing
• he is vomiting or has diarrhea

What causes fever?

Fever is usually a sign that your newborn baby’s body is fighting an infection. Bacteria and viruses usually thrive at a temperature near our normal body temperature. When we have a fever, our body temperature is elevated, which makes it harder for bacteria and viruses to survive. Fever also activates the immune system and sets the infection-fighting white blood cells into action. Usually, fever is associated with common illnesses such as colds, sore throat, or ear infections, but occasionally it can be a sign of something more serious.

How to take your newborn baby’s temperature

There are two ways to take your newborn baby’s temperature: rectally or under his armpit. Do not use a mercury-filled thermometer. The most accurate of these methods is the rectal way; however, many parents do not find this approach very appealing. Here are a few tips for taking your newborn baby’s temperature:

Measuring temperature rectally using an electronic thermometer

• Lay your newborn baby on his back and bring his knees up over his abdomen.
• It is much easier to take a baby’s temperature if two people are doing it.
• Make sure the thermometer is clean.
• Dip the thermometer in some water-soluble jelly.
• Insert the thermometer into your newborn baby’s bottom, about 2.5 cm (1 inch) in.
• Wait for the thermometer to take the reading. This is usually indicated by a beep. Read the temperature carefully and write it down in a notebook.
• Clean the thermometer after use with soap and water.
• The normal range for a temperature taken rectally is 36.6°C to 38°C (97.9°F to 101°F).

Measuring temperature under the armpit

• Place the bulb of the thermometer in your baby’s armpit, and hold his arm down alongside his body. Make sure the bulb is completely covered in the armpit.
• Wait for the thermometer to take the reading.
• The normal range for a temperature taken under the armpit is 36.7 to 37.5°C (98.0 to 99.5°F).

Oral thermometers are not recommended until about age four. Ear thermometers should not be used in newborn babies and young infants because they tend to give inaccurate readings in the very young. Ear thermometers can be used over age two years. Fever strips, which are placed on the child’s forehead, are also not recommended due to inaccuracy.

Treatment of fever in newborn babies

Do not attempt to use medication to treat a fever by yourself if your newborn baby is less than one month of age. Bring him to the doctor instead. The doctor might recommend that you give your newborn baby acetaminophen, but he will need to specify the exact dosage required.

In the meantime, you can continue to breastfeed or bottle feed your newborn baby as normal, if he will take it. If he is showing signs of dehydration — dry mouth, less than six wet diapers per day, tearless and sunken eyes, a sunken fontanelle, or dry skin — you may need to give him an electrolyte solution in between feedings, or replace the feedings with the electrolyte solution. Check with your doctor to make sure.

You can also try giving your newborn baby a sponge bath with lukewarm water. If you let the water evaporate off his skin, it will help to cool him down. Do not add alcohol to the water.

When a newborn baby develops a fever associated with infection, it can become a great cause for concern. This is because newborn babies can get sick very fast. Luckily, they also respond very quickly to treatment, if the infection is caught in time. This is why it is important to bring your newborn baby to the doctor as soon as possible. If a doctor suspects that a newborn baby has an infection, he may begin antibiotic treatment right away.