Fever During Pregnancy

What is fever and hyperthermia?

A person's typical body temperature is around 98.6 degrees F (37 degrees C). Fever refers to a temporary rise in body temperature over 101 degrees F (38.3 degrees C). Infection is one of the most common causes of fever. Another common cause is dehydration which is seen quite frequently in early pregnancy due to vomiting

Hyperthermia, or overheating, is a rise in body temperature that happens when the body absorbs more heat than it releases. The most common causes of hyperthermia are heat stroke and severe reactions to medications (malignant hyperthermia). Long exposure to hot temperatures on hot days (often described at 86 degrees F (30 degrees C or higher) can also cause hyperthermia. Extreme exercise or use of hot tubs or saunas might also cause hyperthermia.

A raise in body temperature due to fever or hyperthermia can be of concern in early pregnancy, especially if it lasts for a long period of time.

Having a fever during pregnancy—especially during your 1st trimester, especially more than 100 degrees F —may cause problems for your baby.

In a variety of animal species, hyperthermia in pregnancy has been recognized as teratogenic. Hyperthermia interferes with protein synthesis via heat-shock proteins, which can entail membrane disruption, cell death, vascular disruption, and placental infarction.

Studies have reported a small increased chance for birth defects called neural tube defects (NTDs) in babies of people who had fevers or hyperthermia before the 6th week of pregnancy. Neural tube defects occur when the spinal cord or brain does not form properly. High temperatures that happen after the 6th week of pregnancy are not expected to increase the chance for NTDs related to the fever or hyperthermia. Some cases of microcephaly are also attributed to fever during first trimester.

A few studies have reported a small increased chance for other birth defects when fever or hyperthermia occurs in early pregnancy, especially if the fever is untreated. These include heart defects, abdominal wall defects (an opening in the abdomen through which organs such as intestines or stomach can stick out), or oral clefts (an opening in the upper lip [cleft lip] and/or the roof of the mouth [cleft palate]).

A few studies have reported a small increased chance for problems such as attention deficit disorder (ADHD) and autism when a person had a fever in pregnancy, especially if the fever is untreated. As there can be many things that affect future behavior and learning for a child, it is hard to know if a fever, underlying infection, underlying medical condition causing a fever or hyperthermia, or other factors are the cause of these problems.

It is not known if having a fever or hyperthermia can cause other pregnancy complications. Some underlying illnesses or health conditions that may cause fever could increase the chance for pregnancy-related problems such as preterm delivery (birth before week 37) or low birth weight.

Treatment of fever

The most common medications used to treat a fever are acetaminophen/paracetamol (Pacimol, Dolo -650, Paracip, CrocinAdvance ,Calpol). Most healthcare providers consider acetaminophen to be the fever-reducer of choice during pregnancy. It suggested to use only as needed and at the lowest effective dose.

Can I prevent fever during pregnancy?

Fever is usually a sign of another underlying illness or infection, including cold and flu. Limiting exposure to infections, washing hands often, and staying up to date on vaccinations are some of the best ways to prevent illness and possible fever. Avoid company of those suffering from cold, flu. Hot tub or sauna use during pregnancy should be limited. If you live in or are visiting a hot climate, be sure you take precautions and limit the amount of time you spend in the heat.

Breastfeeding while I have a fever or hyperthermia:

Having a fever or hyperthermia does not seem to affect the ability to breastfeed. If your fever is due to an illness, there are antibodies in the breast milk to help lower the chance that the baby will get sick. Be sure to wash your hands often and wear a mask or try not to breathe directly on the baby’s face while nursing. If your dose of antibiotic coincides with the feed time, give breast feed first and then take your antibiotic.

If you still need more information, please talk to the doctor in the next visit.