The main concern regarding fever in pregnancy is if and how it can harm the baby. Although a high body temperature for a prolonged period of time in a pregnant woman could potentially affect the baby, there are a lot of other considerations which have to be taken into account.

Does a Fever in Pregnancy Harm the Baby?

The likelihood and extent of complications in pregnancy due to a fever will depend upon the :

  • Degree of temperature rise.
  • Stage of the pregnancy.
  • Duration of the fever.
  • Cause of the fever.

On an average, a body temperature of 98.60F (37.5C) is taken as normal. A higher than normal body temperature is known as pyrexia or fever. Refer to the article on What is a Fever? for more information on a normal and high body temperature.

Points to bear in mind

  • A temperature rise above 101F (38.30C) may be worrying.
  • A body temperature above 102F (38.90C) for an extended period of time could become problematic.
  • A temperature above 103F (39.50C) during early weeks of pregnancy (usually the first trimester) may be responsible for a miscarriage, spinal cord or mental defects in the baby.
  • Fever in early pregnancy may cause more harm than fever in late pregnancy.
  • Fever caused by an intrauterine infection can be extremely dangerous for the unborn baby.

Causes of Fever in Pregnancy

Viral Infection

The most common cause of a fever in pregnancy is a viral infection.

  • Influenza – seasonal influenza, H1N1 influenza (swine flu).
  • Common cold.
  • Viral infections such as measles, rubella, chicken pox and others.

Bacterial Infection

  • Urinary tract infection (UTI).
  • Respiratory tract infections such as pneumonia and bronchitis.
  • Tonsillitis.
  • Gastrointestinal infections, commonly associated with diarrhea.
  • Appendicitis.
  • Pelvic infection.

Fever Caused by Pregnancy

Chorioamnionitis is a bacterial infection of the amniotic fluid which  surrounds the baby. Along with fever, there may be abdominal pain accompanied by uterine tenderness and contractions. A foul-smelling amniotic fluid or vaginal discharge may be present. If chorioamnionitis is diagnosed, the baby has to be delivered immediately, no matter what the gestational age, to avoid risk of a neonatal infection.

Travelers’ Fever when Pregnant

There are a number of infectious illnesses that can be contracted while traveling and pregnant women should be more cautious especially if traveling to endemic areas. Some of the common infectious illnesses that may be contracted include :

  • Malaria.
  • Typhoid.
  • Meningitis.
  • Hepatitis.

Pregnant women should also be cautious of a fever after contact with an animal or insect whether there was a bite or sting or not. Refer to Fever After Animal, Insect Bites, Stings, Contact.

Raised Body Temperature in Pregnancy

Hyperthermia caused by :

  • Tanning beds.
  • Hot tubs.
  • Sauna.
  • Exposure to extreme hot weather.
  • Over-exertion.

Risks of Fever in Pregnancy

Possible risks of fever in pregnancy may include

  • Prenatal death.
  • Miscarriage.
  • Neural tube defects, such as spina bifida.
  • Micropthalmia (abnormally small eyes).
  • Cataract.
  • Microencephaly (head is significantly smaller than normal).
  • Functional and behavioral problems.
  • Craniofacial developmental defects, such as cleft palate and/or lip.
  • Problems with teeth and skeletal development.
  • Cardiac developmental defects.
  • Preterm delivery.
  • The relationship between problems of CNS function (such as mental retardation, autism, schizophrenia, and cerebral palsy) and fever during pregnancy is still being researched extensively.
  • Risks may be associated with cause of fever rather than the fever itself, such as congenital defects produced by the following infections – TORCH (toxoplasma, others, rubella, cytomegalovirus, and herpes). Included in the “others” category is parovirus B19, chicken pox, measles, enterovirus, adenovirus, hepatitis, and HIV.
  • Refer

Investigations

Investigations to find the cause of fever may be necessary, such as :

  • Blood test, including white blood count.
  • Blood culture.
  • Strep throat culture.
  • Sputum test.
  • Urinalysis.
  • Urine culture.
  • Stool test.
  • Spinal tap or lumbar puncture.
  • If chorioamnionitis is suspected, amniocentesis for microscopy and culture may be needed.

Warning Signs of Fever in Pregnancy

Any fever in pregnancy, especially if lasting more than 24 to 36 hours, should be brought to the doctor’s notice. The presence of the following signs and symptoms along with a fever should be taken seriously.

  • Abdominal pain.
  • Uterine tenderness.
  • Uterine contractions.
  • Nausea and/or vomiting.
  • Diarrhea.
  • Skin rash.

Treatment of Fever in Pregnancy

  • Medication should be taken only after consulting with a doctor. All drugs are not safe for use during pregnancy.
  • Antipyretics to reduce the fever.
    • Acetaminophen is usually recommended.
    • Ibuprofen should not be taken by pregnant women.
  • Cooling blankets or cooling fans to treat hyperthermia.
  • Drink plenty of fluids to avoid dehydration.
  • Adequate rest and enough sleep.
  • Wear loose, comfortable clothes.
  • Stay in a cool environment.
  • The cause of fever has to be determined.
  • Appropriate treatment of the cause of fever, including antiviral medication for viral infections and antibiotics in case of a bacterial infection.
  • A UTI is common during pregnancy. If a woman has had more than one such infection or a kidney infection, she may be advised to take antibiotics throughout pregnancy to prevent the chance of recurrence.
  • Uterine activity should be monitored and fetal well-being assessed by the doctor.
  • Delivery may become necessary in some cases.

Prevention of Fever in Pregnancy

While prevention of fever in pregnancy may not altogether be possible, certain precautions can be taken.

  • Vaccination against seasonal influenza and H1N1 influenza (swine flu) is recommended.
  • Be up to date on all vaccinations.
  • Avoid close contact with people who are sick.
  • Wash the hands frequently with an antiseptic soap.
  • Do not drink unpasteurized milk.
  • Tanning beds, hot tubs and saunas and should be avoided during pregnancy.
  • Preventive medicines should be taken as necessary, when traveling to another country.

Related Article

  1. Sudden Fever – Causes of Acute Fever in Adults

Article reviewed by Dr. Greg. Last updated on September 13, 2010