Changes in the respiratory system can also make pregnant women more vulnerable to colds and the flu, and a fever is a common symptom of these conditions.
A person has a fever when their body temperature rises to 100.4°F (38 °C) or higher. Symptoms that commonly occur with a fever include:
A fever usually indicates that the body is trying to fight off infection. As a result, anyone experiencing a fever or other symptoms of illness during pregnancy should contact a doctor as soon as possible.
The doctor can help rule out underlying conditions and may be able to prevent complications that could affect the developing baby.
Early signs of pregnancy
The body is at greater risk of infection during pregnancy.
The body goes through many changes during pregnancy. As soon as a person conceives, the body begins to prepare for the months ahead.
Pregnancy symptoms can vary — some women may experience certain symptoms and not others, or even no symptoms at all.
Some early signs of pregnancy are:
- A missed period. One of the first and most common signs of pregnancy is a missed menstrual period. However, a missed period does not necessarily mean that a person is pregnant.
- Implantation bleeding and spotting. Bleeding can occur as the egg attaches to the womb. Spotting is light bleeding that usually does not last as long as an average menstrual period. The fluid is typically pale pink or brown. Although vaginal bleeding is common in the first trimester, affecting 15–25 percent of pregnant women, it is a good idea to report it to a doctor.
- Headaches and dizziness. Increased blood flow and hormonal changes can result in headaches, dizziness, or fainting.
- Sore breasts. Tender, swollen breasts can result from hormonal changes in early pregnancy. The nipples may appear swollen, and the breasts may tingle and feel heavy and full.
- Nausea and vomiting. People tend to call nausea and vomiting in early pregnancy "morning sickness," though the symptoms can strike at any time of day or night.
- Fatigue. Feeling exhausted is a common symptom, particularly in the first trimester. Hormonal changes can make a person feel more tired.
- Frequent urination. In early pregnancy, frequent urination results from the release of human chorionic gonadotropin (hCG), a hormone that increases blood flow to the pelvic area. Also, in later pregnancy, the womb expands and can push on the bladder.
- Food cravings. A pregnant woman may start craving particular foods, having aversions to others, or become sensitive to specific smells.
- Mood swings. Hormonal changes can lead to mood swings, and a person may feel happy one moment and very low moments later.
- Nosebleeds and bleeding gums. Increased blood flow during pregnancy can cause these symptoms.
- Nasal congestion. The blood vessels in the nasal passages can expand in early pregnancy, leading to congestion. Nasal congestion can also occur with a cold or the flu.
Several early symptoms of pregnancy can accompany hot flushes, and they may occur with a fever, in some cases.
Why do these symptoms occur?
When a woman becomes pregnant, the body's volume of blood increases. Having more blood can make a person feel warmer and even sweat more.
By around 6 weeks of pregnancy, the volume of blood in the body has increased. The extra blood helps the placenta develop, and this is essential in ensuring a separate supply of blood to the fetus and providing it with nourishment.
By week 16 of pregnancy, the flow of blood plasma to the kidneys rises by 75 percent and continues to increase until the pregnancy reaches full term.
This extra blood flow means that metabolism speeds up, creating more body heat. For this reason, a woman is likely to feel warmer during pregnancy.
The body goes through a considerable number of other changes during pregnancy. Hormone levels fluctuate, the womb expands to make room for the growing baby, and a whole new organ, the placenta, grows to support the fetus.
Pregnancy symptoms occur because of these changes, though not all people experience the same symptoms. Some women hardly notice any symptoms.
How to know for sure if you are pregnant
Pregnancy tests are usually highly accurate.
The only way to be certain of pregnancy is to take a test. Most pregnancy tests claim to be up to 99 percent accurate, though accuracy depends on many factors, such as timing and following the instructions correctly.
After a woman becomes pregnant, the level of the hormone hCG starts to rise. If a person takes a test too early, the levels may not yet be detectable.
To increase the accuracy of a pregnancy test, wait until after a missed period and take the test in the morning, when the urine is less diluted.
Many shops, pharmacies, and doctors' offices offer pregnancy tests. A doctor can also confirm pregnancy with an ultrasound scan.
Pregnancy tests are also available to purchase online.
When to see a doctor
Feeling warm or having occasional hot flushes can be an early sign of pregnancy. Anyone who suspects that they are pregnant should take a test or see a doctor.
Feeling feverish can be a regular result of changes during pregnancy. However, a pregnant woman with a temperature of 100°F or higher should contact a doctor, who can check for underlying causes and monitor the health of the fetus. This is especially important if the fever accompanies other symptoms of illness.
Developing a fever during pregnancy can harm the fetus. With a medical evaluation, a healthcare professional can determine the extent of the risk.