Viruses, bacteria, and other germs cause infections. You may be more likely to get one during pregnancy because your immune system is lower. Many do not cause problems. But some can cause problems for you, your growing baby, or both. If you think you have an infection, talk to your doctor right away.

Some of the problems you may have are:


Also called chickenpox , children mostly get this virus. Most pregnant women do not get it. If you have had it before, it is unlikely that you will get it again. If you get chickenpox in the first 20 weeks, there is a very small chance that your baby will be born with health problems. If you get chickenpox around the time of your baby’s birth, your baby may be born with the infection. If this infection is treated, most babies have only a mild sickness. Without care, about a quarter of babies die.


Chorioamnionitis is a rare bacterial infection of the tissue around the amniotic fluid and the baby. It often starts when bacteria in your birth canal or rectum enters your womb. It is more likely to happen after the bag of water has broken. In most cases, having this infection means your baby must be delivered right away.

Cytomegalovirus (CMV)

Cytomegalovirus (CMV) is a common viral infection that most often does not cause problems. When a pregnant woman has it, she can pass it on to her growing baby. In a small number of cases, this leads to serious sickness in the newborn, lasting health problems, and even death.

Group B Streptococcus

Group B streptococcus (GBS) is a type of bacterium. Many people carry GBS, but do not become ill. About a quarter of pregnant women carry GBS in the rectum or birth canal. A growing baby may get it before or during birth if the mother carries GBS. It can result in death. In pregnant women, GBS can cause infections of the bladder and womb, and stillbirth. All pregnant women with GBS are treated with IV antibiotics during labor.


Listeriosisis a rare infection caused by bacteria found in some contaminated foods. Pregnant women are more likely to get it. It can cause serious problems, such as premature delivery , miscarriage , and severe illness or death of your newborn.

Parvovirus B19 Infection

Parvovirus B19 infection (fifth disease) is a common virus that causes a slapped-cheek rash on the face. It happens most often in children. If you have contact with a person who has fifth disease, there are most often no problems for you or your growing baby. Rarely, it can cause a growing baby to have severe anemia (low iron), swelling, stillbirth, or miscarriage.


Rubella (German measles) is a mild sickness in children but it can cause serious health problems in a growing baby. The baby could have eye problems, hearing loss , heart problems, and intellectual disabilities . There is a shot to prevent it.

Sexually Transmitted Infections (STIs)

Some STIs, such as genital herpes , gonorrhea , chlamydia , herpes simplex virus, and bacterial vaginosis , are found in pregnant women. Others, such as HIV and syphilis, are less common in pregnant women. They can cause:

  • Infertility (not being able to get pregnant in the future)
  • Premature labor
  • Premature breaking of the membranes around the growing baby
  • Infection of the womb after birth

Some STIs can be passed from you to your baby before, during, or after birth. Care throughout pregnancy and safety steps during birth can help keep the baby safe.


Toxoplasmosis is caused by a parasite. It lives in the intestine of cats and is shed in cat feces, mainly into litter boxes and garden soil. It can cause serious problems in a growing baby, such as blindness, hearing loss, learning problems, miscarriage, and stillbirth.

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