Sexually transmitted infections


  • Sexually transmitted infections are infections you can get from having unprotected sex with someone who’s infected.

  • If you’re pregnant and have an STI, it can cause serious problems for your baby, including premature birth and birth defects.

  • If you’re pregnant, you get tested for STIs as part of prenatal care. If you have an STI, getting treatment early can help protect your baby.

  • Ask your partner to get tested and treated for STIs.

  • The best way to protect your baby from STIs is to protect yourself from infection.

What is a sexually transmitted infection? 

A sexually transmitted infection (also called STI) is an infection that you can get from having sex with someone who is infected. You can get an STI from unprotected vaginal, anal or oral sex. And you can get an STI during pregnancy—being pregnant doesn’t protect you from getting infected.   

Many people with STIs don’t know they’re infected because some STIs have no signs or symptoms. Nearly 20 million new STI infections happen each year in the United States.  

Can you pass an STI to your baby during pregnancy?

Yes. You can pass some STIs to your baby during pregnancy or vaginal birth. Vaginal birth is when contractions in your uterus (womb) help your baby out through the birth canal. Getting early and regular treatment for an STI can help prevent you from passing it to your baby.

What problems can STIs cause for your baby during and after pregnancy?

STIs can cause serious problems during pregnancy, including:

  • Premature birth. This is birth that happens too early, before 37 completed weeks of pregnancy. Premature babies can have serious health problems at birth and later in life
  • Premature rupture of the membranes (also called PROM). This is when the amniotic sac breaks early. The amniotic sac is the sac or bag inside the uterus that holds a growing baby. The sac is filled with amniotic fluid.
  • Low birthweight. This is when a baby is born weighing less than 5 pounds, 8 ounces
  • Birth defects. These are health conditions that are present at birth. Birth defects change the shape or function of one or more parts of the body. They can cause problems in overall health, how the body develops, or in how the body works.
  • Ectopic pregnancy. This is when a fertilized egg implants itself outside of the uterus (womb) and begins to grow. It can cause serious, dangerous problems for the mom and always ends in pregnancy loss. Most of the time, ectopic pregnancies are removed by surgery. 
  • Miscarriage. This is when a baby dies in the womb before 20 weeks of pregnancy. 
  • Stillbirth. This is when a baby dies in the womb after 20 weeks of pregnancy.

STI infection during pregnancy can cause problems for your baby after birth, too, including problems with the eyes, lungs and liver. Some of these problems can affect your baby’s entire life. Some STIs can even cause a baby’s death. 

Also, being infected with an STI makes it easier for a person to get infected with HIV. HIV stands for human immunodeficiency virus. It’s a virus that attacks the body’s immune system. In a healthy person, the immune system protects the body from infections, cancers and some diseases. Over time, HIV can destroy the cells in the immune system so that it can’t protect the body. When this happens, HIV can lead to AIDS (acquired immune deficiency syndrome).

How do you know if you have an STI?

At your first prenatal care visit, your health care provider does a blood test to check for STIs including: 

If you think you may have an STI, tell your provider right away. Early testing and treatment can help protect both you and your baby.  

How can you protect yourself and your baby from STIs? 

Here’s what you can do:

  • Don’t have sex. This is the best way to prevent yourself from getting an STI.
  • If you do have sex, have safe sex. Have sex with only one person who doesn’t have other sex partners. If you’re not sure if your partner has an STI, use a barrier method of birth control, like a male or female condom or a dental dam. A dental dam is a square piece of rubber that can help protect you from STIs during oral sex. 
  • Go to all your prenatal care checkups, even if you’re feeling fine. You may have an STI and not know it. If you think you may have an STI, tell your provider so you can get tested and treated right away. 
  • Get tested and treated. The sooner you’re treated, the less likely you and your baby are to have complications from your infection.
  • Ask your partner to get tested and treated. Even if you get treated for an STI, if your partner’s infected he may be able to reinfect you (give you the infection again). Ask your partner to get tested and treated to protect you from infection and reinfection.

More information

Last reviewed: February, 2017