Understanding STDs in Pregnancy -- Basic Information

How Do STDs Affect Pregnancy?

At your first prenatal visit, your health care provider will perform some standard blood tests. He or she will check for several sexually transmitted diseases (STDs) including syphilis, hepatitis B, gonorrhea, chlamydia, trichomoniasis, and possibly human immunodeficiency virus (HIV), the virus that causes AIDS. Finding out you have an STD can be very frightening. But not knowing, and not getting treatment, can be harmful or even fatal to you or your baby.

The following are some common STDs. If you think you may have been exposed to one or more, or you are unsure, talk with your doctor. He or she is there to help you get the treatment you need during your pregnancy. Remember, even if you are getting treatment for an STD, you can be re-infected by a sexual partner who is not being treated.

Protect yourself from STDs by practicing safe sex: Use condoms and spermicides unless you know for sure that you and your partner are disease-free and monogamous.


The number of women with HIV (human immunodeficiency virus) has been steadily increasing worldwide. Women account for approximately 50% of the 33 to 34 million adults living with HIV/AIDS. Most of them were exposed to it from a male sexual partner; the rest became infected through needles, or other exposure to secretions and blood products. If you become infected with HIV, you may have no symptoms for years. Even so, you carry the virus and can infect others, including your baby if you become pregnant. If you become infected, your body soon starts making antibodies against the virus and you become HIV-positive. That means if your blood were tested, you would test positive for the antibody against HIV. Getting tested is the only way to find out if you are infected.

If you are HIV-positive, you may develop AIDS (acquired immunodeficiency syndrome), which includes a variety of conditions that take hold once your immune system is weakened by the virus, such as infections of your lungs and Kaposi's sarcoma, a rare cancer.


Your baby can contract HIV from you while in your uterus, during delivery, or through your breast milk. More than 90% of children living with AIDS contracted HIV from their infected mothers, either before or during birth, or through breast milk. Many babies get HIV during labor and delivery. Having a cesarean delivery may decrease the chances of your baby getting HIV. A baby born with HIV usually has no apparent symptoms, and problems sometimes do not develop until years later.

If you are HIV-positive and you do not take any medications to prevent transmission of HIV to your baby, there is a 25% chance that your baby will become infected. But if you take medications before and during childbirth, you can reduce that risk to less than 2%.

The American College of Obstetricians and Gynecologists (ACOG) and the CDC recommend that all pregnant women voluntarily get tested for HIV. If you are infected with HIV, or think that there is even a slight chance you may be, it is vital that you tell your doctor immediately so you can be tested and receive antiviral medication, if needed.


Chlamydia is the most common STD in the Western world. Untreated, it can cause preterm labor, preterm rupture of membranes, and postpartum endometritis (inflammation of the lining of the uterus). Babies who are infected during birth can suffer from pneumonia or conjunctivitis, which can lead to blindness if untreated. Some women have no symptoms while others may notice a vaginal discharge or lower abdominal pain or develop pelvic inflammatory disease. Some may not suspect that they have chlamydia, however, until their partner has symptoms such as trouble urinating and discharge from his penis.

Genital Herpes

Genital herpes can be passed from a mother to her baby during a vaginal delivery. Babies who come in contact with genital herpes can suffer damage to their eyes and central nervous systems. A herpes infection in a newborn can become life-threatening, affecting multiple organ systems rather than only the genitals.

The most dangerous situation occurs if a woman gets infected with herpes for the first time during pregnancy (primary infection), especially near delivery. A primary infection around the time of delivery puts baby at a very high risk of infection — as much as one chance in two. A woman who has been previously infected with the virus before pregnancy can have recurring infections, but the risk of her baby becoming infected in pregnancy and during delivery is very small because there is usually less virus present. Her existing antibodies will have crossed the placenta and help protect the fetus against infection.

Women who become infected for the first time often develop symptoms such as genital lesions, ulcerations, enlargement of lymph nodes, and pain. But women who have had genital herpes in the past don't necessarily exhibit symptoms every time the virus becomes active, even though they are contagious. For months or even years at a time, the virus may be inactive. When the virus becomes active, there may be symptoms such as itching and pain before the outbreak of blister-like sores on or around the genital area, or there may be no symptoms at all.


Genital Warts

Genital warts or "condyloma" are caused by the human papillomavirus (HPV). This virus can lie latent, causing no symptoms, for months or years after infection. When an outbreak occurs, warts appear on or near the genitals or anus, or within the vagina. Pregnant women with HPV can have rapid growth of warts. HPV transmission from mother to baby can occur, but is rare. Babies who contract the virus can develop warts on their larynx (voice box) as infants or children — usually by age 5. But HPV is not considered a reason to do a cesarean section unless the warts are large enough to interfere with a vaginal delivery.


Gonorrhea is an STD caused by gonococcus or Neisseria gonorrhoeae. Most people who are infected with gonorrhea have no symptoms and are not aware that they are infected. Sometimes, women may experience vaginal discharge and itching, and both men and women may experience burning during urination. Some women aren't tested and treated until their sexual partner exhibits symptoms of painful urination and a thick, milky discharge from his penis. Untreated, gonorrhea can cause eye problems for a newborn, often leading to blindness. People infected with chlamydia often are also infected with gonorrhea. A pregnant woman with gonorrhea can transmit the infection to her baby during delivery. This can lead to serious infection in the newborn.


If you think you've been exposed to syphilis, it is important to be tested and treated. It can cause miscarriage or stillbirth in pregnant women. Untreated syphilis can also cause long-term problems in the brain, skin, bone, and liver. If a pregnant woman is infected with syphilis, she can transmit it to the fetus, leading to skin lesions or problems with the liver, spleen, bones, or nervous system. The primary symptom of syphilis is a painless genital sore. The sore will go away without treatment, but the bacteria remain in your body. If untreated, syphilis may cause more symptoms including rash, headache, fever, and general discomfort (malaise), and over time, may cause serious damage to the heart and central nervous system. All pregnant women have a routine blood test to screen for syphilis at the first prenatal visit.


Hepatitis B

Hepatitis B infection is caused by the hepatitis B virus (HBV), which spreads through contact with an infected person's blood and other bodily fluids. When you first contract HBV, you may experience fatigue, nausea, vomiting, muscle and joint pain, headache, dark urine, gray stools, a chest cold, and jaundice, but many infected persons don't know they are infected. When you first become infected with HBV, your body will fight the infection and you usually develop antibodies that make you immune. Some people infected with hepatitis B continue to carry the virus, rather than develop immunity, after their initial infection. These "chronic carriers" usually have no symptoms but still can infect others through sexual intercourse or by contact with their blood and other bodily fluids. A chronic carrier may infect her baby during pregnancy or childbirth. If your baby is infected, he or she may suffer serious liver problems. Chronic carriers themselves may develop liver disease and liver cancer.


Trichomoniasis is an infection that can cause yellow-green vaginal discharge and pain with sex or when emptying the bladder. It can increase the risk of having a preterm baby. Rarely, the new baby can get the infection during delivery and have a vaginal discharge after birth.

WebMD Medical Reference Reviewed by Traci C. Johnson, MD on January 16, 2020


SOURCES: American Academy of Family Physicians. National Institutes of Health. National Institutes of Allergy and Infectious Diseases.

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