This sheet is about having a syphilis infection in a pregnancy or while breastfeeding. This information is based on published research studies. It should not take the place of medical care and advice from your healthcare provider.
What is syphilis?
Syphilis is a sexually transmitted infection (STI) that can cause serious health problems if not treated. Syphilis infection is caused by the bacterium Treponema pallidum (T. pallidum).
People can get syphilis by direct contact with a syphilis sore during vaginal, anal, or oral sex. Syphilis can also be spread through contact with the rash that appears in later stages of the disease. When a pregnant woman has a syphilis infection, the infection can pass to the fetus (vertical transmission). If the fetus is infected, this is called congenital syphilis.
Having syphilis once does not protect you from getting it again in the future, so it is important to lower the risk of getting a new syphilis infection. Sex partner(s) should be tested and, if positive, treated for syphilis right away. Other ways to lower your risk of getting syphilis can be found here: https://www.cdc.gov/syphilis/about/about-congenital-syphilis.html.
What are the stages and symptoms of syphilis?
Syphilis infection is divided into 4 stages. People’s symptoms of syphilis can be different depending on the stage. Some people have no symptoms or only very mild symptoms.
- Primary syphilis: One or more painless sores (called chancres) develop 1 to 12 weeks after exposure to T. pallidum. Sores usually appear in the genital area or the mouth. Most of the time the sores go away on their own. Syphilis can be cured in this stage with the right treatment.
- Secondary syphilis: Appears 4 to 10 weeks after primary syphilis. Symptoms may include rash (usually on the soles of the feet and palms of the hands), flat warts (which may appear on the vulva), fever, swollen lymph glands, sore throat, patchy hair loss, headaches, weight loss, muscle aches, and fatigue (feeling very tired). Symptoms usually go away on their own in 3 to 8 weeks. Syphilis can be cured in this stage with the right treatment.
- Latent syphilis: There are no visible signs or symptoms of syphilis in this stage, even though the infection has not gone away. Syphilis in this stage can only be diagnosed with blood testing. Latent stage is divided into early-latent (no symptoms, but infection happened within the past 12 months) and late-latent (no symptoms, but infection happened more than 12 months ago). Syphilis can be cured in this stage with the right treatment. About 4 out of 10 (40%) people will develop tertiary stage syphilis if not treated.
- Tertiary syphilis: Appears between 5 years to 25 years after the latent stage if Syphilis is not treated. At this stage, syphilis infection can damage many parts of the body and may appear in different forms. Some people develop gummas (soft tumor-like growths) on the skin, bones, or organs. Others develop heart, blood vessel, neurologic (brain) problems. Even with treatment at this stage, some damage may not fully improve.
How can I find out if I have syphilis?
A blood test can be done to find out if you have syphilis. People can have syphilis and not know it. The American College of Obstetricians and Gynecologists (ACOG) recommends that all women who are pregnant get tested for syphilis at their first prenatal visit, during the third trimester, and again at delivery.
Is there treatment for syphilis?
Syphilis infection can be treated and usually cured with antibiotics, such as penicillin. Because syphilis can pass to the fetus if untreated, it is very important to start treatment right away. Use of penicillin during pregnancy is not expected to increase chances for pregnancy problems. MotherToBaby has a factsheet on penicillin here: https://mothertobaby.org/fact-sheets/penicillin-g/. If you have a penicillin allergy, your healthcare provider will go over what treatment is best for you.
I have syphilis. Can it make it harder for me to get pregnant?
It is not known if having syphilis can make it harder to get pregnant.
Does having/getting syphilis increase the chance of miscarriage?
Miscarriage is common and can occur in any pregnancy for many different reasons. Having syphilis increases the chance of miscarriage.
How likely is it that syphilis infection in pregnancy will pass to the fetus?
Syphilis can be passed to a fetus during any trimester of pregnancy. Transmission can also happen during delivery if the baby comes into direct contact with an infected sore.
The highest rates of vertical transmission in pregnancy are reported among women with primary or secondary syphilis in their 3rd trimester of pregnancy.
The rates of vertical transmission are very low (less than 1 out of 100 (less than 1%)) if syphilis is treated in the 1st trimester of pregnancy. This is why early screening and treatment in pregnancy is important.
Does having/getting syphilis increase the chance of birth defects?
Birth defects can happen in any pregnancy for different reasons. Out of all babies born each year, about 3 out of 100 (3%) will have a birth defect. We look at research studies to try to understand if an exposure, like having syphilis, might increase the chance of birth defects in a pregnancy. Before birth, babies with congenital syphilis can develop problems like an enlarged liver or spleen, anemia, an enlarged placenta, too much amniotic fluid (polyhydramnios), or fluid buildup in the body (hydrops). Some of these problems can get better or go away if syphilis is treated.
Does having/getting syphilis increase the chance of other pregnancy-related problems?
Congenital syphilis increases the chance of preterm delivery (birth before week 37), low birth weight (weighing less than 5 pounds, 8 ounces [2500 grams] at birth), or stillbirth.
After birth and up to age 2 years, babies with congenital syphilis might show signs of early infection, including bone problems or swelling of the joint, skin rashes, low blood counts, liver or gallbladder problems, problems with feeding, and jaundice (yellowing of the skin and eyes). Health problems that might be seen later (after the age of 2 years) can include problems with teeth, hearing loss, eye problems and vision loss, and bone or facial differences.
Which problems happen can depend on the stage of the mother’s syphilis during pregnancy and whether she received treatment. It is also possible that a baby with congenital syphilis will not have any symptoms at birth. Since it cannot be predicted which babies will or will not develop problems, monitoring for symptoms may be recommended for any baby whose mother has syphilis or had syphilis during the pregnancy. Getting appropriate treatment for the baby quickly is important to avoid serious problems.
Does having/getting syphilis in pregnancy affect future behavior or learning for the child?
Babies with congenital syphilis can have long-term problems like learning differences, hearing loss, eye and vision problems, and developmental delay (learning skills like talking or walking later than expected).
How can I find out during my pregnancy if my baby will be affected by syphilis?
Prenatal ultrasounds can be used to screen for some health problems related to congenital syphilis, such as slow growth, large placenta, and fluid buildup around the baby’s body. However, most babies with congenital syphilis will not show any signs of infection on ultrasound. Other problems seen with congenital syphilis, such as eye problems or learning problems, cannot be seen on ultrasound and might not be known until the child gets older.
Amniocentesis is a procedure that removes a small amount of fluid from the baby (amniotic fluid). This fluid can sometimes be tested for the bacterium that causes syphilis. Your healthcare providers can talk with you about the availability as well as the risks and benefits of having this test during pregnancy. After a baby is born, their blood can be tested for syphilis.
Talk with your healthcare providers about any prenatal screenings or testing that are available to you. There are no tests available during pregnancy that can tell what symptoms a child with congenital syphilis will have and how severe they may be.
Breastfeeding while I have syphilis:
Syphilis infection cannot be passed through breastmilk. Women with syphilis can breastfeed as long as neither the baby nor pumping equipment touches a sore. If you have sores on your breast, pump or hand-express your milk until the sores heal. Discard the breast milk only if your pump parts touch the sore during pumping.
Penicillin, which is usually used to treat syphilis, is not expected to increase risks to a breastfeeding baby and can usually be used while breastfeeding unless you or your baby are allergic to it. If you or your baby have a penicillin allergy, your healthcare provider will go over what treatment is best for you. Be sure to talk to your healthcare provider about all your breastfeeding questions.
If a man has syphilis, can it affect his fertility or increase the chance of birth defects?
Health complications from syphilis could affect a man’s fertility (ability to make healthy sperm). Men with syphilis can pass the syphilis infection to their partner through sexual contact, which can increase risks to a pregnancy. Men with syphilis should be treated right away. The use of protection (condom) is recommended during sex with males who have syphilis until their treatment is completed. Talk with your healthcare provider as soon as possible if you or your partner has syphilis. For more information, please see the MotherToBaby fact sheet Paternal Exposures at https://mothertobaby.org/fact-sheets/paternal-exposures-pregnancy/.
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