What Is Congenital Syphilis?

Medically Reviewed by Melinda Ratini, MS, DO on May 03, 2022
5 min read

Congenital syphilis (CS) is a disease that happens when a baby gets syphilis from their mother. “Congenital” means that the infection exists at birth. This can happen if you have syphilis during your pregnancy or vaginal birth. It can lead to severe health issues, or even death, for your baby. To keep your baby safe, it’s crucial that you protect yourself from syphilis before and during your pregnancy.

Congenital syphilis is caused by a bacteria called Treponema pallidum. It’s more likely to affect your baby if you get syphilis during your pregnancy. But you could also pass it to your fetus if you got the infection before pregnancy.

This condition can cause lifelong complications for your baby. CS may affect your child differently based on how long you’ve had syphilis and when you received treatment for it.

CS can lead to issues during pregnancy or after birth. Even though your child may seem healthy when they’re born, they could still develop complications from syphilis later in life if they don’t get treatment.

During pregnancy, congenital syphilis can cause:

Miscarriage. This happens when your baby dies in your womb before 20 weeks of pregnancy.

Low birth weight. This happens when your baby is born under 5 pounds and 8 ounces. Fetal growth restriction (which experts also call growth-restricted, small for gestational age, or small for date) is when your baby doesn’t gain the right amount of weight that they should before birth.

Premature birth. Experts consider your baby premature if they’re born before 37 weeks of pregnancy.

Issues with your placenta and umbilical cord. Your placenta gives your baby food and oxygen through the umbilical cord. It grows in your uterus. Congenital syphilis might make your placenta grow too large and cause the umbilical cord to become swollen. If this happens, your placenta and umbilical cord may not support your baby properly.

Stillbirth. This happens when your baby dies after 20 weeks of pregnancy, before they’re born.

Even if your baby is born seemingly healthy, CS can still lead to some serious issues:

Liver and spleen complications. Your baby may develop certain health issues from congenital syphilis. They may include:

  • Jaundice (your baby’s skin and whites of their eyes look yellow due to a buildup of a substance called bilirubin in their blood)
  • Hepatosplenomegaly (your child’s liver and spleen become swollen)

Neonatal death. This happens when a baby dies within the first 28 days of their life.

Anemia. This condition happens when your baby doesn’t have enough healthy red blood cells to carry oxygen through their entire body.

A rash. Your baby may show a rash on their mouth, genitals, bottom, the soles of their feet, or their hands and face.

Meningitis. This infection causes swelling in your baby’s brain and spinal cord.

Other health issues. Your baby may also develop a fever or a runny nose.

If your baby doesn’t receive treatment for congenital syphilis right away, they could show issues later in life. This could include:

  • Pain and swelling in the bones and joints
  • Saber shin (your baby’s shin curves out)
  • Saddle nose (your baby’s nose is flat)
  • Hutchinson teeth (peg-shaped, spaced out teeth)
  • Vision problems
  • Hearing issues
  • Complications with the nervous system (such as paralyzed arms or legs and seizures)
  • Delays in development (for example, your child may not walk, sit, think, talk, or have social skills by the appropriate age)

Signs of early CS tend to happen at 3 to 14 weeks of age. But they could show up as late as 5 years. They include:

  • Inflammation or hardening of your baby’s umbilical cord
  • Fever
  • Skin problems
  • Rash
  • Low birth weight
  • High levels of cholesterol at birth
  • Meningitis
  • Anemia
  • A higher number of monocytes (a type of white blood cell) in your baby’s blood
  • A larger liver or spleen
  • Jaundice
  • Convulsions
  • Skin shedding that affects your baby’s palms and soles
  • Mental problems
  • Periostitis (inflammation around the bones that lead to tender limbs and joints)
  • A runny nose
  • Hair loss
  • Inflammation in your baby’s eyes
  • Pneumonia

Symptoms of late CS usually show up after the age of 5. They may go undiagnosed until adulthood. These can include:

  • Bone pain
  • Eye disease
  • Hutchinson teeth
  • Interstitial keratitis (blurred vision, abnormal tearing, eye pain, and sensitivity to light)
  • Saddle nose
  • A bony look in the forehead
  • A high-arched palate
  • A short upper jawbone
  • Hearing loss
  • Splitting and cracking around the mouth and bottom

During prenatal care visits (doctor’s appointments that pregnant people go to), your doctor will do blood tests to check for sexually transmitted diseases, like syphilis. If they find that you have syphilis, you need to tell your baby’s doctor about all treatments you’ve had during your pregnancy.

Doctors can use many different tests to check your baby for congenital syphilis. These include:

  • A physical exam
  • Blood tests
  • An eye exam to look at your baby’s vision
  • An X-ray
  • An ultrasound
  • A spinal tap (or lumber puncture) to test your baby’s cerebrospinal fluid (fluid in the brain and spinal cord)

If your baby has congenital syphilis, it’s important that you get them treatment as soon as possible. Prompt treatment and regular medical checkups is necessary to make sure therapy works properly.

Doctors use an antibiotic called penicillin to treat your baby. This medication kills certain infections like CS. They can receive penicillin as a shot or through an intravenous line (called an IV).

Your baby’s doctor may give them different amounts of treatment based on the severity of their infection. Doctors can completely cure some babies of CS. But others may have to get extra treatment for additional health issues from the infection.

Congenital syphilis is preventable. The only way your baby will get it is if you pass it to them during pregnancy or birth. Because of this, it’s important that you protect yourself. To do so, you can:

Practice safe sex or abstain from sex. The only way to prevent syphilis completely is to not have sex. But if you are sexually active, you can lower your risk through safe sex. Only have sex with one person who doesn’t have multiple sexual partners. If you’re concerned that your partner could have an STD, use a condom or other barrier method during intercourse and oral sex.

Get tested. If you think you could have syphilis, tell your doctor as soon as possible and get tested. If you do have the infection, your doctor can put you on treatment. If you get treatment sooner, you and your child will be at a lower risk for complications.

Ask your partner to get tested. You should also have your partner get tested and treated if they have syphilis. If you get treatment, you won’t be infected anymore. But if your partner still has the infection, they could reinfect you.

Go to all your prenatal care visits. Even if you don’t feel bad, you should always go to your doctor’s appointments. You can ask questions about your risk of syphilis and other infections. Your doctor can test you if you believe you’re at risk for an STD.