The information provided below is for readers based in the United States of America. Readers outside of the United States of America should seek the information from local sources.

What is syphilis?

Syphilis is a sexually transmitted infection (STI), and also a congenitally transmitted disease, resulting from infection by Treponema pallidum, a bacterial species that belongs to a group of bacteria called Spirochaetes, which are distinct in that they are corkscrew or spiral-shaped and have a double-membrane surrounding them. Syphilis develops in a series of distinct stages. The first stage, called primary syphilis, shows up around 3 weeks after contact with an infected person as a sore called a chancre on the skin at the location where the T. pallidum penetrated into the body. About 2-8 weeks after the chancre heals, secondary syphilis begins as the spread of the bacteria through the blood causes symptoms throughout the body, especially the nervous system. This also is called neurosyphilis and it can be followed by a latent period, during which the person does not experience symptoms, but can have occasional relapses. There is a late phase of the latent period (sometimes called late latent syphilis) that is important in connection with pregnancy because its a time when the disease can be transmitted to the developing baby (prior to this, the immune system keeps the bacteria in check). Finally, there is a late stage of the disease, called tertiary syphilis that can develop 1 20 years after the initial infection. This phase can involve more effects in the nervous system, called late neurosyphilis, which can include meningitis (inflammation of the layers covering the brain, called meninges), and problems in the blood vessels of the meninges. Another aspect of tertiary syphilis is cardiovascular syphilis, which includes problems with the valve between the heart and the large artery called the aorta, aneurysm (ballooning out) of the aorta, and narrowing of the openings into the coronary arteries.

How common is syphilis during pregnancy?

In the United States, there were 23,872 cases of primary and secondary syphilis reported in the year 2015. This corresponds to a rate of 7.5 cases per 100,000 people and it represented an increase in the occurrence of syphilis compared with previous years. Although men are infected with T. pallidum more often than women, the disease begins in sexually active people (as well as in infants infected from the mother congenital syphilis) of both genders, so the disease can easily co-exist with pregnancy. Syphilis in the US occurs 5.6 times more often in African Americans than in Caucasians.

How is syphilis diagnosed?

Doctors will have a strong suspicion that you may have primary or secondary syphilis, based on a history that includes either a high number of sexual contacts or sexual contact with a partner who has had syphilis. Along with the history, the presence of a chancre, usually in the genital area, will suggest primary syphilis, as will the presence of enlarged lymph nodes. With secondary syphilis, numerous signs can provide a clue, including a rash on the torso, arms and legs, soles and palms, patches of mucus in the mouth, particular lesions around the genitals and anus, patches of baldness, and various features in the eyes. Tertiary syphilis also shows various signs in the heart and in mental function, slurred speech, and several features in the eyes.

Diagnosis of syphilis is made in the laboratory, first with one of two blood tests, either a VDRL or a rapid plasma reagin test. These are called nontreponemal serologic tests and pregnancy can cause false positives, meaning that they can come out positive when you actually dont have a syphilis infection. However, diagnosis is confirmed either by observing the T. pallidum organism on whats called darkfield microscopy or after performing a polymerase chain reaction (PCR) to amplify DNA whose sequence then can be read to identify the organism. When neurosyphilis is suspected, samples of fluid from around your spinal cord must also be taken (through a procedure called a lumbar puncture) so it can be analyzed. When cardiovascular syphilis is suspected, radiograph images of the chest will be taken and various heart tests will be conducted. If syphilis is confirmed, tests for other STDs also must be conducted.

Does syphilis cause problems during pregnancy?

Secondary syphilis can produce a kind of meningitis (inflammation of the layers covering the brain, which can lead to inflammation of the brain itself with invasion into the brain of T. pallidum) and problems with the cranial nerves (nerves that control and sense different areas of the head, including the eyes, throat and facial muscles, and ears), and can put you on course for late neurosyphilis as part of tertiary syphilis and which can lead to paralysis and affect mental function. Late syphilis also includes severe problems of the heart and the aorta, the major vessel carrying blood from the heart, with potentially fatal consequences. Secondary syphilis also can lead to dysfunction of the kidneys, and tertiary syphilis also can produce problems in the bones. Additionally, the disease can destroy parts of the skin and underlying soft tissues.

Does syphilis during pregnancy cause problems for the baby?

During the late latency period, T. pallidum can spread through the placenta and infect the developing baby, leading to congenital syphilis. This can cause stillbirth, or leave a surviving newborn very small, with a rash, and with various defects in the bones and teeth.

What to consider about taking medications when you are pregnant:

  • The risks to yourself and your baby if you do not treat the syphilis
  • The risks and benefits of each medication you use when you are pregnant
  • The risks and benefits of each medication you use when you are breastfeeding

What should I know about using medication to treat my syphilis during pregnancy?

The preferred treatment is penicillin G, which must be injected not taken orally and it is not considered dangerous in pregnancy. There is an alternative medication, called doxycycline for people who are allergic to penicillin, but it cannot be given to pregnant women, so in the case of penicillin allergy pregnant women sometimes are given desensitization treatment in order to make it possible to receive penicillin while being monitored. Other categories of antibiotic drugs that can be used are macrolides and cephalosporins.

Who should NOT stop taking medication for syphilis during pregnancy?

Everyone who has syphilis must take the appropriate medication. In the early stages, syphilis is curable, but if it is ignored it can lead to irreversible damage to organs and threaten life.

What should I know about choosing a medication for my syphilis during pregnancy?

You may find Pregistrys expert reports about the individual medications to treat syphilis here. Additional information can also be found in the sources listed at the end of this report.

What should I know about taking a medication for my syphilis when I am breastfeeding?

Penicillin G given to a breastfeeding mother is considered safe for a nursing infant, as are some (but not all) of the alternative medications.

What alternative therapies besides medications can I use to treat my syphilis during pregnancy?

There are no alternatives to antibiotics for treating syphilis. In the past, prior to the discovery of p
enicillin, people who got syphilis simply went through from early to late stages of the disease. This led to pain, disfigurement, and many people ultimately succumbed to the cardiovascular and neurological complications. Along the way, they infected sex partners and newborn infants.

What can I do for myself and my baby when I have syphilis during pregnancy?

Follow recommendations from your doctor and refrain from unprotected sex until you are declared free of the infection. In addition to complying with medication recommendations, you need to show up for monitoring of your condition. Notify your sexual partner/s of your condition. Whether or not you have ever had syphilis, keep in mind that the spread of the disease can be prevented through safe sex practices.

Resources for syphilis in pregnancy:

For more information about syphilis during and after pregnancy, contact (800-994-9662 [TDD: 888-220-5446]) or read the following articles:


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General information

It is very common for women to worry about having a miscarriage or giving birth to a child with a birth defect while they are pregnant. Many decisions that women make about their health during pregnancy are made with these concerns in mind.

For many women these concerns are very real. As many as 1 in 5 pregnancies end in a miscarriage, and 1 in 33 babies are born with a birth defect. These rates are considered the background population risk, which means they do not take into consideration anything about the health of the mom, the medications she is taking, or the family history of the mom or the baby’s dad. A number of different things can increase these risks, including taking certain medications during pregnancy.

It is known that most medications, including over-the-counter medications, taken during pregnancy do get passed on to the baby. Fortunately, most medicines are not harmful to the baby and can be safely taken during pregnancy. But there are some that are known to be harmful to a baby’s normal development and growth, especially when they are taken during certain times of the pregnancy. Because of this, it is important to talk with your doctor or midwife about any medications you are taking, ideally before you even try to get pregnant.

If a doctor other than the one caring for your pregnancy recommends that you start a new medicine while you are pregnant, it is important that you let them know you are pregnant.

If you do need to take a new medication while pregnant, it is important to discuss the possible risks the medicine may pose on your pregnancy with your doctor or midwife. They can help you understand the benefits and the risks of taking the medicine.

Ultimately, the decision to start, stop, or change medications during pregnancy is up to you to make, along with input from your doctor or midwife. If you do take medications during pregnancy, be sure to keep track of all the medications you are taking.

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