Syphilis
Syphilis is a sexually transmitted infection that is easily screened for and cured with antibiotics. However, the presentation of the infection causes some women to completely miss the initial signs; this is critical, as syphilis can lay dormant for years after the original infection.
This is why screening at the first prenatal appointment – and ideally, a preconception appointment – is crucial, as women could have been infected years prior. Further, syphilis can be passed to the fetus during pregnancy, which can occur as early as the first trimester.
This is known as congenital syphilis, which can have devastating complications for the baby, requiring immediate treatment. The number of congenital syphilis cases in the United States has skyrocketed since 2013 (see Background section).
Women should read the below to fully understand the disease, how it infects the body during pregnancy, the complications of congenital syphilis, and how to get tested and treated.
Background
Syphilis is a curable sexually transmitted infection that can cause serious health problems during pregnancy for both mother and baby if left untreated. Possible complications include miscarriage, stillbirth, preterm birth, congenital syphilis, and even infant death.
The World Health Organization estimates that 11 million new cases of syphilis are diagnosed each year globally among adults aged 15 to 49 years; additionally, congenital syphilis remains the most common congenital infection worldwide.
There has been an increase in the number of congenital syphilis cases in the United States (U.S.) after reaching historical lows in the early 2000s. In 2019, the number of congenital syphilis cases in the U.S. was the highest since 1997.
A U.S. Centers for Disease Control and Prevention (CDC) report published in 2021 indicated that during 2012–2019, congenital syphilis rates in the U.S. increased from 8.4 to 48.5 cases per 100,000 births, a 477.4% increase.
According to the same report, "during 2018–2019, the number of syphilitic stillbirths increased (from 79 to 94 stillbirths), as did the number of congenital syphilis related infant deaths (from 15 to 34 deaths)."
"In 2019, the most common missed congenital syphilis prevention opportunity was a lack of adequate maternal syphilis treatment despite receipt of a timely syphilis diagnosis (40.2%)."
"The second most common missed...opportunity was a lack of timely prenatal care and subsequent lack of timely syphilis testing (36.3%)."
Causes
Syphilis is a bacterial infection (T. pallidum) contracted by direct contact with a sore during vaginal, anal, or oral sex; sores can be around the penis, vagina, anus, in the rectum, on the lips, or in the mouth. Although less common, it is also possible to contract the infection through kissing if there is an active oral lesion.
Syphilis cannot be contracted using the same toilet, clothing, eating utensils, bed sheets, doorknobs, or swimming pool as an infected person.
Signs and Symptoms
Syphilis is divided into stages (primary, secondary, latent, and tertiary), with different signs and symptoms associated with each stage. Syphilis is contagious during its primary and secondary stages, and sometimes in the early latent period.
A person with primary syphilis generally has one or more sores (may be firm, round, painless/sometimes unnoticeable) at the original site of infection, called chancre sores, that develop about 2 to 6 weeks after contact.
Sores usually lasts 3 to 6 weeks and heal regardless of whether treatment was received; treatment is still necessary, however, or the infection will move to the secondary stage. Many women may not notice this initial infection stage, especially if the original site of infection is deep in the vagina or rectum.
Symptoms of secondary syphilis include skin rash, swollen lymph nodes, and fever; the rash can show up at the same time as the original sore, or weeks later.
The rash looks like red or reddish-brown spots all over the body, and on the palms of the hands and/or the soles of the feet. The rash is usually not itchy, and may be very faint.
Other symptoms can include sore throat, headaches, weight loss, hair loss, muscle aches, and fatigue. The symptoms from this stage will also go away without treatment. However, without treatment, the infection will continue to the latent and/or tertiary stage.
Signs and symptoms of secondary syphilis disappear within a few weeks but can repeatedly come and go for as long as a year. Secondary syphilis can also last for weeks or months.
There are no signs and symptoms during the latent stage. At this stage, syphilis remains in the body – for years even – with no visible outward signs and symptoms. It is possible symptoms never return, but the infection can also move to the tertiary stage. About two-thirds of untreated syphilis infections remain in the latent stage for life.
The remaining 30% of individuals who contract syphilis and do not get treatment will develop tertiary syphilis, which is associated with severe complications and may affect the heart, brain, blood vessels, liver, bones, eyes, and joints, and can result in death.
Tertiary syphilis usually begins 3 to 30 years after the initial infection. Infections at this stage are usually not contagious, but also rare – as most people today are cured by this stage. It is possible that individuals end up taking the antibiotic necessary to cure syphilis for an unrelated infection that also happens to cure the syphilis they may or may not know they even contracted.
Pregnancy – Overview
All pregnant women should be tested for syphilis at their first prenatal visit. A woman who has syphilis while pregnant can transmit the infection to the fetus at any point during pregnancy. The risk of congenital infection is much higher during untreated primary and secondary stages.
The general time frame in which a woman may go through primary, secondary, and early latent syphilis is approximately 9 months; therefore, complications during pregnancy can vary depending on timing of infection and stage of gestation.
Congenital Syphilis
Congenital syphilis (CS) occurs when a mother with syphilis passes the infection to her baby during pregnancy or during delivery (placenta or through birth canal). CS can occur if a woman has untreated syphilis prior to pregnancy or contracts syphilis during pregnancy.
Congenital infection has been reported as early as 14 weeks of pregnancy (that did not result in miscarriage) and signs of infection can sometimes be observed via ultrasound; the risk of infection increases as pregnancy progresses.
Neonatal outcomes of CS depend on timing of infection, stage of infection, timing of treatment, and the immunological response of the fetus. CS can cause miscarriage, stillbirth, preterm birth, low birth weight, and even newborn/infant death. Other complications include:
Enlarged liver (almost all cases)
Enlarged spleen (half of cases)
Jaundice (yellowing of the skin or eyes) (a third of cases)
Deformed bones
Severe anemia
Brain and nerve problems (blind or deaf)
Meningitis
Skin rashes
Problems with blood clotting
Seizures
Most newborns with congenital syphilis have no symptoms at birth, or only a rash; some get symptoms that develop weeks to years later. Therefore, CS has been traditionally classified as early congenital syphilis (before 2 years) and late congenital syphilis (after 2 years). It is not known why some newborns develop symptoms immediately and why others develop them later in life.
An HCP will test the baby’s blood, request an x-ray, or conduct a spinal tap if CS is suspected. A baby treated for CS may need antibiotics in a hospital for 10 days, others may only need one injection of an antibiotic. Follow up care is mandatory to make sure the treatment worked.
Babies who do not get treatment for CS can die from the infection – all women should be tested during pregnancy, and all women who test positive should be treated.
Diagnosis and Treatment – Mother
There is no vaccine to prevent syphilis, but the test is easily accessible and inexpensive, and treatment (antibiotics) is straightforward. A blood test can determine a current and past infection.
In the U.S., at least 45 states have a prenatal syphilis testing requirement (as of July 2021).
According to July 2021 CDC guidelines for syphilis and pregnancy:
All pregnant women should be screened at the first prenatal visit, even if they have been tested previously, and again at 32 to 36 weeks if mother is at risk of infection based on sexual activity.
Testing in the third trimester and at delivery can prevent congenital syphilis cases.
Partners of pregnant women with syphilis should be evaluated, tested, and treated.
Pregnant women should be retested for syphilis at 28 weeks’ gestation and at delivery if the mother lives in a community with high syphilis rates or is at risk for syphilis acquisition during pregnancy (e.g., misuses drugs or has an STI during pregnancy, having multiple sex partners, having a new sex partner, or having a sex partner with an STI).
The preferred treatment at all stages is penicillin; if a woman is allergic to penicillin, the HCP will select another antibiotic. If the infection occurred less than a year ago, it is possible only one antibiotic injection is needed; older infections may require more than one.
Note: It is possible, especially in later stages, that treatment might not undo any damage the infection has already caused, but it does prevent further damage. Additionally, maternal treatment can be inadequate if delivery occurs within 30 days of starting treatment.
The Jarisch-Herxheimer reaction occurs in up to 44% of pregnant women during treatment. The reaction occurs approximately 2 to 12 hours after receiving treatment and and may last for about a day. It is characterized by fever, headache, muscle pain, and fatigue. This reaction increases the risk of contractions, premature labor, and/or fetal distress or stillbirth (severe cases) if it occurs in the second half of pregnancy.
Women who are diagnosed and treated for syphilis require follow up for at least one year to make sure treatment is working. Women should also avoid sexual contact until the treatment is completed and follow up indicates the infection is gone.
Action
All pregnant women should be screened for syphilis (and other STIs) during their first prenatal visit.
Women should be up front and honest with their HCP regarding their sexual activity and contacts. This will allow HCPs to effectively diagnosis, manage, and treat possible infections. If women are afraid to bring up this topic, this page can be emailed to their HCPs, who will know to softly approach the subject at their next appointment.
If any woman believes she may have contracted an STI during her pregnancy, she should call her HCP immediately for testing and early treatment to prevent possible complications for both her and her baby.
Women who wish to be sexually active during pregnancy should have contact with only one partner, and that partner should be tested as well (especially if the individual is a new sexual contact).
Condoms are a good safe sex practice, but will only prevent syphilis infection if the condom completely covers all sores of the infected partner.
Women should also consider sharing and submitting an experience they may have regarding any sexual transmitted infection during pregnancy.
While this can be understandably private, STIs are common in all women, therefore STIs are commonly discovered during pregnancy. A shared experience can help other women learn additional perspectives regarding this concern, help end the stigma associated with STIs, and can give women courage to talk to their HCP to seek treatment.
Partners/Support
Sexual partners of pregnant women should consider getting tested and treated for syphilis and other STIs. Syphilis can remain dormant for many years, to include well after a new sexual contact/relationship. This is also important, as even if a pregnant woman is tested and treated, she can contract syphilis again if her partner has an active infection.
Partners should also avoid having sex with any other partner while engaging in sexual contact with a pregnant woman, to avoid any possible risk an STI could be given to the pregnant woman (and baby).
Resources
Syphilis Basic Fact Sheet (U.S. Centers for Disease Control and Prevention)
Congenital Syphilis Fact Sheet (U.S. Centers for Disease Control and Prevention)
Chlamydia, Gonorrhea, and Syphilis (American College of Obstetricians and Gynecologists)