An infant can be born with syphilis, a severe condition medically known as congenital syphilis. This occurs when the bacterium Treponema pallidum is passed from a pregnant woman to her developing baby. Congenital syphilis represents a wide spectrum of outcomes, ranging from an infected baby who appears outwardly healthy at birth to one who suffers from severe, multi-system illness, stillbirth, or death shortly after delivery. Transmission occurs in utero through the placenta, establishing the disease before the baby is born. The risk is significant, especially if the maternal infection is not promptly diagnosed and treated.
How Syphilis Crosses the Placenta
The infection moves from the parent to the fetus via transplacental transmission. The spirochete bacteria, Treponema pallidum, travels through the maternal bloodstream, eventually reaching the placenta, which acts as the interface between the mother’s and the baby’s circulation. Although transmission can happen at any point during gestation, the risk of fetal infection increases substantially as the pregnancy progresses, particularly after the first 14 weeks.
Once the bacteria cross the placental barrier, they enter the fetal circulatory system, leading to a widespread infection known as spirochetemia. This systemic spread allows the organism to invade virtually every fetal organ, including the liver, spleen, bones, and brain. The severity of the fetal infection depends on the stage of syphilis in the mother.
Pregnant women with primary or secondary syphilis have a much higher concentration of bacteria in their blood, leading to an estimated 60% to 100% chance of transmitting the infection if left untreated. During the latent stages, the risk of transmission is lower but remains substantial, decreasing to approximately 40% in early latent syphilis and around 10% in late latent syphilis. This difference highlights that the bacterial load in the maternal system directly correlates with the likelihood of the baby being infected. The spirochetes cause inflammation and disruption within the fetal tissues, setting the stage for the numerous health complications that follow.
Immediate and Long-Term Health Consequences
The consequences of congenital syphilis are categorized into early and late manifestations, depending on when the symptoms appear. Early manifestations present at birth or within the first two years of life, though many infected infants may initially be asymptomatic. Common early signs include a distinctive rash, often appearing as copper-colored lesions on the palms and soles, and a persistent, often bloody, nasal discharge referred to as “snuffles.”
The systemic infection frequently causes the enlargement of the liver and spleen (hepatosplenomegaly). The bacteria often attack the skeletal system, resulting in bone abnormalities like osteochondritis, which can cause pain and reluctance to move a limb (pseudoparalysis). In severe cases, the infection can involve the central nervous system, leading to neurosyphilis, which may manifest as meningitis, seizures, or developmental delays.
If the infection remains untreated or is treated too late, the long-term effects, known as late congenital syphilis, begin to surface after two years of age and can persist throughout life. These delayed issues often involve damage to developing tissues. A hallmark presentation is Hutchinson’s triad, which includes three distinct problems: deafness due to damage to the eighth cranial nerve, interstitial keratitis leading to corneal inflammation and potential blindness, and characteristic dental deformities like notched upper incisors (Hutchinson’s teeth).
Other late stigmata include saber shins, which are abnormal, forward-bowing deformities of the lower leg bones, and saddle nose, caused by the collapse of the nasal bridge. These permanent complications underscore the importance of early diagnosis and treatment, as the infection can cause irreparable damage. Untreated congenital syphilis is also a cause of adverse pregnancy outcomes, including miscarriage, premature birth, and stillbirth.
Prenatal Screening and Treatment Protocols
Preventing congenital syphilis relies on early and routine prenatal screening. Medical guidelines recommend that all pregnant individuals be tested for syphilis at their first prenatal care appointment, ideally during the first trimester. For those at an increased risk of acquiring the infection during pregnancy, a second test is advised early in the third trimester, around 28 weeks’ gestation, and a third test at the time of delivery.
When a positive syphilis diagnosis is made during pregnancy, the treatment protocol is time-sensitive. The standard and only recommended medication for preventing fetal transmission is Penicillin G. This antibiotic is highly effective because it crosses the placenta, treating both the infection in the pregnant patient and the developing baby.
The specific regimen of penicillin depends on the stage of the mother’s infection, but treatment must be initiated immediately upon diagnosis. For women with a documented penicillin allergy, desensitization is performed under medical supervision so they can safely receive penicillin, as no alternative antibiotic reliably cures the fetal infection. When treatment is administered at least 30 days before delivery, its effectiveness approaches 100%. If an infant is born to a mother who was not treated or was inadequately treated, the newborn must immediately receive a course of penicillin.