Recognizing and Treating Syphilis in Pregnancy

, , University of South Florida College of Medicine; , , Veteran Administration Hospital.


Medscape General Medicine. 1998;1(3) 

In This Article

Clinical Progression to Congenital Syphilis

Pregnancy itself does not seem to alter the clinical progression of syphilis in the female: As in the nonpregnant woman, the primary lesion (Fig. 2) can appear 10 to 90 days after the causative Treponema pallidum spirochete (Fig. 3) invades, although the usual time to appearance is 21 to 35 days. Even untreated, the primary lesion on the skin or mucous membrane usually resolves in 4 to 8 weeks and the infection enters the latency phase, where only serology reveals the presence of infection. Several weeks following the primary chancre, hematogenous dissemination occurs, resulting in the clinical syndrome of secondary syphilis. The classic features of secondary syphilis are skin rash (generalized, with prominence on the palms and soles), lymphadenopathy, and mucous membrane involvement with mucous patches or condylomata lata. However, a variety of other symptoms can occur, including generalized malaise, fatigue, alopecia, aseptic meningitis, and immune complex glomerulonephritis. Again, the signs and symptoms of secondary syphilis resolve spontaneously without treatment, and the infection then enters the latent phase.

Figure 2. Primary lesion of syphilis. Figure courtesy of Centers for Disease Control and Prevention.
Figure 3. Treponema pallidum, spirochete that causes syphilis. Untreated or inadequately treated syphilis in pregnant women can profoundly affect fetal outcome, resulting in congenital infection, prematurity, or perinatal death. Copyright (c) 1997, Medscape Inc.

Untreated or inadequately treated syphilis in pregnant women can profoundly affect fetal outcome, resulting in congenital infection, prematurity, or perinatal death. Of infants born to mothers with primary or secondary (Fig. 4) syphilis, up to 50% will be premature, stillborn, or die in the neonatal period, with most of the remainder developing signs of congenital disease. The risk of these events seems to be directly related to the stage of maternal infection. Of infants born to women with syphilis in the early latent phase, approximately 35% will be premature, stillborn, or die in the first year of life; another 40% will develop signs of congenital disease. In late latent syphilis, 10% of infants develop signs of congenital disease and up to 10% may be stillborn, but prematurity and neonatal death does not seem to be any higher in women with late latent infection than it is in women not infected with syphilis.[4]

Figure 4. Secondary syphilis (rash). Figure courtesy of Centers for Disease Control and Prevention.

Signs of Congenital Syphilis

Most infants born with congenital disease are free of clinical symptoms at the time of birth, and the problem may not appear for more than 2 years. Congenital disease has been divided into 2 categories: early (occurring within the first 2 years of life) and late (recognized 2 or more years after birth).

The manifestations of early congenital syphilis most often occur within the first 3 to 7 weeks after birth and result from active, disseminated fetal infection and the subsequent inflammatory response. Hepatosplenomegaly/hepatitis, jaundice, lesions on the skin and/or in the mouth (Fig. 5), rhinitis, inflammation of long bones (osteochondritis, perichondritis), adenopathy, and hematologic disturbances (anemia, thrombocytopenia) are typical early manifestations of congenital syphilis. Low birth weight and failure to thrive also may occur. Necrotizing funisitis--an inflammation of the umbilical cord characterized by spiral stripes of red and blue discoloration resembling a "barber's pole"--is a specific sign of congenital syphilis.[1]

Figure 5. Moribund newborn with congenital syphilis. Characteristic features include oral and skin lesions and saddle nose. Figure courtesy of Centers for Disease Control and Prevention.

Lesions of late congenital syphilis often represent scars from undetected, early congenital lesions or a delayed reaction to ongoing inflammation. Vasculitis at the time of birth, for example, damages developing tooth buds and results in abnormalities of the permanent teeth. The upper incisors can be peg-shaped, short, and notched (Hutchinson's teeth), and the first lower molars are poorly developed with multiple cusps (Mulberry molar). Interstitial keratitis can appear as photophobia, pain, or blurred vision first in one eye and then bilaterally, any time between the ages of 5 and 20 years. Eighth-nerve deafness is one of the least common signs of congenital syphilis, but it typically occurs in the first decade of life and may be unilateral or bilateral. Facial abnormalities (saddle nose, protuberant mandible), central nervous system involvement (mental retardation, optic nerve atrophy, seizure disorders), and bone or joint involvement (frontal bossing of the skull, saber shins, hypertrophy of the sternoclavicular joints) are other signs of late congenital syphilis.[1]

The pathogenesis of congenital syphilis is not completely understood, but placental invasion is the presumed major route. In the past, it was believed that the T pallidum spirochete could not penetrate the thick Langhans cytotrophoblast layer of the developing placenta, therefore infection could not occur in the first 20 weeks of gestation. However, it is now known that the Langhans layer persists throughout pregnancy; further, a recent study using polymerase chain reaction (PCR) technology has verified that transmission can occur prior to 20 weeks gestation.[5]


Adequate maternal screening and treatment is the key to preventing congenital syphilis. All women should be screened for syphilis with a nontreponemal test (eg, rapid plasma reagin [RPR] or venereal disease research laboratory [VDRL] test) in the first trimester. Those at high risk should be retested at 28 weeks and again near the time of delivery.[6] The nontreponemal test may be negative during incubation or in early primary syphilis, so that even with appropriate screening some cases may be missed. This test is positive in virtually all cases of secondary syphilis, but very high titers can give a false negative reaction, known as the prozone phenomenon. The prozone effect can be overcome by diluting the serum prior to testing. This is a recognized reason for failure to treat during pregnancy, and clinicians must be aware of this phenomenon.[7]