Introduction

Syphilis is a sexually transmitted infection caused by the spirochete bacterium Treponema pallidum. When contracted during pregnancy, it poses significant risks to both the mother and the developing fetus, including miscarriage, stillbirth, preterm birth, and congenital syphilis. Screening and treatment are essential to prevent adverse outcomes, especially in regions like Sri Lanka, where obstetric guidelines emphasize early detection and management.

Epidemiology and Importance in Pregnancy

Syphilis remains a global public health challenge with rising incidence in several countries, including parts of South Asia . In pregnancy, untreated syphilis is associated with adverse maternal and perinatal outcomes. The World Health Organization estimates that congenital syphilis causes approximately 200,000 stillbirths and neonatal deaths annually worldwide .

The Sri Lankan Ministry of Health mandates universal antenatal screening for syphilis, integrating it within routine prenatal care as per national guidelines . Early antenatal clinic visits facilitate timely diagnosis and management.

Pathophysiology and Risks to Mother and Fetus

Syphilis in pregnancy can be categorized by stages—primary, secondary, latent, and tertiary. The spirochete crosses the placenta from about the 9th to 10th week of gestation, infecting the fetus . The risk of transmission and severity depend on the stage and duration of maternal infection, with early syphilis (primary and secondary) posing the highest risk.

Potential outcomes include:

• Miscarriage or stillbirth
• Intrauterine growth restriction (IUGR)
• Premature rupture of membranes and preterm delivery
• Congenital syphilis presenting with skin lesions, hepatosplenomegaly, bone deformities, neurological impairment, or death

Diagnosis

Syphilis diagnosis in pregnancy relies primarily on serological testing with:

• Non-treponemal tests: Rapid Plasma Reagin (RPR) or Venereal Disease Research Laboratory (VDRL) tests for screening and monitoring treatment response.
• Treponemal tests: Treponema pallidum particle agglutination assay (TPPA) or fluorescent treponemal antibody absorption tests for confirmation .

Serial serological testing during pregnancy is advised if initial tests are negative but risk factors persist.

Treatment

According to Sri Lankan national maternal health guidelines and supported by WHO recommendations, penicillin remains the only effective and safe treatment for syphilis in pregnancy.

• Primary Therapy: Benzathine penicillin G, 2.4 million units intramuscularly once weekly for two or three doses depending on the stage (2 doses for early syphilis, 3 doses for late latent) .
• Management of Penicillin Allergy: If allergic, desensitization to penicillin is strongly recommended, as alternative antibiotics do not effectively prevent congenital syphilis .

Treatment must be completed at least 30 days before delivery to reduce fetal transmission risk.

Follow-Up and Neonatal Care

After maternal treatment, close follow-up includes serial non-treponemal titers every 3 months to monitor response. Persistence or rise in titers suggests reinfection or treatment failure requiring evaluation.

Newborns of treated or untreated mothers require clinical assessment and serological testing. Infants with confirmed or suspected congenital syphilis receive treatment with intravenous or intramuscular penicillin according to local neonatal protocols .

Preventive Measures

• Routine antenatal screening for syphilis at the first visit and in the third trimester for high-risk cases.
• Partner notification, testing, and treatment to prevent reinfection.
• Sexual health education to reduce transmission risks.

Conclusion

Syphilis in pregnancy remains a preventable cause of severe neonatal morbidity and mortality. Sri Lankan maternal health guidelines align with global standards emphasizing early antenatal screening and penicillin treatment to safeguard maternal and child health. Obstetric care providers must maintain vigilance for diagnosis, treatment compliance, and follow-up to achieve optimal outcomes.

References

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