Fetal and Placental Pathology in Congenital Syphilis: A Comprehensive Study in Perinatal Autopsy.

Introduction: At autopsy, without available serologic information, diagnosing congenital syphilis (CS) relies on identification of Treponema pallidum in tissues. Recognition of clues leading to detection of the organism is important.

Materials And Methods: Autopsy cases with CS were studied for fetal and placental abnormalities.

Results: Twenty-one cases were recruited: 12/21 with identifiable T. pallidum and 9/21 with positive serology and characteristics of CS. 20/21 (95%) demonstrated ≥1 fetal abnormalities. Chronic stress involution of thymus was most common. Hydrops and hepatosplenomegaly were found in >50%. Metaphyseal abnormalities and organ inflammation were found in <30%. Mucocutaneous lesions were lacking. Placental abnormalities were identified in 20/21 (95%). Placentomegaly was most common. Amniotic fluid infection (AFI) was noted in >50%.

Conclusion: Common findings in CS at autopsy include chronic stress involution of thymus, hydrops, and hepatosplenomegaly. Mucocutaneous lesions are uncommon. Common placental findings in fetal deaths due to CS include placentomegaly and AFI.