[Congenital syphilis despite prenatal screening? An evaluation of 14 cases].

Background: Congenital syphilis (CS) can be effectively avoided by adequate treatment of the mother during pregnancy. Nevertheless, in recent years, the Robert Koch Institute has reported 6-8 of CS cases per year. The aim of this study was to investigate cases of CS with regard to obstetrical history and results of maternal syphilis serology during pregnancy and postpartum.
Patients and Methods: Between 1997 and 2001, a total of 14 cases of CS were diagnosed after birth in the Stuttgart laboratory. Information on clinical and serological data obtained during prenatal care and at birth had been provided by the treating gynaecologists and paediatricians. Furthermore, serum samples from 11 of the 14 mothers were investigated at the Stuttgart laboratory after birth and also retrospectively at the Herford laboratory.
Results: All mothers presented without clinical signs of syphilis. Delayed prenatal care was observed in 6 out of 14 cases. Eleven of the 14 mothers had a positive treponemal screening test. Treatment was initiated only in two of them. During pregnancy treponemal IgM and cardiolipin antibodies were detected in none of 9 and in 5 of 8 sera of untreated mothers, respectively. In contrast, maternal serum samples investigated after birth were all positive for cardiolipin antibodies and 7 of 10 serum samples were positive for TP IgM antibodies.
Conclusions: Delayed or absent prenatal care and misinterpretation of syphilis serology (or laboratory failures) in the presence of latent syphilis are mostly responsible for the inadequate management of syphilis during pregnancy and thus the occurrence of CS.