Maternal and congenital syphilis in Shanghai, China, 2002 to 2006

To assess the trends and determinants of maternal and congenital syphilis in Shanghai, China.

We conducted a prospective cohort study of maternal and congenital syphilis from 2002 to 2006 in Shanghai, China. We presented the trends of maternal syphilis and congenital syphilis rates and compared outcomes in infants born to mothers with complete versus incomplete treatment for maternal syphilis. We also assessed the determinants of compliance to treatment of maternal syphilis and examined the associations of initial maternal RPR antibody level and gestational age at initiation of treatment with occurrence of congenital syphilis.

A total of 535 537 pregnant women were included in the analysis. During this period of time, 1471 maternal syphilis cases (298.7 per 100 000 live births) and 334 congenital syphilis cases (62.4 per 100 000 live births) were identified. Both maternal and congenital syphilis rates increased from 2002 until 2005, with a slight decrease in 2006. The rate of maternal syphilis was 156.2 per 100 000 live births in Shanghai residents and 371.7 per 100 000 live births in the migrating population (p<0.001). The compliance to treatment for maternal syphilis was poorer in women with a lower level of education. The rate of congenital syphilis in infants born to mothers with incomplete treatment (50.8%) was much higher than in infants born to mothers with complete treatment (12.5%). Rates of fetal death, neonatal death, and major birth defects were 30.4%, 11.0%, and 3.8%, respectively, in the incomplete treatment group; the corresponding figures were 5.5%, 0.56%, and 0.46%, respectively, in the complete treatment group. Infant outcome was also affected by initial maternal RPR antibody level and time of treatment, with much better outcomes in mothers with low antibody levels and earlier treatment.

There has been a resurgence of congenital syphilis in Shanghai, China, especially in the migrating population and other populations with a lower socioeconomic status.