Chlamydia trachomatis seropositivity is associated both with stillbirth and preterm delivery

The cause of stillbirth and preterm delivery is often unknown. We studied t he prevalence of Chlamydia trachomatis antibodies in mothers with stillbirt h and preterm labor. Serum specimens from 72 mothers with stillbirth after the 21st gestational week, and from 48 mothers with preterm delivery betwee n gestational weeks 23 and 29, both from the greater Helsinki area, and cor d blood from 96 consecutive liveborn deliveries at the Department of Obstet rics and Gynecology, the University of Helsinki, were studied for antibodie s to C. trachomatis immunotypes CJHI, GFK and BED by microimmunofluorescenc e test. The prevalence of C. trachomatis antibodies was highest, 33.3%, in mothers with stillbirth, 18.8% in mothers with preterm delivery, and 10.4% in cord blood. The IgM seropositivity rate was high among mothers with pret erm delivery (8.3%). We conclude that C. trachomatis IgG antibodies are fre quently detected in sera from mothers with stillbirth, suggesting past infe ction, while mothers with preterm delivery often have serum IgM antibodies, suggesting of acute infection.