To search for additional criteria for the prenatal diagnosis of fetal infection, the serum concentration of acute-phase inflammation proteins, such as α2-macroglobulin (MG), pregnancy-associated α2-glycoprotein, α1-antitrypsin, lactoferrin (LF), and C-reactive protein (CRP), were studied in 32 patients with G serum antibodies to Chlamydia trachomatis and hydramnios at 38-40 weeks' gestation. A control group consisted of 17 healthy women with physiological pregnancy. The blood LF concentration of more than 4.2 mg/l in pregnant women at 38-40 weeks' gestation was ascertained to be a highly informative indicator of fetal infection. The elevated total levels of MG and CRP increase the probability of accurately predicting the infection in a fetus and a neonate.