Pneumococcal polysaccharide antibody levels in patients with term and preterm pregnancies.

Serum antibody levels against 12 serotypes of pneumococcal polysaccharide were assessed in pregnant women as well as in cord bloods of their infants. Twelve women were evaluated during the first trimester, second trimester, and in labor at term, and eight women were assessed in the first trimester and in preterm labor. Antibody levels significantly decreased from the first trimester to delivery both in patients with term (339 versus 281 ng AbN/mL; P less than .001), and preterm (448 versus 299 ng AbN/mL; P less than .001) deliveries. There was no significant difference in mean antibody levels or their rate of decline between term and preterm pregnancies.