Maternal serum granulocyte-colony stimulating factor in preterm birth with subclinical chorioamnionitis

Preterm birth has been linked with intrauterine infection and inflammation. Serum and amniotic fluid markers of inflammation, such as interleukin-1 (IL-1), IL-6, and granulocyte-colony stimulating factor (G-CSF), have been associated with clinical chorioamnionitis and preterm delivery. As G-CSF regulates the production and maturation of neutrophils, we sought to determine if maternal serum G-CSF levels are elevated in patients with preterm birth with subclinical histologic chorioamnionitis. Maternal serum G-CSF levels were significantly different among five groups of women studied (P < .001, Kruskall-Wallis test), and were highest in subjects with preterm labor who delivered preterm (P < .05, Mann-Whitney U test). Among women with preterm labor who delivered preterm, maternal serum G-CSF levels were significantly higher if histologic chorioamnionitis was present than when histologic evidence of infection was not present (P = 0.04, Mann-Whitney U test). Intrauterine infection may cause a local inflammatory process and initiate preterm labor. This inflammatory response may include production of G-CSF, which would enter the circulation and stimulate the migration of neutrophils to the site of infection. Our data support this concept, as maternal serum G-CSF is elevated with subclinical infection in association with preterm birth.