Granulocyte-macrophage colony-stimulating factor levels in amniotic fluid before the onset of labor and during labor do not differ in normal pregnancies

Problem. Granulocyte-macrophage colony-stimulating factor (GM-CSF) at the implantation site may regulate invasion and differentiation of placental trophoblast. We evaluated whether GM-CSF levels in amniotic fluid during labor contributing to subsequent delivery differed from those before the onset of labor in normal pregnancies. Method of Study. This study enrolled 36 Japanese women experiencing normal pregnancies with single fetuses who had no infection. Of these pregnancies, 18 were women during labor that led to subsequent term delivery (labors). The other 18 were women without labor underwent cesarean section (controls). These two groups (18 labors and 18 controls) were compared. The average gestational age at entry was 38-39 weeks of gestation. The women's ages and gestational ages did not differ significantly between the two groups. Amniotic fluid was collected and the GM-CSF levels were compared between two groups. The GM-CSF level was determined by the enzyme-linked immunosorbent assay method. Results. There was no significant increase in GM-CSF levels in amniotic fluid during labor compared with that before the onset of labor. Conclusions. The GM-CSF in amniotic fluid may not promote the onset of labor at term and/or term labor contributing to subsequent delivery may not induce the production and secretion of GM-CSF into amniotic cavity.