Macrophage colony-stimulating factor levels in amniotic fluid before and after the onset of labor do not differ in normal pregnancies.

PROBLEM: Macrophage colony-stimulating factor (M-CSF) promotes placental growth and maintenance. M-CSF also regulates trophoblast invasion into the placental bed. We evaluated whether M-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 48 Japanese women experiencing normal pregnancies with single fetuses who had no infection. Of these pregnancies, 24 were women during labor: 22 led to subsequent term delivery (labors); two had premature delivery. The other 24 were women without labor underwent cesarean section (controls). These two groups (22 labors and 24 controls) were compared. The average gestational age at entry was 38 weeks of gestation. The women's ages and gestational ages did not differ significantly between the two groups. Amniotic fluid was collected and the M-CSF levels were compared between two groups. The M-CSF level was determined by the sandwich enzyme-linked immunosorbent assay (ELISA) method. RESULTS: The levels of M-CSF in amniotic fluid did not differ significantly between the women during labor and those without labor. CONCLUSIONS: M-CSF in amniotic fluid may not contribute to the onset of labor in term pregnancy and/or labor resulting in subsequent delivery may not induce the production and secretion of M-CSF into amniotic cavity.