CHANGES IN MATERNAL PLASMA MACROPHAGE-COLONY-STIMULATING FACTOR LEVELS DURING NORMAL-PREGNANCY

An enzyme-like immunosorbent assay and a blood autoanalyser were used to determine macrophage-colony stimulating factor (M-CSF) levels and t he absolute number and percentage of circulating monocytes in 80 norma l women with singleton pregnancies at 12-40 weeks' gestation, and ten healthy non-pregnant volunteers. The mean values of M-CSF and absolute number and percentage of circulating monocytes of the control group w ere 367 U/ml (SD 43) and 389 x 10(6)/l (SD 180) and 5.3% (SD 1.7) resp ectively. In pregnancy, M-CSF was significantly higher than non-pregna nt controls only after 28 weeks' gestation. The absolute number and th e percentage of circulating monocytes increased significantly with ges tation after 16 weeks. There was no significant association between th e concentration of M-CSF and the number or percentage of circulating m onocytes. These data suggest that during pregnancy there is an up-regu lation of M-CSF and monocytes.