Plasma granulocyte colony stimulating factor concentrations in pregnant women.

We measured the plasma granulocyte colony stimulating factor (G-CSF) concentrations in pregnant women to evaluate the association between G-CSF and increased neutrophil counts that has been observed during pregnancy. We examined 96 pregnant and 10 nonpregnant women. The G-CSF concentrations were assayed using a sandwich enzyme immunoassay. The G-CSF concentrations in pregnant women were significantly higher at all times than those of nonpregnant women. The G-CSF concentrations were also significantly higher during than before labor. The plasma G-CSF concentrations were positively correlated with the neutrophil counts during the 3rd trimester only. In conclusion, increased G-CSF concentrations may be related to the increases in neutrophil counts in pregnant women, especially during the 3rd trimester.