Serum levels of macrophage colony-stimulating factor after cesarean section, vaginal delivery, or laparotomy in normal pregnant women and gynecologic patients.

Background: Macrophage colony-stimulating factor (M-CSF) is located in villous cells lining the vessels in the placenta in the third trimester and has been implicated in placental growth and development. Macrophage colony-stimulating factor levels in peripheral blood increased significantly with progression of pregnancy in uncomplicated pregnancies. The serum levels of M-CSF appear to be altered after laparotomy in normal pregnant women and nonpregnant gynecologic patients. Thus, the present study examined changes in serum levels of M-CSF before and after laparotomy and compared these findings between the two groups. Macrophage colony-stimulating factor levels before and after vaginal delivery were also examined.

Methods: Peripheral blood was collected before, 1 day, and 10 days after laparotomy or vaginal delivery from 38 subjects, of whom 14 were normal pregnant women who underwent cesarean section (group 1), 12 were gynecologic patients (group 2), and 12 were normal pregnant women who delivered vaginally (group 3). The M-CSF level was determined by the sandwich ELISA method using three antibodies.

Results: In all groups, the serum levels of M-CSF increased significantly 1 day after laparotomy or vaginal delivery, but then decreased significantly after 10 days. The net increase 1 day after laparotomy was significantly lower in group 1 than in group 2. Before and 1 day after laparotomy, the M-CSF levels were significantly higher in group 1 than in group 2, but not 10 days after laparotomy. Changes in M-CSF levels in group 3 were relatively similar to those in group 1.

Conclusions: Serum levels of M-CSF were significantly higher in groups 1 and 3 than in group 2, before laparotomy or vaginal delivery. The M-CSF level increased moderately 1 day after cesarean or vaginal delivery, and it increased remarkably after gynecologic laparotomy. The increases in M-CSF levels postlaparotomy may occur via different mechanisms between groups 1 and 2. Placental removal and termination of pregnancy might contribute to the decrease in M-CSF levels, leading to only a moderate increase in M-CSF levels 1 day after laparotomy in group 1.