Maternal Serum Levels of Macrophage Colony-Stimulating Factor Are Associated With Adverse Pregnancy Outcome

Macrophage colony-stimulating factor (M-CSF) is expressed in the chorionic villous stroma of the human placenta, and maternal serum levels during pregnancy are higher than in nonpregnant women. Studies in mice show that M-CSF stimulates receptor-bearing placental trophoblasts. The present study examined changes in serum M-CSF through pregnancy and possible correlations with pregnancy outcomes. In 206 nulliparous and 304 multiparous women, samples were obtained to estimate M-CSF by enzyme immunoassay at 13 to 17 weeks’ gestation, 24 to 27 weeks’ gestation, onset of labor, and 6 weeks postpartum. Some form of hypertension was present in 88 instances.Maternal serum levels of M-CSF increased 111 percent from the end of the fist trimester to the end of gestation in normal nulliparous pregnancies. Those with adverse outcomes, in contrast, had only a 36 percent increase. M-CSF levels increased 70 percent during the last two trimesters of multiparous pregnancies but only 4 percent in those with adverse outcomes, and levels declined 23 percent in women who developed preeclampsia. In the overall study population, M-CSF levels at 13 to 17 weeks’ gestation were higher in pregnancies ending in preterm delivery or a low-birthweight infant than in normal pregnancies. The change in levels from that point to labor/delivery was less in preeclamptic pregnancies than in all others. Both absolute levels of maternal serum M-CSF and relative changes during the course of pregnancy correlate with adverse pregnancy outcomes, especially preterm delivery and low birthweight.Eur J Obstet Gynecol Reprod Biol 2000;89:19–25