Objective: Maternal serum levels of macrophage colony stimulating factor (M-CSF) were measured longitudinally throughout pregnancy and in the postpartum period. The relationship of serum M-CSF levels and pregnancy outcome was determined.Study Design: Serum samples were obtained at 13-17 weeks, 24-27 weeks, onset of labor, and 6 weeks post-partum. M-CSF levels were measured using commercial ELISA kits. Gestational hypertension (GH) was defined as systolic/diastolic blood pressure ≥ 14090 mmHg found at two occasions, and adverse pregnancy outcome was recorded if severe GH, preeclampsia (GH with proteinuria), preterm delivery (PT), or low birth weight (LBW) occurred.Results: Twenty-three percent of 196 nulliparous pregnancies developed GH, while only 10.7% of 269 multiparous pregnancies had GH. The incidence of preeclampsia was 2.6% in the nulliparous group and 1.5% in the multiparous women. At the end of gestation, maternal M-CSF levels were 26% lower in nulliparous pregnancies with adverse outcomes than in those with normal outcome. In contrast, late in the first trimester maternal M-CSF levels were 29% higher in multiparous pregnancies experiencing adverse outcomes (1563 ± 26 vs. 1213 ± 42 pg/ml, P < 0.05), but similar at the end of pregnancy. In the total population of 465 pregnancies, maternal M-CSF values at 13-17 weeks in pregnancies producing LBW infants (1535 ± 239 pg/ml) or PT delivery (1601 ± 261 pg/ml) were higher than those in normal pregnancies (1180 ± 31 pg/ml), P < 0.05.Conclusion: In this patient population, a deficiency of M-CSF occurred in nulliparous pregnancies with adverse outcomes, but in multiparous women destined to have adverse pregnancy outcomes, maternal M-CSF levels are elevated by the end of the first trimester. The difference between nulliparous and multiparous pregnancies requires further consideration.
