MIC-1: Macrophage inhibitory cytokine 1. MIC-1 is produced in the placenta. A divergent member of the transforming growth factor beta superfamily. There are detectable levels of MIC-1 in the blood of the mother during pregnancy. Low levels of MIC-1 in maternal serum are predictive for an elevated risk of early pregnancy loss. Also known as placental bone morphogenetic protein and placental BMP.