PGF and preeclampsia: Alongside placental growth, soluble fms-like tyrosine kinase-1 (sFlt-1) rises too; an adaptive response to rising PlGF towards and during mid-gestation is an increasing level of sFlt-1 compared to weakly increasing PlGF, which indicates an anti-angiogenic state and is often pre-clinical evidence of other placental biomarkers relating to other pregnancy complications like preeclampsia and also have been shown to demonstrate placental insufficiency.