Placental Growth Factor (PlGF) (Preeclampsia)

General Information

Placental growth factor (PlGF) is an important component of the clinical management of preeclampsia. It is vascular endothelial growth factor, a protein that is mainly produced in the placenta, but is also produced in low concentrations in other tissues: heart, lungs, thyroid, liver, skeletal muscles and bones. The human placental growth factor gene is located on the short arm of chromosome 14 and encodes 4 isoforms of the protein. plGF1 and PlGF2 are secreted in greatest amounts during pregnancy.

Placental growth factor and angiogenesis

Angiogenesis – the formation of new blood vessels, is a vital process during embryogenesis (fetal development) and is regulated by a number of growth factors. New blood vessels are formed by remodeling (transformation) of the existing vasculature - through branching, extension and expansion.

In adults, angiogenesis occurs in the endometrium - during the menstrual cycle, during wound healing, during the adaptive processes of the heart and skeletal muscles, and more. Placental growth factor is a pro-angiogenic factor that stimulates angiogenesis. Under the influence of placental growth factor, angiogenesis in trophoblast cells (placenta) takes place in a non-ischemic environment, while in other tissues it is activated in response to ischemia and other pathological processes. Placental growth factor production in tumor cells leads to tumor vascularization.

Placental growth factor and Physiological pregnancy

The concentration of placental growth factor in the first trimester is low, it starts to increase from 11-12 weeks. It reaches its peak by 30 weeks, after which the tendency to decrease again is observed.

Placental growth factor in preeclampsia

A decrease in the concentration of placental growth factor in urine and blood serum is observed both in preeclampsia and in the full development of the clinical picture of the disease. PlGF deficiency is caused by decreased expression of placental growth factor and its sequestration by endovascular growth factor protein sFLT-1.

sFLT-1 represents the extracellular domains of vascular endothelial growth factor receptor-1. sFLT-1 increases in preeclampsia).

Predicting preeclampsia by isolated assessment of angiogenic factors (placental, endovascular) is less efficient, compared to the assessment of the ratio of these factors.

The ratio of sFLT-1/PlGF angiogenic factors, together with the patient's anamnesis and ultrasound data, provides the possibility of predicting preeclampsia.

When preeclampsia is suspected, evaluation of the sFLT-1/PlGF ratio or plasma placental growth factor (PlGF) alone are essential tests to confirm or rule out the diagnostics. Plasma PlGF assessment predicts preeclampsia significantly better than clinical 5-factor assessment (estimation of systolic and diastolic blood pressure, alanine transferase, uric acid and proteinuria).

Material for examination:  Venous blood

Preliminary preparation:  it is not necessary.

The test is performed at 20-35 weeks of pregnancy, in the presence of pre-eclampsia symptoms.