Preeclampsia Risk Assessment (sFlt-1/PlGF Ratio)

What is the role of the sFlt-1/PlGF ratio in preeclampsia?

Preeclampsia (PE) is a complication of pregnancy that affects approximately 5% of women worldwide.

Preeclampsia (PE)

Preeclampsia is a serious hypertensive condition occurring at mid-pregnancy.  Clinical signs of PE, such as the onset of hypertension, are typically observed after 20 weeks of gestation.  Clinically, PE may vary from mild to severe forms, and may require premature delivery.

Early-onset PE (EOP) develops before 34 weeks of gestation.  Late-onset PE (LOP), develops at 34 weeks of gestation or later.  LOP accounts for about 80 – 95% of all PE cases worldwide and is associated with a high prevalence of eclampsia and HELLP syndrome, both life-threatening complications.  EOP are less common.  It is associated with higher rates of neonatal mortality and maternal morbidity.  EOP and LOP have different implications for both the mother and the baby.

sFlt-1 and PlGF

Although the cause of PE remains unclear, the syndrome may be initiated by an imbalance of placental factors that induce endothelial dysfunction.  Soluble fms-like tyrosine kinase 1 (sFlt-1) and placental growth factor (PIGF) are both associated with placental dysfunction and the risk of PE during pregnancy.

Studies show that in both early and late onset PE, maternal serum levels of sFlt-1 are higher and PlGF lower in women presenting with PE compared to those with uncomplicated pregnancies.

The use of the sFlt-1/PIGF ratio is a useful tool to aid in risk assessment for the development of PE in pregnancy.  It also aids in the prognosis of adverse outcomes and assists with clinical management.  E.g. intensify close monitoring and decide the best delivery timing.  The sFlt-1/PlGF ratio results should be used in conjunction with information available from clinical evaluations and other standard of care procedures.