sFLt-1 - An Effective Preeclampsia Prediction Tool During Pregnancy

Pregnancy is a milestone journey in every parent’s life. However, despite the joyful atmosphere surrounding it, pre-labor jitters and fear of complications can dampen any pregnant mom’s spirits.

One such pregnancy complication that can adversely affect the baby and the mother is Preeclampsia.  In India, the incidence of Preeclampsia is reported to be 8-10% among pregnant women¹.

But before you panic, let us tell you more about the pregnancy-related blood pressure complication and preeclampsia prediction tools that can be helpful.

What Is Preeclampsia?

Preeclampsia is a pregnancy-related complication which is usually characterized by high blood pressure and proteinuria (high levels of protein in the urine) that indicates kidney or other organ damage. It often starts after 20 weeks of pregnancy among women with previous standard blood pressure levels².    

If not treated appropriately, it can lead to severe adverse or fatal outcomes to the baby and the mother.

Preeclampsia is normally treated with blood-pressure-lowering medications and careful monitoring of the condition to prevent complications before delivery².

Tools For Early Preeclampsia Prediction

Early preeclampsia prediction plays an important role in aiding effective management of this disorder³. And one of the most efficient ways to predict preeclampsia within a short term (after week 20 up to week <34^{+0 days}) is measuring the sFlt-1 and PlGF ratio⁴.

What Are sFlt-1 and PlGF?

Both - sFlt-1 and PlGF - are produced by the placenta⁵.

The term sFlt-1’s expanded form reads - soluble fms-Like Tyrosine Kinase-1. It is an anti-angiogenic factor. Anti-angiogenic factors are agents that reduce the growth of new blood vessels⁶. When the sFlt-1 binds with PlGF, its antiangiogenic factors neutralize the proangiogenic factors of PlGF⁵.

PlGF - or placental growth factor, is a proangiogenic agent that promotes growth of new blood vessels⁵. As pregnancy progresses, PlGF levels rise and peak around 26-30 weeks’ gestation. If the levels do not rise, this may indicate a problem with the placenta, which is associated with Preeclampsia. In Preeclampsia, levels of PlGF can be abnormally low⁷.

In women with Preeclampsia, several antiangiogenic factors like soluble FMS-like tyrosine kinase 1 (sFLT1) are produced in higher-than-normal quantities⁸. 

Therefore, increased sFlt-1 levels and decreased PlGF levels can be used as important biomarkers in the prediction of Preeclampsia before the actual clinical onset.

Short-Term Preeclampsia Prediction - How It Helps?

Short-term Preeclampsia Prediction is a system of investigation that can predict the risk of developing Preeclampsia between week 20 to week <34^{+0 days} weeks of gestation through Placental Growth Factor (PlGF) and soluble fms-like Tyrosine Kinase-1 (sFlt-1) markers.

In order to predict short-term Preeclampsia, the sFlt-1 and PlGF levels are measured in ratios. A cut-off value of the sFlt-1/PlGF-ratio below 38 in pregnant women with suspected Preeclampsia can accurately rule out the onset of the disease within one week⁹. 

This helps the clinician in charge to decide whether an immediate hospitalization is required. If necessary, further testing with this ratio is recommended, along with other lab studies.

Summary

Pregnancy is a milestone journey in every parent’s life. However, in situations where pregnancy complications like Preeclampsia are suspected, taking necessary diagnostic steps can help mitigate the problem. 

And Preeclampsia Prediction prenatal test taken during week 20 to week  <34^{+0 days} of pregnancy, can effectively help in ruling out the disorder before the clinical onset of symptoms. The results of the test can help doctors recommend the next course of action that involves intense monitoring of the condition and may include use of blood-pressure-lowering medications.

Early prediction of Preeclampsia plays a key role in ensuring a safe pregnancy outcome, both for the baby and the mother.