sFlt-1 Blood Test and sFlt-1/PlGF Ratio Explained
The sFlt-1 blood test measures a placental protein used in the sFlt-1/PlGF ratio test to predict preeclampsia risk. A normal sFlt-1/PlGF ratio is typically below 38. High levels indicate placental stress and increased risk of preeclampsia. This test helps detect complications before symptoms appear and guides pregnancy management.
Contents
Result interpretation sFlt-1
What your result means based on common reference ranges
sFlt-1 levels within ratio below 38 indicate low short-term risk of preeclampsia and normal placental function.
Moderately elevated sFlt-1/PlGF ratio suggests increased preeclampsia risk and requires closer monitoring of blood pressure and fetal growth.
High sFlt-1 levels with ratio above 85 or 110 indicate severe placental dysfunction and high risk of preeclampsia complications.
Low sFlt-1 levels with high PlGF reflect healthy placental circulation and low likelihood of hypertensive pregnancy disorders.
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What is sFlt-1?
sFlt-1 is a circulating protein that binds vascular growth factors and disrupts normal blood vessel function when elevated. In pregnancy, its level is assessed through the sFlt-1/PlGF ratio blood test, a key tool for predicting preeclampsia and placental dysfunction. High sFlt-1 levels reduce angiogenesis, leading to hypertension, endothelial damage, and impaired placental perfusion. This biomarker is widely used in obstetrics to evaluate short-term risk, especially in combination with PlGF, blood pressure, and proteinuria.
Reference ranges
Causes of abnormal values
Causes of low sFlt-1
- • Healthy pregnancy — balanced angiogenic signaling maintains low sFlt-1
- • Early gestation — naturally low production before placental maturation
- • Good cardiovascular health — efficient blood flow reduces placental stress signals
Causes of high sFlt-1
- • Preeclampsia — excessive placental production damages vascular balance
- • Gestational hypertension — early endothelial stress increases sFlt-1 release
- • Multiple pregnancy — larger placental mass increases protein output
- • Placental insufficiency — hypoxia triggers anti-angiogenic factors
- • Chronic hypertension — vascular stress elevates sFlt-1 production
- • Kidney disease — reduced clearance raises circulating sFlt-1
sFlt-1 in combination with other markers
Possible symptoms
- •Persistent headaches
- •Visual disturbances
- •Sudden swelling (edema)
- •Upper abdominal pain
- •Nausea or vomiting in later pregnancy
When to see a doctor
Seek medical attention if the sFlt-1/PlGF ratio exceeds 38 and blood pressure rises or symptoms develop. Immediate evaluation is needed if severe headache, vision changes, or rapid swelling occur. Regular monitoring is essential when results trend upward.
What to do if abnormal
- Monitor blood pressure daily
- Attend all prenatal appointments
- Maintain hydration and rest
- Learn warning signs of preeclampsia
- Follow medical advice on delivery timing
The information on this page is intended for general understanding of test results and does not replace medical consultation. Accurate interpretation requires considering other blood markers and individual factors.
Content is based on medical literature and used within the PulseBook analytical system.
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