Soluble fms-like tyrosine kinase-1 (sFlt-1) and placental growth factor (PlGF) are angiogenic biomarkers used in predicting pre-eclampsia. The sFlt-1/PlGF ratio that best predicts short-term absence of pre-eclampsia within one week (rule-out) is:
- A Ratio >85
- B Ratio >110
- C Ratio ≤38 ✓
- D Ratio <20
Correct answer: C. Ratio ≤38
Explanation
An sFlt-1/PlGF ratio ≤38 has a high negative predictive value (99.3%) for ruling out pre-eclampsia within the next week, as shown by the PROGNOSIS trial. A ratio >38 increases pre-eclampsia risk, while >85 is used in some centers to predict development within 4 weeks. The biomarker ratio reflects the anti-angiogenic state in pre-eclampsia, where sFlt-1 (which sequesters VEGF and PlGF) is elevated and free PlGF is reduced. This ratio is increasingly incorporated into guidelines for outpatient management decisions.
Reference: Williams Obstetrics, 26th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.