Evaluation of Soluble Fms-like Tyrosine Kinase-1 in First Trimester of Pregnancy: A Cross-sectional Study

Abstract

Introduction: Soluble fms-like tyrosine kinase-1 (sFLT-1) is the form of the Vascular Endothelial Growth Factor (VEGF) receptor-1. It is an anti-angiogenic protein tyrosine-kinase receptor that binds to the VEGF. In pregnancy, the overexpression of receptor in placenta inhibits the formation of new blood vessels in uterus, and has been implicated in abnormal embryonic and placental development, and other complications of pregnancy like preeclampsia. Aim: To determine the levels of soluble fms-like tyrosine kinase-1 (sFLT-1) in sera of apparently healthy pregnant women in the gestational age group of 4 to 10 weeks. Materials and Methods: A cross-sectional study conducted at Sri Ramachandra Medical College and Research Institute, Chennai, Tamil Nadu, India. Serum sFLT-1 levels of 140 pregnant women (in first trimester of their pregnancy) were measured by Enzyme-Linked Immuno Sorbent Assay (ELISA). Correlation of gestational age with sFLT-1 values was performed by using Karl Pearson’s correlation coefficient. Results: The mean value of sFLT-1 in pregnancy was found to be 1043±435 pg/mL. A significant positive correlation was observed between gestational age and sFLT-1 in early pregnancy. Linear regression equation for predicting the sFLT-1 level based on the gestational age=282.57+94.23* (gestational age in weeks). Conclusion: sFLT-1 levels were observed to be directly correlated to the gestational age, and increased with gestational age. Determining the level of sFLT-1 in early first trimester of pregnancy and establishing its reference interval based on gestational age can help in differentiating normal pregnancy from a non-viable pregnancy in the early stages.

Keywords

• angiogenesis
• gestational age
• reference range
• vascular endothelial growth factor receptor-1