Predictive Value of Sflt-1/Plgf Ratio for Occurrence of Preeclampsia in Singleton Pregnancies: A Retrospective Study

Introduction: Preeclampsia is multisystem disorder of pregnancy, characterized by endothelial and placental dysfunction. It is classified as an early onset (which occurs < 34 weeks) and late onset (which occurs ≥ 34 weeks). There is an increase of level of antiangiogenic factor of soluble form similar to tyrosine kinase 1 (sFlt-1) and decrease of level of proangiogenic placental growth factor (PlGF) at preeclampsia. High ratio sFlt-1/PlGF is connected to occurrence of preeclampsia. Materials and Methods: There was a retrospective study of the Clinic for Gynecology and Obstetrics of the University Clinical Center of Republic of Srpska (KGA UKC RS), which was implemented in period January 1st, 2020 – December 31st, 2021 and which included 224 patients hospitalized at the Department of Perinatology for suspected preeclampsia development, from 26+0 weeks of gestation until birth. One of the key criteria for the inclusion of patients in the study is the use of the sFlt-1/PlGF ratio as a marker for the onset of preeclampsia, and the determination of protein values in 24-hour urine (biuret). The antenatal state of the fetus was also monitored by ultrasound measurement of the flow resistance ratio (Ri) through the middle cerebral artery and the umbilical artery (C/U), as well as the values of the newborn’s Apgar score in the first and fifth minute of life (AS 1 and 5). The patients included in the study were divided into two groups according to gestational age: group 1 (<33+6 NG) and group 2 (≥34NG). For the purposes of the research, data from patient protocol books for the specified period, as well as corresponding data from the Clinical Information System (KIS), were used. Results: Calculated values for cut off 38 for group 1 are: NPV= 76.9%, PPV=72.0%, sensitivity=85.7%, specificity=58.8%, and for group 2 are: NPV= 89 ,1%, PPV=40.8%, sensitivity=72.1%, specificity=68.5%. For cut off 85, the calculated values for group 1 are: NPV= 82.4%, PPV=85.7%, sensitivity=85.7%, specificity=82.4%, and for group 2 they are: NPV= 84.9 %, PPV=70.4%, sensitivity=44.2%, specificity=94.4%. For cutt off 110, the calculated values for group 1 are: NPV= 77.8%, PPV=85%, sensitivity=81%, specificity=82.4%, and for group 2 they are: NPV= 83.5 %, PPV=72.7%, sensitivity=37.2%, specificity=95.8%. The measured value of protein in 24h urine (biuret) in comparison with the measured values of the sFlt-1/PlGF ratio have statistical significance for predicting the onset of preeclampsia. Statistical data processing obtained by examining the measured values of the sFlt-1/PlGF ratio and the antenatal and natal condition of the fetus (C/U and AS 1 and 5) showed statistical significance, except for C/U for group 2, where p=0.32. Conclusion: Determination of the sFlt-1/PlGF ratio as well as biuret and monitoring of the antenatal and postnatal state of the fetus significantly contributes to the timely diagnostic of preeclampsia, which impacts reducing the incidence of undesirable outcomes for the mother and the fetus.