Correlation of sFlt/PlGF ratio with severity of preeclampsia in an Indian population

Abstract

Preeclampsia affects 2% to 8% of pregnant women and significantly increases the risk for maternal and perinatal morbidity, especially in low- and middle-income countries. There is increasing evidence to support the use of biochemical markers such as placental growth factor and soluble fms-like tyrosine kinase-1 in predicting the severity of preeclampsia and to rule out severe disease in clinical conditions masquerading as severe preeclampsia. This study aimed to assess the role of the sFlt-1/PlGF ratio in predicting adverse perinatal and maternal outcomes in women with preeclampsia in a South Asian population with a higher rate of the disease and its associated complications. This was a prospective cohort study of women diagnosed with preeclampsia or suspected to have preeclampsia who underwent biophysical and biochemical investigations to measure the severity, including determining maternal hemodynamic indices, mean arterial pressure, fetal biometric and Doppler parameters, and soluble fms-like tyrosine kinase-1 and placental growth factor levels. The performance of these markers, individually or in combination, in predicting adverse perinatal and maternal outcomes was then assessed using receiver operating characteristic curve analysis. An adverse maternal outcome was defined as 1 or more of severe hypertension; admission to the intensive care unit; eclampsia; placental abruption; hemolysis, elevated liver enzymes, low-platelet count syndrome; disseminated intravascular coagulation; platelets <100×109/L; creatinine >1.1 mg/dL; and alanine aminotransferase >100 U/L. An adverse perinatal outcome was defined as 1 or more of preterm birth ≤34+0 weeks' gestation, neonatal intensive care unit admission for >48 hours, respiratory distress syndrome, intraventricular hemorrhage, hypoxic ischemic encephalopathy, necrotizing enterocolitis, retinopathy of prematurity, and confirmed fetal infection. We recruited 91 women with preeclampsia with a mean gestational age of 30.63±2.86 weeks. Women who had adverse maternal events had higher median maternal concentrations of soluble fms-like tyrosine kinase (11,500.0 pg/mL vs 3051.0 pg/mL; P<.001), lower concentrations of placental growth factor (44.88 pg/mL vs 148.50 pg/mL; P<.001), and a higher sFlt-1/PlGF ratio (306.22 vs 30.63; P<.001) than women who did not. Pregnancies with an adverse perinatal outcome also had a higher soluble fms-like tyrosine kinase concentration (12,100.0 pg/mL vs 3051.0 pg/mL; P<.001), lower placental growth factor concentration (27.2 pg/mL vs 148.50 pg/mL; P<.001), and higher sFlt-1/PlGF ratio (378.45.4 vs 30.63; P<.001). The area under the receiver operating characteristic curve showed that soluble fms-like tyrosine kinase and placental growth factor were the best biomarkers when compared with other biochemical markers to predict adverse maternal (area under the curve, 0.81; 95% confidence interval, 0.72-0.90) and fetal (area under the curve, 0.88; 95% confidence interval, 0.80-0.96) outcomes in preeclampsia. The sFlt-1/PlGF ratio correlates better with adverse maternal and perinatal outcomes than any other biochemical marker in an Indian population. The incorporation of the sFlt-1/PlGF ratio in women with preeclampsia can help in predicting the severity of the condition and the timings of the delivery.