Background: New-onset hypertension in pregnancy is a significant cause of maternal and fetal morbidity and mortality worldwide. Early prediction of disease severity is crucial for timely intervention. Glycosylated fibronectin has emerged as a potential biomarker for predicting the severity of hypertensive disorders in pregnancy. Methods: This cross-sectional study included 60 pregnant women diagnosed with new-onset hypertension. Serum levels of glycosylated fibronectin were measured and correlated with the severity of hypertension and clinical outcomes. Statistical analysis was performed using appropriate tests, and p-values < 0.05 were considered significant. Results: Elevated levels of glycosylated fibronectin were significantly associated with severe hypertension (p < 0.001). Patients with higher glycosylated fibronectin levels had an increased incidence of adverse maternal and fetal outcomes. Glycosylated fibronectin demonstrated good predictive value for disease severity with an area under the ROC curve of 0.85. Conclusion: Glycosylated fibronectin estimation is an effective biomarker for predicting the severity of new-onset hypertension in pregnancy, aiding in early identification and management of high-risk patients.