Background & Objective: Preeclampsia is a multisystem disorder and one of the principal causes of illness and death among mothers, fetuses, and newborns, characterized by hypertension and proteinuria. Placental growth factor (PlGF) promotes angiogenesis, whereas soluble fms-like tyrosine kinase-1 (sFlt-1), secreted primarily by the placenta, antagonizes both PlGF and vascular endothelial growth factor (VEGF), thereby contributing to endothelial dysfunction. This study aimed to evaluate maternal serum levels of PlGF and sFlt-1, and the ratio between them, in women with preeclampsia compared with normotensive pregnant controls.
 Materials & Methods: This case–control study enrolled 125 pregnant women: 75 with preeclampsia and 50 normotensive controls, recruited between July 2024 and May 2025 at Bint Al-Huda Teaching Hospital and Al-Haboubi Teaching Hospital in Nasiriyah, Iraq. Blood pressure was assessed with a standard mercury sphygmomanometer. Venous blood samples were collected, processed, and stored at −20°C. Exclusion criteria included chronic hypertension, diabetes mellitus, renal disease, coagulation disorders, urinary tract infections, autoimmune diseases, or lack of informed consent.
Results:  Serum PlGF concentrations were markedly reduced in the preeclampsia group (mean [SD], 5.18 [1.82]) compared with controls (14.38 [20.47]). Conversely, sFlt-1 levels were significantly elevated among women with preeclampsia (6.84 [1.60]) than in controls (3.74 [3.04]). The sFlt-1/PlGF ratio was markedly elevated in participants with preeclampsia (1.28 [0.51]) compared with controls (0.42 [0.42]).
Conclusion:  Maternal obesity and advanced gestational age increase the risk of preeclampsia. Assessment of sFlt-1, PlGF, and the sFlt-1/PlGF ratio measured during the third trimester may serve as valuable diagnostic biomarkers for preeclampsia and assist in developing targeted therapeutic strategies.