To study the cognitive function status, serum phosphorylated tau181 (P-tau181) protein level, and total tau (T-tau) protein level in patients with preeclampsia (PE), pregnant healthy controls (PHCs), and non-pregnant healthy controls (NPHCs), and to research their feasibility as serum biomarkers for evaluating cognitive functional impairment in PE patients. This evidence concerns the gene MAPT and preeclampsia.