A novel parameter derived from photoplethysmographic pulse wave to distinguish preeclampsia from non-preeclampsia

•A novel parameter named CHAR was first proposed.•CHAR was derived from the photoplethysmographic pulse wave noninvasively.•CHAR was suggested an effective tool in distinguishing patients with PE from those without PE. To describe the comparative hierarchical area ratio (CHAR), a novel parameter derived from the photoplethysmographic (PPG) pulse wave and differences in CHAR values in parturients with and without preeclampsia (PE). A total of 59 parturients (37 without and 22 with PE) was conducted at the Women’s Hospital, Zhejiang University, School of Medicine in Hangzhou, China. We calculated the CHAR values derived from the PPG pulse wave and compared them in parturients with and without PE. The values of CHAR derived from the parturients with PE were lower compared to those without PE (p