Pre-eclampsia is associated with marked alterations in sleep architecture

Study Objectives: Pre-eclampsia is currently the predominant cause of mater nal and fetal morbidity and mortality. Diurnal blood pressure variation is flattened or reversed in pre-eclampsia; however, sleep has not been extensi vely investigated in this disease. Our objective was therefore to study sle ep architecture in this group of patients. Study Design: Full polysomnography using the Compumedics Sleepwatch System( R) or Compumedics p-series. Setting: NA Patients: 25 pre-eclamptic patients and 17 primigravidas with normal pregna ncies and no history of cardiovascular disease or sleep disorder. With the exception of one subject, all pre-eclamptics were taking clonidine (a known suppressant of rapid eye movement-REM-sleep) for control of their hyperten sion. Interventions: NA Results: Pre-eclamptic subjects had markedly altered sleep architecture, wi th a markedly increased percentage of time spent in slow-wave sleep (SWS) ( 21 * 2% versus 43 * 3%, p < 0.001). There was a longer latency to rapid eye movement (REM) sleep (92 * 11 mins vs. 205 * 23 mins in control and pre-ec lamptic subjects, respectively, p < 0.001) and reduced time spent in REM (1 8 * 1% and 10 * 2% in control and pre-eclamptic subjects, respectively, p < 0.001). Conclusions: While the increased REM latency and decreased REM time are mos t likely due to clonidine, this is unlikely to also account for the increas ed SWS. Two possible explanations for this include cerebral edema and relea se of cytokines, which are known to alter sleep structure.