title: The circadian rhythm of blood pressure during pregnancy.
abstract: OBJECTIVE
  To review the literature on the circadian rhythm of blood pressure during pregnancy.
  
  
  METHODS
  Computerized searches on MEDLINE, CINAHL, and MIRLYN.
  
  
  METHODS
  Selected studies from 1 969 to 1997 were evaluated.
  
  
  METHODS
  Data were extracted and information was organized under the following areas: definition of and the interconnection between circadian rhythm and blood pressure; the circadian variability of blood pressure throughout the trimesters; the patterns of the circadian rhythm of blood pressure in pregnancies defined as normal and those complicated by chronic hypertension and preeclampsia; and clinical implications.
  
  
  RESULTS
  The circadian rhythm of blood pressure in pregnancy is the same as in the non-pregnant state, with a nocturnal decrease, especially during sleep. In patients with chronic hypertension, the nocturnal fall in blood pressure may be steeper. Patients with mild preeclampsia may experience a less pronounced nocturnal decrease in blood pressure. Patients with severe preeclampsia may display a reversed circadian rhythm, with no decrease and/or an increase in nocturnal blood pressure.
  
  
  CONCLUSIONS
  The patterns of the circadian rhythm of blood pressure during normal pregnancy and pregnancies complicated by chronic hypertension and preeclampsia warrant consideration when monitoring patients and implementing management plans.
authors.affiliation: Henry Ford Hospital, Labor & Delivery Unit, Detroit, MI 48202-2689, USA.
authors.forename: C D
authors.initials: CD
authors.lastname: Larry
authors.forename: S
authors.initials: S
authors.lastname: Yeo
mesh_terms: D001794:Blood Pressure / Q000502:physiology*; D001795:Blood Pressure Determination; D002940:Circadian Rhythm / Q000502:physiology*; D005260:Female; D006801:Humans; D011247:Pregnancy / Q000502:physiology*