title: Renal handling of homocysteine during normal pregnancy and preeclampsia.
abstract: OBJECTIVE
  Maternal plasma homocysteine decreases in normal pregnancy and is significantly increased in preeclampsia. The goal of this study was to investigate the role of the maternal kidney in the changes of plasma homocysteine during normal pregnancy and preeclampsia.
  
  
  METHODS
  Plasma and 24-hour urine samples were collected in the same women before, during (first, second, and third trimesters), and after normal pregnancy; and in a separate cross-sectional study of normal pregnant, preeclamptic and nonpregnant women and homocysteine concentrations were measured.
  
  
  RESULTS
  Longitudinally, maternal plasma homocysteine decreased significantly by the first trimester compared with prepregnancy and postpartum levels (5.6 +/- 1.8 versus 6.8 +/- 0.5 and 7.4 +/- 0.4 microM, respectively, P<.05 by analysis of variance) and paralleled a significant increase in the renal clearance of homocysteine (2.9 +/- 0.4 versus 1.8 +/- 0.2 and 1.6 +/- 0.2 L/24 hours, respectively, P<.001). In addition, plasma homocysteine was significantly elevated in preeclampsia compared with normal pregnancy (4.4 +/- 0.6 versus 3.2 +/- 0.2 microM, P<.04); however, renal clearance was not different (1.2 +/- 0.1 versus 1.0 +/- 0.1 L/24 hours, P=.55).
  
  
  CONCLUSIONS
  Increases in renal clearance contribute to the decrease in plasma homocysteine during normal pregnancy. However, changes in renal handling do not appear to contribute to the increase in plasma homocysteine in preeclampsia.
authors.affiliation: Magee-Womens Research Institute and Department of Obstetrics, Gynecology and Reproductive Sciences, University of Pittsburgh, School of Medicine, Pittsburgh, Pennsylvania 15213, USA. rsirwp@mail.magee.edu
authors.forename: Robert W
authors.initials: RW
authors.lastname: Powers
authors.forename: Alana K
authors.initials: AK
authors.lastname: Majors
authors.forename: Laurie J
authors.initials: LJ
authors.lastname: Kerchner
authors.forename: Kirk P
authors.initials: KP
authors.lastname: Conrad
mesh_terms: D003430:Cross-Sectional Studies; D005260:Female; D005865:Gestational Age; D005919:Glomerular Filtration Rate; D006710:Homocysteine / Q000097:blood* / Q000652:urine; D006801:Humans; D007668:Kidney / Q000378:metabolism*; D008137:Longitudinal Studies; D008657:Metabolic Clearance Rate; D011225:Pre-Eclampsia / Q000097:blood* / Q000652:urine; D011247:Pregnancy
chemical_list: D006710:Homocysteine