title: Serum relaxin levels and kidney function in late pregnancy with or without preeclampsia.
abstract: OBJECTIVE
  Relaxin, a potent pregnancy-related hormone, has been proposed to be a major mediator of renal physiology in normal pregnancy. We wished to test relaxin levels in pregnancy and preeclampsia.
  
  
  METHODS
  We performed precise physiologic measurements of kidney function in 38 normal peripartum women and 58 women with preeclampsia. We measured serum relaxin levels prior to delivery and over the first 4 postpartum weeks utilizing a modern, validated ELISA. Results were compared to those of 18 normal women of childbearing age.
  
  
  RESULTS
  Relaxin levels were substantially elevated in women prior to delivery (364 ± 268 vs. 15 ± 16 pg/ml) and fell rapidly over the first postpartum week reaching normal non pregnant levels by Week 2 (32 ± 64 vs. 15 ± 16 pg/ml). No differences were seen between relaxin levels in normal pregnancy as compared to preeclampsia (364 ± 268 vs. 376 ± 241 pg/ml) despite substantial and persistent abnormalities in GFR (149 ± 33 vs. 89 ± 25 ml/min), albuminuria (14 vs. 687 mg/g) and mean arterial pressure (80 ± 8 vs. 111 ± 18). Furthermore no correlation could be established between physiologic measures (GFR, MAP, RBF, RVR) and relaxin levels (p > 0.3), either in the overall population or any of the subgroups.
  
  
  CONCLUSIONS
  Relaxin is indeed significantly elevated in the serum of women during late pregnancy and the early puerperium. However, serum relaxin does not appear to influence BP, renal vascular resistance, renal blood flow or GFR in late pregnancy or in women with preeclampsia.
authors.affiliation: Stanford University Medical Center, Stanford, CA 94305, USA. czar@stanford.edu
authors.forename: R A
authors.initials: RA
authors.lastname: Lafayette
authors.forename: M A
authors.initials: MA
authors.lastname: Hladunewich
authors.forename: G
authors.initials: G
authors.lastname: Derby
authors.forename: K
authors.initials: K
authors.lastname: Blouch
authors.forename: M L
authors.initials: ML
authors.lastname: Druzin
authors.forename: B D
authors.initials: BD
authors.lastname: Myers
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000097:blood; D001794:Blood Pressure; D002140:California; D016022:Case-Control Studies; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D007668:Kidney / Q000098:blood supply / Q000503:physiopathology*; D049590:Postpartum Period; D011225:Pre-Eclampsia / Q000097:blood* / Q000503:physiopathology*; D011247:Pregnancy; D011263:Pregnancy Trimester, Third; D012065:Relaxin / Q000097:blood*; D012079:Renal Circulation; D013997:Time Factors; D015854:Up-Regulation; D014655:Vascular Resistance; D055815:Young Adult
chemical_list: D015415:Biomarkers; D012065:Relaxin