title: Maternal 27-hydroxycholesterol concentrations during the course of pregnancy and in pregnancy pathologies.
abstract: The oxysterol 27-hydroxycholesterol (27-OHC) plays an important role in the regulation of cholesterol homeostasis. Pregnancy pathologies like preeclampsia (PE), HELLP-syndrome (HELLP), intrauterine growth restriction (IUGR) and intrahepatic cholestasis in pregnancy (ICP) are linked to disturbances in lipid metabolism. In the present study, we hypothesized a specific gestational regulation of 27-OHC and compromised 27-OHC levels due to placental and hepatic diseases in pregnancy resulting in a dysregulation of lipid metabolism.
  
  
  
  The 27-OHC was measured by gas-chromatography-mass spectrometry (GC-MS) and related to cholesterol concentrations. In the longitudinal cohort, a complete set of samples of healthy patients (n = 33) obtained at three different time points throughout gestation and once post-partum was analyzed. In the cross sectional cohort, patients with pregnancy pathologies (IUGR n = 14, PE n = 14, HELLP n = 7, ICP n = 7) were matched to a control group (CTRL) of equal gestational ages.
  
  
  
  The 27-OHC levels already increased in the first trimester despite lower TC concentrations (p < 0.05). During the course of pregnancy, a subtle rise in 27-OHC concentrations results in an overall decrease of 27-OHC/TC ratio in between the first (p < 0.05) and second trimester. The ratio remains stable thereafter including the post-partum period. No significant differences have been observed in pregnancy pathologies as compared to the CTRL group.
  
  
  
  In conclusion, 27-OHC may have a compensatory role in cholesterol metabolism early in pregnancy. The conserved 27-OHC/TC ratio in pregnancy pathologies suggest that neither the placenta nor the liver is majorly involved in the regulation of 27-OHC metabolism.
authors.affiliation: Department of Obstetrics and Gynecology, University Hospital of RWTH Aachen, Pauwelsstraße 30, 52074, Aachen, Germany. bwinkler@ukaachen.de.
authors.forename: Brigitte Sophia
authors.initials: BS
authors.lastname: Winkler
authors.affiliation: Department of Obstetrics and Gynecology, University Hospital of RWTH Aachen, Pauwelsstraße 30, 52074, Aachen, Germany.|Department of Obstetrics and Gynecology, University Hospital of Schleswig-Holstein, Michaelisstraße 16, 24105, Kiel, Germany.
authors.forename: Ulrich
authors.initials: U
authors.lastname: Pecks
authors.affiliation: Department of Obstetrics and Gynecology, University Hospital of RWTH Aachen, Pauwelsstraße 30, 52074, Aachen, Germany.
authors.forename: Laila
authors.initials: L
authors.lastname: Najjari
authors.affiliation: Department of Obstetrics and Gynecology, University Hospital of RWTH Aachen, Pauwelsstraße 30, 52074, Aachen, Germany.
authors.forename: Nicola
authors.initials: N
authors.lastname: Kleine-Eggebrecht
authors.affiliation: Department of Obstetrics and Gynecology, University Hospital of RWTH Aachen, Pauwelsstraße 30, 52074, Aachen, Germany.|Department of Obstetrics and Gynecology, University Hospital of Schleswig-Holstein, Michaelisstraße 16, 24105, Kiel, Germany.
authors.forename: Nicolai
authors.initials: N
authors.lastname: Maass
authors.affiliation: Department of Nephrology, Hypertension and Clinical Pharmacology, Inselspital, Department of Clinical Research, University of Bern, Freiburgstrasse, 3010, Berne, Switzerland.
authors.forename: Markus
authors.initials: M
authors.lastname: Mohaupt
authors.affiliation: Department of Nephrology, Hypertension and Clinical Pharmacology, Inselspital, Department of Clinical Research, University of Bern, Freiburgstrasse, 3010, Berne, Switzerland.
authors.forename: Geneviève
authors.initials: G
authors.lastname: Escher
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000097:blood; D003430:Cross-Sectional Studies; D005260:Female; D005500:Follow-Up Studies; D008401:Gas Chromatography-Mass Spectrometry; D005865:Gestational Age; D006801:Humans; D006888:Hydroxycholesterols / Q000097:blood*; D008875:Middle Aged; D010920:Placenta / Q000473:pathology*; D049590:Postpartum Period / Q000097:blood*; D011247:Pregnancy; D011248:Pregnancy Complications / Q000097:blood* / Q000175:diagnosis; D011256:Pregnancy Outcome; D011261:Pregnancy Trimester, First / Q000097:blood; D011262:Pregnancy Trimester, Second / Q000097:blood; D055815:Young Adult
chemical_list: D015415:Biomarkers; D006888:Hydroxycholesterols; C076996:27-hydroxycholesterol
keywords: 27-OHC/TC ratio; 27-hydroxycholesterol; HELLP-syndrome; Intrahepatic cholestasis in pregnancy; Intrauterine growth restriction; Lipid metabolism; Preeclampsia