title: Apelin in Normal Pregnancy and Pregnancies Complicated by Placental Insufficiency.
abstract: Apelin is a potent inotropic agent and causes endothelium-mediated vasodilation. Its cardiovascular profile suggests a role in the regulation of gestational hemodynamics.
  
  
  
  We longitudinally assessed maternal serum apelin levels and hemodynamics (cardiac output and total peripheral resistance) between 20 and 34 weeks gestation in 18 women at high risk of placental dysfunction. Placental apelin staining was assessed by immunohistochemistry in placentas from uncomplicated pregnancies (n = 6), preterm deliveries (n = 6), preeclampsia (PET, n = 8), and isolated intrauterine growth restriction (IUGR, n = 8). Placental apelin gene expression was assessed by quantitative polymerase chain reaction.
  
  
  
  In the high-risk cohort, 4 fetuses developed isolated IUGR and 6 women developed PET. We obtained a median of 5 (range 2-9) hemodynamic and apelin measurements per woman. Apelin levels throughout gestation were best fitted by a quadratic curve. Apelin levels between 20 and 26 weeks gestation correlated with total peripheral resistance (r = .57, P = .01) and showed a trend toward an inverse correlation with stroke volume (r = -.42, P = .08). Apelin serum levels were 30% lower in pregnancies complicated by IUGR than in uncomplicated pregnancies or in women with preeclampsia (P = .009). Placental apelin gene expression was similar in IUGR, PET, preterm, and term normal placentas. Apelin staining was seen both in syncytiotrophoblast and stroma of the placental villi. In IUGR placentas, apelin staining was strongly decreased in both compartments compared to normals. Preeclamptic placentas showed an intermediate staining.
  
  
  
  Apelin levels mirror the cardiovascular changes seen in pregnancy. Serum and placental apelin levels are decreased in IUGR.
authors.affiliation: Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, Mount Sinai Hospital, University of Toronto, Toronto, Canada Department of Obstetrics and Gynecology, University Hospitals Leuven, Leuven, Belgium t.vanmieghem@gmail.com.
authors.forename: Tim
authors.initials: T
authors.lastname: Van Mieghem
authors.affiliation: Division of Obstetric Anesthesia, Department of Anesthesia, Mount Sinai Hospital, University of Toronto, Toronto, Canada.
authors.forename: Anne
authors.initials: A
authors.lastname: Doherty
authors.affiliation: Centre for Research in Women's and Infant's health, Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, University of Toronto, Toronto, Canada.
authors.forename: Dora
authors.initials: D
authors.lastname: Baczyk
authors.affiliation: Centre for Research in Women's and Infant's health, Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, University of Toronto, Toronto, Canada Centre for Trophoblast Research, Medical School Wayne State University, Detroit, MI, USA.
authors.forename: Sascha
authors.initials: S
authors.lastname: Drewlo
authors.affiliation: Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, Mount Sinai Hospital, University of Toronto, Toronto, Canada Feto-Maternal Medicine Unit, Department of Obstetrics and Gynecology, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland.
authors.forename: David
authors.initials: D
authors.lastname: Baud
authors.affiliation: Division of Obstetric Anesthesia, Department of Anesthesia, Mount Sinai Hospital, University of Toronto, Toronto, Canada.
authors.forename: Jose
authors.initials: J
authors.lastname: Carvalho
authors.affiliation: Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, Mount Sinai Hospital, University of Toronto, Toronto, Canada Centre for Research in Women's and Infant's health, Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, University of Toronto, Toronto, Canada.
authors.forename: John
authors.initials: J
authors.lastname: Kingdom
mesh_terms: D000328:Adult; D000073861:Apelin; D001794:Blood Pressure; D005260:Female; D005317:Fetal Growth Retardation / Q000097:blood / Q000453:epidemiology / Q000378:metabolism; D005865:Gestational Age; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins / Q000097:blood* / Q000378:metabolism; D008137:Longitudinal Studies; D010920:Placenta / Q000378:metabolism; D010927:Placental Insufficiency / Q000097:blood* / Q000453:epidemiology / Q000378:metabolism; D011225:Pre-Eclampsia / Q000097:blood / Q000453:epidemiology / Q000378:metabolism; D011247:Pregnancy
chemical_list: C115436:APLN protein, human; D000073861:Apelin; D036341:Intercellular Signaling Peptides and Proteins
keywords: apelin; endocrine; fetal; growth; growth restriction; physiology; preeclampsia