title: Placental expression of soluble fms-like tyrosine kinase 1 is increased in singletons and twin pregnancies with intrauterine growth restriction.
abstract: OBJECTIVE
  Intrauterine growth restriction (IUGR) is characterized by decreased placental perfusion. Low oxygen has been shown to increase soluble fms-like tyrosine kinase 1 (sFlt-1) expression in the human placenta. The objective of this study was to examine sFlt-1 expression in different types of IUGR pregnancies, including early-onset severe cases characterized by abnormal umbilical and uterine artery Doppler and discordant IUGR twins in which the normal cotwin represents the optimal control because both placentas share the same uterine environment.
  
  
  METHODS
  Placentas from four subgroups were collected: early severe IUGR with umbilical artery absent end diastolic flow (n = 19), small for gestational age with normal uterine and umbilical artery Doppler (n = 11), severely growth-restricted dichorionic and monochorionic twins with abnormal umbilical artery Doppler (n = 9), preeclamptic twins (n = 3), and age-matched normal singletons (n = 19) and twin controls (n = 8).
  
  
  RESULTS
  Expression of sFlt-1 mRNA and protein was significantly increased in IUGR placentas compared with small for gestational age and normal control placentas. sFlt-1 expression levels were also significantly greater in the small IUGR twin placentas from discordant twin pregnancies compared with the normal cotwin. In preeclamptic twins, sFlt-1 expression was increased in only one of the two placentas.
  
  
  CONCLUSIONS
  Our results demonstrate that sFlt-1 expression is increased in severe IUGR placentas with abnormal umbilical artery Doppler of singletons and also in discordant IUGR twins. Reduced placental perfusion may contribute to the increased expression of sFlt-1 in IUGR pregnancies. Our data are compatible with differential sFlt-1 expression in placentas from discordant twins.
authors.affiliation: Department of Obstetrics and Gynecology, Mount Sinai Hospital, 600 University Avenue, Room 871C, Toronto, Ontario, Canada M5G 1X5.
authors.forename: Ori
authors.initials: O
authors.lastname: Nevo
authors.forename: Ariel
authors.initials: A
authors.lastname: Many
authors.forename: Jing
authors.initials: J
authors.lastname: Xu
authors.forename: John
authors.initials: J
authors.lastname: Kingdom
authors.forename: Ettore
authors.initials: E
authors.lastname: Piccoli
authors.forename: Stacy
authors.initials: S
authors.lastname: Zamudio
authors.forename: Martin
authors.initials: M
authors.lastname: Post
authors.forename: Alan
authors.initials: A
authors.lastname: Bocking
authors.forename: Tullia
authors.initials: T
authors.lastname: Todros
authors.forename: Isabella
authors.initials: I
authors.lastname: Caniggia
mesh_terms: D000328:Adult; D015153:Blotting, Western; D005260:Female; D005317:Fetal Growth Retardation / Q000201:enzymology*; D006801:Humans; D007150:Immunohistochemistry; D007231:Infant, Newborn; D007236:Infant, Small for Gestational Age; D010920:Placenta / Q000098:blood supply / Q000201:enzymology*; D011225:Pre-Eclampsia / Q000201:enzymology*; D011247:Pregnancy; D011272:Pregnancy, Multiple / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014427:Twins; D018608:Ultrasonography, Doppler; D014469:Umbilical Arteries / Q000000981:diagnostic imaging; D040281:Vascular Endothelial Growth Factor Receptor-1 / Q000096:biosynthesis* / Q000235:genetics
chemical_list: C501162:FLT1 protein, human; D040281:Vascular Endothelial Growth Factor Receptor-1