title: Chorionic plate artery function and Doppler indices in normal pregnancy and intrauterine growth restriction.
abstract: BACKGROUND
  In fetal growth restriction (FGR) abnormal umbilical artery (UA) Doppler waveform indices suggest increased vascular resistance and impaired placental blood flow. This study aimed to determine whether UA Doppler waveform indices were related to the vasoreactivity of placental chorionic plate small arteries in normal and FGR pregnancies.
  
  
  METHODS
  UA Doppler waveform analysis was performed 24 h before delivery in 23 normal term and 15 FGR pregnancies. Post-delivery responses of chorionic plate arteries to vasoactive agents were examined using the technique of wire myography.
  
  
  RESULTS
  Altered vascular reactivity to agonists was demonstrated in chorionic plate arteries in FGR pregnancy. Constriction to U46619 (thromboxane mimetic) and relaxation to sodium nitroprusside (nitric oxide donor) were significantly increased in the arteries of FGR pregnancies compared with normal pregnancies. No relationship existed between Doppler indices and chorionic plate responses in normal or FGR pregnancies.
  
  
  CONCLUSIONS
  Fetoplacental vascular reactivity is altered in FGR pregnancy independently of UA Doppler waveform indices. Altered function may be additive to the pathophysiology underlying abnormal Doppler waveforms and could contribute to the inappropriate control of vascular tone in FGR.
authors.affiliation: Maternal & Fetal Health Research Centre, St Mary's Hospital for Women and Children, Division of Human Development, University of Manchester, Manchester, UK.
authors.forename: T A
authors.initials: TA
authors.lastname: Mills
authors.forename: M
authors.initials: M
authors.lastname: Wareing
authors.forename: G J
authors.initials: GJ
authors.lastname: Bugg
authors.forename: S L
authors.initials: SL
authors.lastname: Greenwood
authors.forename: P N
authors.initials: PN
authors.lastname: Baker
mesh_terms: D019796:15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid / Q000494:pharmacology; D000328:Adult; D016022:Case-Control Studies; D002823:Chorion / Q000098:blood supply*; D005260:Female; D005317:Fetal Growth Retardation / Q000000981:diagnostic imaging* / Q000503:physiopathology; D006801:Humans; D066298:In Vitro Techniques; D009213:Myography; D009599:Nitroprusside / Q000494:pharmacology; D010920:Placenta / Q000098:blood supply; D011247:Pregnancy; D018709:Statistics, Nonparametric; D018608:Ultrasonography, Doppler; D016216:Ultrasonography, Prenatal; D014469:Umbilical Arteries / Q000000981:diagnostic imaging* / Q000503:physiopathology; D014655:Vascular Resistance / Q000187:drug effects; D014662:Vasoconstrictor Agents / Q000494:pharmacology; D014665:Vasodilator Agents / Q000494:pharmacology
chemical_list: D014662:Vasoconstrictor Agents; D014665:Vasodilator Agents; D009599:Nitroprusside; D019796:15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid