title: Assessment of endothelial function in normal twin pregnancy.
abstract: OBJECTIVE
  To assess the maternal endothelial function in normal twin pregnancy.
  
  
  METHODS
  Cross-sectional study.
  
  
  METHODS
  Endothelial function was investigated in 74 women with normal twin pregnancy at 11-30 weeks of gestation and the results were compared to previous reported findings in 98 women with normal singleton pregnancy and 19 non-pregnant controls.
  
  
  METHODS
  Endothelial function was assessed by measuring the changes of the brachial artery diameter in response to reactive hyperemia (flow-mediated dilatation) using external high resolution ultrasound.
  
  
  RESULTS
  Flow-mediated dilatation of the brachial artery in both twin and singleton pregnancies was significantly higher than in non-pregnant women (P = 0.002 and P = 0.02, respectively). However, there was no significant difference in flow-mediated dilatation between women with twin and singleton pregnancy (9.61 +/- 4.36 vs. 8.84 +/- 3.18, P = 0.38). Resting vessel size, baseline flow and reactive hyperemia did not change significantly with gestation in twin pregnancy and were similar to values in singleton pregnancies and controls.
  
  
  CONCLUSIONS
  Our findings indicate that although in pregnancy endothelial function is enhanced, this change may not be affected by the number of fetoplacental units present.
authors: Harris Birthright Research Centre for Fetal Medicine, King's College Hospital, London, UK.
authors: M D
authors: MD
authors: Savvidou
authors: A E
authors: AE
authors: Donald
authors: K H
authors: KH
authors: Nicolaides
mesh_terms: D000328:Adult; D001916:Brachial Artery / Q000000981:diagnostic imaging / Q000502:physiology; D003430:Cross-Sectional Studies; D004730:Endothelium, Vascular / Q000502:physiology*; D005260:Female; D005865:Gestational Age; D006801:Humans; D006940:Hyperemia / Q000503:physiopathology; D011247:Pregnancy; D011272:Pregnancy, Multiple / Q000502:physiology*; D016216:Ultrasonography, Prenatal; D014664:Vasodilation / Q000502:physiology*