title: Reference range for the pulsatility index ductus venosus Doppler measurement between 11 and 13 + 6 weeks of gestation in a Brazilian population.
abstract: OBJECTIVE
  To establish reference range for the pulsatility index (PI) ductus venosus (DV) Doppler measurement between 11 and 13 + 6 weeks of gestation in a Brazilian population.
  
  
  METHODS
  A retrospective cross-sectional study was performed with 430 singleton pregnancies. The PI DV Doppler measurement was performed as routine during the first trimester screening. DV was identified by color Doppler and the pulsed Doppler gate was placed in the distal portion of the umbilical sinus. When at least three typical DV waveforms were obtained, PI DV was measured manually in one waveform. Polynomial regression was used to obtain the best fit using PI DV Doppler measurement and crown-rump length (CRL) with adjustments by the determination coefficient (R(2)). 5th, 50th and 95th percentiles for the PI DV Doppler measurements at each gestational were determined.
  
  
  RESULTS
  The mean of PI DV Doppler measurement was 1.1 ± 0.2 (range 0.8-3.7). The linear regression was the best fit: PI DV measurement = 1.288-0.0034*CRL (R(2 )= 0.03).
  
  
  CONCLUSIONS
  Reference range for the PI DV Doppler measurement between 11 and 13 + 6 weeks of gestation in a Brazilian population was established.
authors.affiliation: a 1Mario Palmério University Hospital - University of Uberaba (UNIUBE) , Uberaba-MG , Brazil .|b 2Radiologic Clinic of Uberaba (CRU) , Uberaba-MG , Brazil .
authors.forename: Alberto Borges
authors.initials: AB
authors.lastname: Peixoto
authors.affiliation: a 1Mario Palmério University Hospital - University of Uberaba (UNIUBE) , Uberaba-MG , Brazil .|b 2Radiologic Clinic of Uberaba (CRU) , Uberaba-MG , Brazil .
authors.forename: Taciana Mara Rodrigues da Cunha
authors.initials: TM
authors.lastname: Caldas
authors.affiliation: c 3Department of Obstetrics and Gynecology, Ribeirão Preto Medical School, University of São Paulo (DGO-FMRP-USP) , Ribeirão Preto-SP , Brazil .
authors.forename: Wellington P
authors.initials: WP
authors.lastname: Martins
authors.affiliation: a 1Mario Palmério University Hospital - University of Uberaba (UNIUBE) , Uberaba-MG , Brazil .
authors.forename: Polyana Costa
authors.initials: PC
authors.lastname: Ferreira
authors.affiliation: d 4Department of Obstetrics, Paulista School of Medicine, Federal University of São Paulo (EPM-UNIFESP) , São Paulo-SP , Brazil , and.
authors.forename: Luciano Marcondes Machado
authors.initials: LM
authors.lastname: Nardozza
authors.affiliation: e 5Department of Perinatal Medicine, Royal Women's Hospital, and Department of Obstetrics and Gynaecology, University of Melbourne , Melbourne , Victoria , Australia.
authors.forename: Fabricio Da Silva
authors.initials: Fda S
authors.lastname: Costa
authors.affiliation: d 4Department of Obstetrics, Paulista School of Medicine, Federal University of São Paulo (EPM-UNIFESP) , São Paulo-SP , Brazil , and.
authors.forename: Edward
authors.initials: E
authors.lastname: Araujo Júnior
mesh_terms: D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D011247:Pregnancy; D011673:Pulsatile Flow; D012016:Reference Values; D012189:Retrospective Studies; D018608:Ultrasonography, Doppler; D016216:Ultrasonography, Prenatal; D014471:Umbilical Veins / Q000000981:diagnostic imaging* / Q000502:physiology
keywords: Brazilian population; Doppler; ductus venosus; first trimester; reference range