title: Assessment of nitrite oxide and maternal-fetal Doppler parameters during pregnancy.
abstract: OBJECTIVE
  The objective was to evaluate and compare the whole blood nitrite concentration in the three trimesters of pregnancy. Additionally, we investigate whether there is any relation between nitrite concentrations and Doppler ultrasound analysis of some maternal and fetal vessels.
  
  
  METHODS
  Thirty-three healthy pregnant women were examined at the first (11-14 weeks), second (20-24 weeks) and third trimester (34-36 weeks) of pregnancy. In the three exams, we determined the maternal whole blood nitrite concentration and uterine arteries Doppler analysis to determine pulsatility index (PI), and resistance index (RI). In the second and third trimester we also performed fetal umbilical and middle cerebral arteries PI and RI. We compared the concentrations of nitrite in three trimesters and correlated with Doppler parameters.
  
  
  RESULTS
  No difference was observed in the whole blood nitrite concentrations across trimesters: 151.70 ± 77.90 nmol/ml, 142.10 ± 73.50 nmol/ml and 147.10 ± 87.30 nmol/ml; first, second and third trimesters, respectively. We found no difference in correlation between whole blood nitrite concentration and Doppler parameters from the evaluated vessels.
  
  
  CONCLUSIONS
  In healthy pregnant women, the nitrite concentrations did not change across gestational trimesters and there was also no strong correlation with Doppler impedance indices from maternal uterine arteries and fetal umbilical and middle cerebral arteries.
authors.affiliation: a Department of Obstetrics and Gynecology , Ribeirao Preto Medical School, University of Sao Paulo (FMRP-USP) , Ribeirão Preto - SP , Brazil .
authors.forename: Salim Demétrio
authors.initials: SD
authors.lastname: Jorge Neto
authors.affiliation: a Department of Obstetrics and Gynecology , Ribeirao Preto Medical School, University of Sao Paulo (FMRP-USP) , Ribeirão Preto - SP , Brazil .
authors.forename: Jackeline Souza Rangel
authors.initials: JS
authors.lastname: Machado
authors.affiliation: b Departament of Physiology and Biophysics , University of Mississipi Medical Center , Jackson , MS , USA .
authors.forename: Ana Carolina Tavares
authors.initials: AC
authors.lastname: Palei
authors.affiliation: a Department of Obstetrics and Gynecology , Ribeirao Preto Medical School, University of Sao Paulo (FMRP-USP) , Ribeirão Preto - SP , Brazil .
authors.forename: Wellington Paula
authors.initials: WP
authors.lastname: Martins
authors.affiliation: c Departament of Pharmacology , Botucatu Medical School, São Paulo State University (UNESP) , Botucatu - SP , Brazil .
authors.forename: Valéria Cristina
authors.initials: VC
authors.lastname: Sandrim
authors.affiliation: d Department 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
authors.affiliation: b Departament of Physiology and Biophysics , University of Mississipi Medical Center , Jackson , MS , USA .
authors.forename: Lorena Machado
authors.initials: LM
authors.lastname: Amaral
authors.affiliation: e Departament of Pharmacology , Ribeirão Preto Medical School, University of Sao Paulo (FMRP-USP) , Ribeirão Preto - SP , Brazil.
authors.forename: José Eduardo
authors.initials: JE
authors.lastname: Tanus-Santos
authors.affiliation: a Department of Obstetrics and Gynecology , Ribeirao Preto Medical School, University of Sao Paulo (FMRP-USP) , Ribeirão Preto - SP , Brazil .
authors.forename: Geraldo
authors.initials: G
authors.lastname: Duarte
authors.affiliation: a Department of Obstetrics and Gynecology , Ribeirao Preto Medical School, University of Sao Paulo (FMRP-USP) , Ribeirão Preto - SP , Brazil .
authors.forename: Ricardo Carvalho
authors.initials: RC
authors.lastname: Cavalli
mesh_terms: D000293:Adolescent; D000328:Adult; D002536:Cerebral Arteries / Q000000981:diagnostic imaging; D005260:Female; D006801:Humans; D009573:Nitrites / Q000097:blood*; D011247:Pregnancy; D011264:Pregnancy Trimesters / Q000097:blood*; D018608:Ultrasonography, Doppler; D016216:Ultrasonography, Prenatal; D014469:Umbilical Arteries / Q000000981:diagnostic imaging; D055988:Uterine Artery / Q000000981:diagnostic imaging; D055815:Young Adult
chemical_list: D009573:Nitrites
keywords: Doppler ultrasonography; nitrites; pregnancy