title: Maternal flow-mediated dilation and nitrite concentration during third trimester of pregnancy and postpartum period.
abstract: OBJECTIVE
  To compare maternal flow-mediated dilation (FMD) of the brachial artery and nitrite concentration between third trimester of pregnancy (3rdT) and postpartum (PP) period. Additionally, we will evaluate whether FMD correlates with nitrite concentration in both periods.
  
  
  METHODS
  Eligibility criteria was healthy women with singleton pregnancy, gestational age >28 weeks, nonsmokers, and no personal or family history of vascular disease. Each women was examined during 3rdT and between 8 and 12 weeks PP to evaluate FMD and nitrite concentration in whole blood. Women not examined in both periods were excluded. Values between both periods were compared using paired t tests. Correlation between FMD and nitrite was examined by Pearson correlation coefficient. Significance level set as p < 0.05.
  
  
  RESULTS
  We invited 42 pregnant women. Among them, 35 were eligible and 7 of them were excluded for not attending the PP evaluation resulting in 28 participants analyzed. We found no significant change in FMD (10.39 ± 5.57% vs. 8.42 ± 4.21%; p = 0.11; 3rdT vs. PP, respectively) and no significant change in nitrite concentration (257.41 ± 122.95 nmol/L vs. 237.16 ± 90.01 nmol/L; p = 0.28). Baseline brachial artery diameter had a significant reduction (3.11 ± 0.30 to 2.75 ± 0.34 mm; p < 0.01). No significant correlation between FMD and nitrite during 3rdT (r = -0.13; p = 0.50) or PP (r = 0.14; p = 0.48) was found.
  
  
  CONCLUSIONS
  We did not observe significant changes in both FMD and nitrite concentration between third trimester and the PP period. FMD did not correlate with nitrite in both periods. More studies are needed to confirm our findings.
authors.affiliation: Departamento de Ginecologia e Obstetricia da Faculdade de Medicina de Ribeirao Preto, Universidade de Sao Paulo (FMRP-USP), Ribeirao Preto, Brazil. ahmiyague@gmail.com
authors.forename: Andre H
authors.initials: AH
authors.lastname: Miyague
authors.forename: Wellington P
authors.initials: WP
authors.lastname: Martins
authors.forename: Jaqueline S R
authors.initials: JS
authors.lastname: Machado
authors.forename: Ana C
authors.initials: AC
authors.lastname: Palei
authors.forename: Lorena M
authors.initials: LM
authors.lastname: Amaral
authors.forename: Danielle M
authors.initials: DM
authors.lastname: Teixeira
authors.forename: Valeria C
authors.initials: VC
authors.lastname: Sandrim
authors.forename: Jonas T C
authors.initials: JT
authors.lastname: Sertorio
authors.forename: Jose E
authors.initials: JE
authors.lastname: Tanus-Santos
authors.forename: Geraldo
authors.initials: G
authors.lastname: Duarte
authors.forename: Ricardo C
authors.initials: RC
authors.lastname: Cavalli
mesh_terms: D000293:Adolescent; D000328:Adult; D004730:Endothelium, Vascular / Q000502:physiology*; D005260:Female; D006801:Humans; D009573:Nitrites / Q000097:blood*; D049590:Postpartum Period / Q000502:physiology*; D011247:Pregnancy / Q000502:physiology*; D011263:Pregnancy Trimester, Third / Q000502:physiology*; D011446:Prospective Studies; D014664:Vasodilation; D055815:Young Adult
chemical_list: D009573:Nitrites