title: B-type natriuretic peptide and echocardiography reflect volume changes during pregnancy.
abstract: OBJECTIVE
  To evaluate B-type natriuretic peptide (BNP) and N-terminal pro-B-type natriuretic peptide (NT-proBNP) and cardiac structure and function in normal women through pregnancy and the postpartum.
  
  
  METHODS
  In this prospective observational study, we obtained serial transthoracic echocardiograms, BNP, and NT-proBNP at seven intervals from 6 weeks' gestation through 12 months postpartum. Women with hypertension or cardiac disease were excluded. Using 6-12 months postpartum as reference for non-pregnant levels, echocardiogram measurements and BNP/NT-proBNP were compared over time using linear mixed models with Tukey-Kramer adjustment for multiple comparisons.
  
  
  RESULTS
  Of 116 patients, data was available for 78-114 healthy pregnant or postpartum women within each time interval, and 102 patients provided data for ≥4 intervals. Compared to 6-12 months postpartum, BNP and NT-proBNP remained stable through pregnancy and delivery, increased within 48 h postpartum (P<0.0001), then returned to baseline. Left ventricular volume increased within 48 h postpartum (P=0.021) while left atrial volume increased at 18-24 weeks (P=0.0002), 30-36 weeks (P<0.0001) and within 48 h postpartum (P=0.002). The transmitral early/late diastolic velocity (E/A) ratio, transmitral early/peak mitral annulus diastolic velocity (E/E') ratio, isovolumic relaxation times, and mitral valve deceleration times were similar within 48 h and 6-12 months postpartum.
  
  
  CONCLUSIONS
  In normal women, BNP/NT-proBNP, left atrial, and left ventricular volumes increase within 48 h postpartum without indications of altered diastolic function.
authors.affiliation: .
authors.forename: Janet M
authors.initials: JM
authors.lastname: Burlingame
authors.affiliation: .
authors.forename: Kelly
authors.initials: K
authors.lastname: Yamasato
authors.affiliation: .
authors.forename: Hyeong Jun
authors.initials: HJ
authors.lastname: Ahn
authors.affiliation: .
authors.forename: Todd
authors.initials: T
authors.lastname: Seto
authors.affiliation: .
authors.forename: W H Wilson
authors.initials: WHW
authors.lastname: Tang
mesh_terms: D000328:Adult; D004452:Echocardiography; D005260:Female; D006801:Humans; D020097:Natriuretic Peptide, Brain / Q000097:blood*; D049590:Postpartum Period; D011247:Pregnancy / Q000097:blood*; D011446:Prospective Studies; D012016:Reference Values
chemical_list: D020097:Natriuretic Peptide, Brain
keywords: Brain; echocardiography; natriuretic peptide, pregnancy; postpartum period