title: Respiratory muscle strength: comparison between primigravidae and nulligravidae.
abstract: OBJECTIVE
  To describe and to compare MIP and MEP in primigravidae and nulligravidae in the 20-29 year age bracket and paired by age.
  
  
  METHODS
  We included 120 primigravidae with low obstetric risk (5th-40th week of gestation) and 40 nulligravidae. All of the participants were of normal weight and none exercised regularly. All were recruited from the metropolitan area of Recife, Brazil. Measurements of MIP and MEP were obtained from RV and TLC, respectively, with a digital manometer. We used Student's t-test to compare the two groups, and we used multiple linear regression in order to determine whether group or chronological age correlated with MIP or MEP.
  
  
  RESULTS
  In the primigravida and nulligravida groups, the mean MIP values were 88.50 ± 16.52 cmH₂O and 94.22 ± 22.63 cmH₂O, respectively, (p = 0.08), whereas the mean MEP values were 99.76 ±18.19 cmH₂O and 98.67 ± 20.78 cmH₂O (p = 0.75). Gestational age did not correlate with MIP (r = -0.06; p = 0.49) or MEP (r = -0.11; p = 0.22). The relationship between chronological age and MIP/MEP did not differ between primigravidae and nulligravidae (angular coefficient = 0.028 and 0.453, respectively).
  
  
  CONCLUSIONS
  Within this sample of women in the 20-29 year age bracket, the respiratory pressures of primigravidae remained stable during pregnancy and did not differ significantly from those of nulligravidae.
authors.affiliation: Professor Fernando Figueira Institute of Comprehensive Medicine, Recife, Brazil. lemosandrea@bol.com.br
authors.forename: Andrea
authors.initials: A
authors.lastname: Lemos
authors.forename: Ariani Impieri
authors.initials: AI
authors.lastname: Souza
authors.forename: Armele Dornelas de
authors.initials: AD
authors.lastname: Andrade
authors.forename: José Natal
authors.initials: JN
authors.lastname: Figueiroa
authors.forename: José Eulálio
authors.initials: JE
authors.lastname: Cabral-Filho
mesh_terms: D000328:Adult; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D016014:Linear Models; D008451:Maximal Voluntary Ventilation / Q000502:physiology; D053580:Muscle Strength / Q000502:physiology*; D010298:Parity / Q000502:physiology*; D011247:Pregnancy; D012132:Respiratory Muscles / Q000502:physiology*; D055815:Young Adult