title: Respiratory function of very prematurely born infants at follow up: influence of sex.
abstract: OBJECTIVE
  To test the hypothesis that male compared with female prematurely born infants would have worse lung function at follow up.
  
  
  METHODS
  Prospective follow up study.
  
  
  METHODS
  Tertiary neonatal intensive care units
  
  
  METHODS
  Seventy six infants, mean (SD) gestational age 26.4 (1.5) weeks, from the United Kingdom oscillation study.
  
  
  METHODS
  Lung function measurements at a corrected age of 1 year.
  
  
  METHODS
  Airways resistance (Raw) and functional residual capacity (FRC(pleth)) measured by whole body plethysmography, specific conductance (sGaw) calculated from Raw and FRC(pleth), and FRC measured by a helium gas dilution technique (FRC(He)).
  
  
  RESULTS
  The 42 male infants differed significantly from the 34 female infants in having a lower birth weight for gestation, requiring more days of ventilation, and a greater proportion being oxygen dependent at 36 weeks postmenstrual age and discharge. Furthermore, mean Raw and FRC(pleth) were significantly higher and mean sGaw significantly lower. After adjustment for birth and current size differences, the sex differences in FRC(pleth) and sGaw were 15% and 26% respectively and remained significant.
  
  
  CONCLUSIONS
  Lung function at follow up of prematurely born infants is influenced by sex.
authors.affiliation: Department of Child Health, 4th Floor Golden Jubilee Wing, King's College Hospital, London SE5 9RS, UK.
authors.forename: M R
authors.initials: MR
authors.lastname: Thomas
authors.forename: L
authors.initials: L
authors.lastname: Marston
authors.forename: G F
authors.initials: GF
authors.lastname: Rafferty
authors.forename: S
authors.initials: S
authors.lastname: Calvert
authors.forename: N
authors.initials: N
authors.lastname: Marlow
authors.forename: J L
authors.initials: JL
authors.lastname: Peacock
authors.forename: A
authors.initials: A
authors.lastname: Greenough
mesh_terms: D000403:Airway Resistance / Q000502:physiology; D005260:Female; D005500:Follow-Up Studies; D005652:Functional Residual Capacity; D006801:Humans; D007231:Infant, Newborn; D007235:Infant, Premature, Diseases / Q000503:physiopathology*; D008173:Lung Diseases, Obstructive / Q000503:physiopathology; D008297:Male; D011446:Prospective Studies; D012044:Regression Analysis; D012120:Respiration Disorders / Q000503:physiopathology*; D012307:Risk Factors; D012680:Sensitivity and Specificity; D012727:Sex Characteristics