title: Graduated effects of high-altitude hypoxia and highland ancestry on birth size.
abstract: BACKGROUND
  We present a cohort of ca. 25,000 birth records from Bolivia of men and women who are currently adults. We used this cohort to test the hypothesis that high altitude reduces birth weight and that highland ancestry confers graduated protection against this effect.
  
  
  METHODS
  Birth records were obtained from obstetric clinics and hospitals in La Paz (3,600 m) and Santa Cruz (420 m). Only singleton, healthy term (>37 wk) pregnancies of nonsmoking mothers were included. Andean, Mestizo, or European ancestry was determined by validated analysis of parental surnames.
  
  
  RESULTS
  High altitude reduced body weight (3,396 ± 3 vs. 3,090 ± 6 g) and length (50.8 ± 0 vs. 48.7 ± 0 cm) at birth (P < 0.001). Highland ancestry partially protected against the effects of high altitude on birth weight (Andean = 3,148 ± 15 g; Mestizo = 3,081 ± 6 g; and European = 2,957 ± 32 g; trend P < 0.001) but not on birth length. The effects of high-altitude pregnancy on birth size were similar for male and female babies.
  
  
  CONCLUSIONS
  High altitude reduces birth weight and highland native ancestry confers graduated protection. Given previous studies linking reduced birth weight with increased risk of cardiovascular disease, further study is warranted to test whether adults from high-altitude pregnancy are at increased risk of developing cardiovascular disease.
authors.affiliation: Instituto Boliviano de Biología de Altura, La Paz, Bolivia.
authors.forename: Rudy
authors.initials: R
authors.lastname: Soria
authors.affiliation: Department of Emergency Medicine, Altitude Research Center, University of Colorado, Denver, Colorado.
authors.forename: Colleen G
authors.initials: CG
authors.lastname: Julian
authors.affiliation: Instituto Boliviano de Biología de Altura, La Paz, Bolivia.
authors.forename: Enrique
authors.initials: E
authors.lastname: Vargas
authors.affiliation: Department of Obstetrics/Gynecology, University of Colorado, Denver, Colorado.
authors.forename: Lorna G
authors.initials: LG
authors.lastname: Moore
authors.affiliation: Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, UK.
authors.forename: Dino A
authors.initials: DA
authors.lastname: Giussani
mesh_terms: D000328:Adult; D000531:Altitude; D001724:Birth Weight; D001827:Body Height; D001838:Bolivia; D015331:Cohort Studies; D005006:Ethnicity; D005260:Female; D006801:Humans; D000860:Hypoxia / Q000503:physiopathology*; D007231:Infant, Newborn; D008297:Male