[Effect of high altitude on birth weight and adverse perinatal outcomes in two Argentine populations].
BACKGROUND
Depending on the geographical altitude the purpose of this work was to analyze in two argentine populations the variation of birth weight (BW) and adverse perinatal outcomes, adjusting for maternal and obstetric factors.


METHODS
Data from 4000 births in the provinces of Jujuy and 4000 in Buenos Aires (Sarda Maternity Hospital) (1996-2000) recruited and randomized from the Perinatal Information System was used. The data were grouped according to an altitudinal gradient composed by Sarda Maternity (20 masl) and the geographic regions of Jujuy province: Ramal (500 masl), Valle (1200 masl), Quebrada (2500 masl) and Puna (3500 masl). Outcome variables were BW > 3000 g, BW <2500 g, ponderal index (PI), prematurity, small for gestational age (SGA) and intrauterine growth restriction (FGR), while potentially confounding variables were: age, type of partner, education, overweight, obesity, smoking, hypertension, preeclampsia, urinary infection, growth restriction and cesarean section.


RESULTS
An increasing altitudinal gradient for adolescent mothers (<19 years) and decreasing for the rest of the maternal obstetric variables was observed. The BW, BW>3000 g, BW<2500 g and PI were negatively associated with altitude (p <0.001). Prematurity, SGA and FGR showed an opposite trend (p <0.001). Adjusted for confounding variables BW <3000 g, SGA, FGR<0.90 and PI <2.53 showed an increased risk with geographical altitude (p <0.05).


CONCLUSIONS
Altitude was independently associated with BW restriction and adverse perinatal outcomes. Given the impact of BW reduction in the risk of chronic no communicable diseases this relationship in other populations, regardless of their location altitude, should be assess.
Carlos
C
Grandi
José
J
Dipierri
Guillermo
G
Luchtenberg
Angélica
A
Moresco
Emma
E
Alfaro
D000293:Adolescent; D000328:Adult; D000531:Altitude; D000532:Altitude Sickness / Q000150:complications; D001118:Argentina; D001724:Birth Weight / Q000502:physiology*; D001827:Body Height / Q000502:physiology; D005260:Female; D047109:Fetal Development / Q000502:physiology; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D008423:Maternal Age; D011247:Pregnancy; D011248:Pregnancy Complications / Q000209:etiology; D011256:Pregnancy Outcome; D011272:Pregnancy, Multiple; D012307:Risk Factors; D055815:Young Adult