The effect of high altitude on birth weight in the Asir region, Saudi Arabia

Objective: To investigate the effect of altitude on fetal birth weight. Design: Crossectional randomized prospective study. Setting: Abha (3,000 meters) and Mohayel (500 meters) cities in southern Saudi Arabia. Subjects: Healthy pregnant Saudi women and their healthy newborn living permanently at the areas of study. Results: The mean birth weight was significantly greater at low altitude (3375 grams) than at high altitude (3207 grams) (P<0.001). The low birth weight observed at high altitude may be attributed to intrauterine hypoxia to which the fetus is subjected to. The intrauterine hypoxia appeared to be secondary to maternal hypoxia resulting from high altitude environment.