A comparison of fetal growth curves at altitude and sea level

Objective: To study intrauterine growth at an altitude of 5,200 feet in order to determine the most appropriate standard of birthweight charts to be used at this altitude. Methods: A total of 3,147 singleton deliveries were reviewed to determine (1) birth weight, (2) residence at an altitude of 5,200 feet, (3) dating of pregnancy. A total of 1,621 cases were included, and birthweights were compared with birthweights from California and Denver. We performed a one-sample t test at each week of gestational age. A P value of less than 0.003 was considered significant. Results: (1) there was a significant difference in birthweight between Albuquerque and Denver after 37 weeks; (2) there was no difference between birthweights in Albuquerque and California; (3) Hispanic babies were significantly smaller than Angle-American babies. Conclusion: Neonates born at 5,200 feet above sea level fit growth curves developed at sea level in California in 1981 and not those obtained in babies born at altitudes in Denver in 1963. These observations may be the result of the differences in nutritional intake by the pregnant women and improved prenatal care.