Related Experiment Videos
Maternal serum alpha-fetoprotein and altitude.
K L Nuttall1, R R Lenke, E R Ashwood
1Department of Pathology, University of Utah, Salt Lake City, UT, USA. nuttall@arup-lab.com
Medical Hypotheses
|April 28, 2000
Summary
Maternal serum alpha-fetoprotein (MS-alphaFP) levels decrease with increasing altitude. Adjusting for altitude may reclassify some screening results for fetal defects.
Area of Science:
- Obstetrics and Gynecology
- Prenatal Screening
- Biomedical Research
Background:
- Maternal serum alpha-fetoprotein (MS-alphaFP) is a key biomarker for prenatal screening of fetal abnormalities.
- MS-alphaFP levels are influenced by various factors including gestational age, maternal weight, and plurality.
- Geographic factors, specifically altitude, have been suggested but not fully investigated as potential confounders.
Purpose of the Study:
- To investigate the impact of varying altitudes on MS-alphaFP concentrations.
- To determine if altitude adjustment is necessary for accurate interpretation of MS-alphaFP screening results.
Main Methods:
- Analysis of 1063 MS-alphaFP results from women residing at different altitudes.
- Application of linear regression models with and without an altitude term.
- Calculation of multiple-of-the-median (MoM) values before and after altitude adjustment.
Main Results:
- A statistically significant inverse correlation was observed between altitude and MS-alphaFP levels.
- Median MS-alphaFP decreased by approximately 1 ng/mL for every 1100 ft increase in altitude.
- Altitude adjustment led to the reclassification of 3.4% of patient results.
Conclusions:
- Altitude is a significant geographic factor influencing MS-alphaFP levels.
- Adjusting MS-alphaFP MoM values for altitude may improve screening accuracy.
- Further research is needed to establish the clinical utility of altitude-adjusted MS-alphaFP screening.