Maternal weight correction for α-fetoprotein: Mathematical truncations revisited Academic Article uri icon


MeSH Major

  • Body Weight
  • alpha-Fetoproteins


  • The objective of this study was to determine if maternal weight correction as implemented 20 years ago for alpha-fetoprotein (AFP) testing is still appropriate, and what should be the weight cutoff for correction. AFP measurements from 44,951 biochemical screening cases from a single laboratory were divided by maternal weight, and separated into high >/=2.5 multiples of the median (MOM), and low <0.4 MOM. Without weight correction, AFP values are still skewed to lower levels of higher maternal weight (1.1% >/= 2.5 MOM). Using a truncated range to 200 lbs. (for women greater than 200), produces more uniform results than using an upper cutoff of 250 for truncation (2.7% vs 5.0% >/= 2.5 MOM). The same relationship is seen for "lows." Without correction, higher weight lowers AFP, correction to 250 lbs. overcompensates, and 200 lbs. gives the most even distribution, and, therefore, optimizes the distribution of highs.

publication date

  • September 2002



  • Academic Article



  • eng

Digital Object Identifier (DOI)

  • 10.1089/109065702761403405

PubMed ID

  • 12490064

Additional Document Info

start page

  • 221

end page

  • 3


  • 6


  • 3