References: 1. Kratz A, Ferraro M, Sluss PM,
Lewandrowski KB. Laboratory reference values. N Engl J Med.
2004;351(15):1548-15632. PMID:15470219 2. Knight EM, et al. Biochemical profile of African American women
during three trimesters of pregnancy and at delivery. J Nutr.
1994;124:943S-953S. PMID:8201445