Amniotic Fluid Alpha-Fetoprotein Levels during Midtrimester Pregnancy

Kim, J I; Jeon, H J; Kim, T H

Abstract

In order to establish the normal range of the amniotic fluid alpha-fetoprotein (AFAFP), and use to basic screening program for detection of fetal anomalies, AFAFP levels were measured by radioimmunoassay in 780 pregnant women for variety of indications of amniocentesis from January, 1992 to December, 1996. The median value of AFAFP in Korean pregnant women were 16,819.3 ng/ml, 16,563.5 ng/ml, 14,368.6 ng/ml, 12,576.3 ng/ml, 9,916.8 ng/ml, and 8,544.8 ng/ml at 15 weeks, 16 weeks, 17 weeks, 18 weeks, 19 weeks, 20 weeks, and then declined gradually as gestational weeks increased. Upper cut-off level of AFAFP was 42,048.25 ng/ml (2.5 MoM) at 15 weeks, 49,690.5 ng/ml (3.0 MoM) at 16 weeks, 43,105.8 ng/ml (3.0 MoM) at 17 weeks 37,728.9 ng/ml (3.0 MoM) at 18 weeks, 34,708.8 ng/ml (3.5 MoM) at 19 weeks, 29,906.8 ng/ml (3.5 MoM) at 20 weeks, respectively. This preliminary determination of the median value and the normal range of AFAFP by each gestation week in uncomplicated women would provide normal cut-off level for prenatal diagnosis of genetic disorders and AFAFP should be included as a routine prenatal screening with acethylcholinesterase assay.