In the early 1970s the first report on the potential value of amniotic fluid alpha-fetoprotein (AF) measurement for the prenatal diagnosis of open neural-tube defects (NTDs) appeared, and then second report of the UK Collaborative AFP study
described
accurately that the overlap in values between affected and NTD pregnancies. Amniotic fluid AFP measurement has now become one of the standard tools of the prenatal diagnostic laboratory and is usually applied to all amniotic fluids whatever the
indication for amniocentesis.
In order to establish the normal range of the amniotic fluid AFP, and used to basic screening program for detection of fetal anomalies, amniotic fluid AFP levels studied in 161 pregnant women who visited Department of Obstetrics and Gynecology,
Keimyung
University. The study group was selected with normal karyotype at prenatal genetic diagnosis and normal baby at delivery with follow up. The amniotic fluid AFP levels were obtained by the microparticle enzyme immunoassay. The results were as
follows.
Age distribution was from 22 to 44 years of age. The indication of the amniocentesis were previous birth of Down's syndrome (50 cases), elderly gravida (38 cases), previous birth of congenital anomaly (28 cases), recurrent pregnancy loss without
chromosomal anomaly (19 cases), high maternal serum AFP (10 cases), previous birth of mental retardation (5 cases), congenital anomaly at the relatives (5 cases), anxiety of fetal anomaly (4 cases), maternal and parenteral chromosomal
translocation
(2
cases). The median value of amniotic fluid at each gestational age showed 18.2㎍/ml at 14 weeks, 17.7㎍/ml at 15 weeks, 16.9㎍/ml at 16 weeks, 13.3㎍/ml at 17 weeks, 11.0㎍/ml at 18 we4eks, 10.2㎍/ml at 19 weeks 8.2㎍/ml at 20 weeks, 5.2㎍/ml at
21
weeks, 3.1㎍/ml at 22 weeks and decreased progressively with advancing pregnancy and all values were within over 0.4 multiple of median (MOM) and below 2.0 MOM.
Authors consider that the amniotic fluid AFP measurement would be helpful in detection of fetal anomalies during midtrimester pregnancy and it indeed should be included as a routine prenatal screening method with acethylcholinesterase assay.
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