AMNIOTIC-FLUID PREALBUMIN AS A POTENTIAL MARKER OF FETAL ABNORMALITIES

Normal amniotic fluid prealbumin (PAB) levels between 16 and 41 weeks of pregnancy are demonstrated in 175 samples from various gestational ages. PAB was measured quantitatively by immunonephelometry and qualit atively estimated by electrophoresis while total protein was measured by colorimetry. The percent of PAB values in the total protein content is inversely correlated to the gestational age. Fetal abnormalities a nd abnormal conditions in pregnancy diagnosed in the second trimester and early third trimester (16-32 weeks) show significantly (p < 0.01) higher than expected PAB values (25.9 +/- 4.6 mg/l, range 19.5-35.6, n = 23) in comparison to normal fetuses and normal pregnancies of the s ame age (13.6 +/- 3.6 mg/l, range 4.3-19.8, n = 87). The remaining 65 samples of normal third trimester amniotic fluid were evaluated in com parison to the second trimester normal values, and an inverse correlat ion in respect to advancing pregnancy was observed. PAB values were co rrected for the total protein content and the resulting ratio had the lowest variation compared to PAB and total protein values. It is propo sed that PAB, although not specific for a particular disorder, express ed as a ratio of the total protein content is a potential biochemical marker for certain fetal defects and complications of pregnancy.