PROSTATE-SPECIFIC ANTIGEN IN AMNIOTIC-FLUID OF NORMAL AND ABNORMAL PREGNANCIES

Objective: To examine if prostate-specific antigen (PSA) is present in amniotic fluid or maternal serum during pregnancy and if its presence is associated with fetal abnormalities. Methods: Samples tested inclu ded amniotic fluids from 853 pregnant women for whom amniocentesis was performed; 312 nonpregnant women who donated blood; 259 pregnant wome n who donated blood at Various gestational ages. Amniotic fluid or ser um PSA was measured with an ultrasensitive time-resolved immunofluorom etric procedure. 372 pregnancies were studied for the presence of geno typic or phenotypic fetal abnormalities. Results: PSA was present in m ost amniotic fluids, the median PSA concentration increased from gesta tional week 11 to 22 and stabilized thereafter until delivery. The mos t prominent PSA concentration change occurred during gestational weeks 13-14. Pregnant women had significantly higher serum PSA concentratio ns than nonpregnant women; the pattern of serum PSA concentration chan ge during pregnancy was similar to that of amniotic fluid; however, se rum PSA concentrations were lower by a factor of 20-40. No association existed between amniotic fluid PSA and maternal age, gender of fetus, or length of abstinence of mother from sexual intercourse. After gest ational week 15, fetuses with trisomy 21 or 18, anencephaly, or renal disorders were associated with low amniotic fluid PSA levels. Conclusi on: Our data suggest that PSA may play a role in fetal development, es pecially at gestational ages between 13-20 weeks. The diagnostic usefu lness of PSA in identifying fetal abnormalities remains to be determin ed.