MATERNAL SERUM CA 125 LEVELS IN PREGNANCIES WITH CHROMOSOMALLY-NORMALAND CHROMOSOMALLY-ABNORMAL FETUSES

We measured the maternal serum cancer antigen 125 (MS-CA 125) levels i n 98 nonpregnant women, 765 first- and second-trimester pregnancies wi th chromosomally-normal fetuses, and 54 chromosomally-abnormal pregnan cies. To determine the MS-CA 125 concentration, we used a new automate d microparticle enzyme immunoassay with low inter-assay variability. T he median MS-CA 125 level decreased from the first to the second trime ster of pregnancy and was higher than that in non-pregnant women. We f ound no difference between normal and Down's syndrome (n=29) pregnanci es (t-test: t=0.57, p>0.5). The MS-CA 125 levels in pregnancies with o ther chromosomal abnormalities showed no difference either, compared w ith the normals. We conclude that MS-CA 125 is not a useful marker for fetal Down's syndrome, nor for other chromosomal disorders in pregnan cy.