Serum biochemical parameters in pregnant women with and without fetal chromosomal abnornalities

Abstract

Aim. To analyse the levels of serum beta-human chorionic gonadotropin (β-hCG) and pregnancy-associated plasma protein A (PAPP-A) in pregnant women without fetal chromosomal abnormalities and with fetal trisomy 21 (Down syndrome) or 18 (Edwards syndrome).Materials and Methods. We performed a retrospective analysis of serum biochemical parameters of 1214 women who had previously undergone karyotyping as a part of prenatal or postnatal screening. Patients were stratified into those with a normal fetal karyotype, those carrying a fetus with trisomy 21, and those carrying a fetus with trisomy 18. Levels of serum β-hCG and PAPP-A were estimated using the AutoDELFIA automatic immunoassay system.Results. In most of the women carrying a fetus with trisomy 21, serum β-hCG has been increased as compared to the reference range. In contrast, women carrying a fetus with trisomy 18 generally had reduced serum β-hCG. In both cases, the level of serum PAPP-A has been decreased in comparison with a reference range. The proportion of women with a 2-fold reduced serum PAPP-A was 52.4% and 88.6% if carrying fetuses with trisomy 21 and trisomy 18, respectively.Conclusion. Serum b -hCG has been increased as compared to the reference range. In contrast, women carrying a fetus with trisomy 18 generally had reduced serum β-hCG. In both cases, the level of serum PAPP-A has been decreased in comparison with a reference range. The proportion of women with a 2-fold reduced serum PAPP-A was 52.4% and 88.6% if carrying fetuses with trisomy 21 and trisomy 18, respectively.Conclusion. Serum b-hCG and PAPP-A are sensitive markers of fetal trisomy 21 and trisomy 18 in pregnant women.