Determination of the risk of aneuploidy by screening tests and prenatal diagnosis by quantitative fluorescent polymerase chain reaction

Human plasental lactogen (hPL) is synthesised by placenta and found in maternal serum. In Down syndrome affected placentas, hPL synthesis is reduced. Quantitative Fluorescent Polymerase Chain Reaction (QF-PCR) is used for rapid diagnosis of aneuploidies in recent years. The aim of this study is to investigate potential of hPL as maternal serum marker for fetal aneuploidies and efficacy of QF-PCR in diagnosis.Serum levels of hPL were measured in first trimester 85 low-risk, 23 high-risk pregnancies and in second trimester 84 low-risk, 51 high-risk pregnancies. Medians for each day were determined with hPL levels of low-risk pregnants. MoM values appropriate gestational age were calculated. QF-PCR was performed in 26 pregnants admitted for hemoglobinopathy to Prenatal Diagnosis Unit and in 2 high-risk pregnants undergone invasive prenatal testing.hPL MoM values of Down syndrome pregnancies in first and second trimester high-risk groups were identified respectively as 0,77 and 1,50. Karyotypes of these two cases were determined as 47,XX+21 by QF-PCR. In one of 26 cases with normal karyotype by QF-PCR, karyotype of fetus was determined as 46,XX-92,XXXX mosaic tetraploid by cytogenetic analysis. The sensitivity, specificity, positive predictive value and negative predictive value of QF-PCR was calculated respectively as 66.6 %, 100 %, 100 % and 96 %.Consequently, hPL can be used in addition to the current first-trimester screening tests, however large prospective studies are required for the assessment of the potential of hPL. Nevertheless, QF-PCR is a reliable method for rapid diagnosis of aneuploidies with high sensitivity and specificity rates.