The Effect of Inhibin A on Prenatal Screening Results for Down Syndrome in the High Risk Czech Pregnant Women.

Background: Currently, prenatal testing is based on an ultrasound examination, the testing of certain biochemical markers and, most recently, also on the analysis of fragments from the extracellular DNA of the fetus in the mother´s blood. The aim of this work was to verify whether inhibin A testing during pregnancy can help influence the risk distribution of Down syndrome screening results in high risk population and thus possibly reduce the number of unnecessarily invasive procedures, or for better stratification of risks when deciding on non-invasive DNA testing.

Methods: The concentrations of inhibin A were measured using a chemiluminescent immunoassay in two groups of screening tests.

Importance of the integrated test in the Down's syndrome screening algorithm.

Objective: In the Czech Republic, over 97% of all pregnant women undergo some type of antenatal screening for Down's syndrome. In about 95% of cases with a confirmed fetal chromosomal abnormality, the pregnancy is terminated. The most commonly used test is the first trimester combined test.

Maternal plasma DNA testing for aneuploidy in pregnancies achieved by assisted reproductive technologies.

Purpose: We sought to compare measurements of circulating cell-free DNA as well as Down syndrome test results in women with naturally conceived pregnancies with those conceived using assisted reproductive technologies.

Methods: Data regarding assisted reproductive technologies were readily available from seven enrollment sites participating in an external clinical validation trial of nested case/control design. Measurements of circulating cell-free fetal and total DNA, fetal fraction (ratio of fetal to total DNA), chromosome-specific z-scores, and karyotype results were available for analysis.