Prenatal diagnosis of chromosomal polymorphisms: most commonly observed polymorphism on Chromosome 9 have associations with low PAPP-A values*

AbstractIntroduction: To identify the prevalence and types of fetal chromosomal polymorphisms in pregnant women and to examine possible associations with screening test parameters.Materials and methods: Fetal chromosomal polymorphism rate was investigated in pregnant women who had been implemented for invasive prenatal test in a tertiary reference center in Thrace Region of Turkey. Fetal chromosomal polymorphisms were determined and their effects on screening tests’ parameters were investigated. Possible differences in the first and second-trimester screening test parameters between women; with fetal chromosomal polymorphism who had screening test results (Group 1) and those with a normal karyotype (Group 2) were evaluated.Results: Fetal chromosomal polymorphism prevalence was 5.3% (n = 101). The most common polymorphisms were identified on chromosome 9, 1, and 16 [54.5% (n = 55); 8.9% (n = 9), and 6.9% (n = 7), respectively]. The most common polymorphic variant was 9qh+ (n = 23; 22.8%). Among the screeni...