ABSTRACT
OBJECTIVE: The objective of the study was to evaluate the performance of first trimester combined screening in cases of placental/fetal, mosaic or non-mosaic, autosomal trisomy other than trisomy 21, 18, or 13, and in cases of aneuploidy for a marker chromosome with focus on biochemical markers. METHOD: We identified 66 cases in three large databases including 357 675 pregnancies from October 2003 to January 2014. RESULTS: Seventy-seven percent of the 66 cases were screened positive at the combined first trimester screening (cFTS) for trisomy 21 or trisomy 18 or 13. The multiple of median (MoM) of Pregnancy Associated plasma protein A (PAPP-A) of the different aneuploidy groups ranged from 0.2 to 0.5 MoM, whereas the MoM of maternal serum free - ß - human chorionic gonadotropin (FßhCG) was approximately 1.0 MoM. The exceptions being 0.2 MoM for cases involving chromosome 8 (n = 7) and 0.5 MoM for cases involving chromosome 9 (n = 3). The nuchal translucency MoM was approximately 1.0 MoM in all aneuploidy groups. CONCLUSION: The cFTS program for trisomy 21, 18, and 13 is also sensitive to a broad range of rare chromosomal trisomies and chromosomal mosaicisms, primarily because of a strong detection capacity of PAPP-A MoM.
Subject(s)
Chorionic Gonadotropin, beta Subunit, Human/blood , Mosaicism , Pregnancy-Associated Plasma Protein-A/metabolism , Trisomy/diagnosis , Adult , Biomarkers/metabolism , Chromosome Disorders/diagnosis , Chromosome Disorders/diagnostic imaging , Chromosome Disorders/metabolism , Chromosomes, Human, Pair 13/diagnostic imaging , Chromosomes, Human, Pair 13/metabolism , Chromosomes, Human, Pair 18/diagnostic imaging , Chromosomes, Human, Pair 18/metabolism , Chromosomes, Human, Pair 8/diagnostic imaging , Chromosomes, Human, Pair 8/metabolism , Chromosomes, Human, Pair 9/diagnostic imaging , Chromosomes, Human, Pair 9/metabolism , Databases, Factual , Down Syndrome/diagnosis , Down Syndrome/diagnostic imaging , Down Syndrome/metabolism , Female , Humans , Middle Aged , Nuchal Translucency Measurement , Pregnancy , Pregnancy Trimester, First , Prenatal Diagnosis , Trisomy 13 Syndrome , Trisomy 18 Syndrome , Young AdultABSTRACT
We present a foetus affected by trisomy 9, a rare chromosomal disorder, which was diagnosed in a low-risk patient during the first trimester of pregnancy. The finding of multiple structural foetal anomalies at the first trimester screening prompted chorionic villus sampling. Evaluation of the quantitative fluorescent polymerase chain reaction was normal, but the final karyotype result revealed a diagnosis of trisomy 9. First trimester screening for detection of foetal anomalies is highly effective. Although rapid molecular methods are available for prenatal diagnosis of common autosomal and sex chromosome aneuploidies, it is essential to obtain a full karyotype in order to exclude the less commonly encountered chromosomal abnormalities.
