Integrating Microarrays into Routine Prenatal Diagnosis: Determinants of Decision Making

Abstract

Objectives: The explosion in genetic technologies, including array comparative genomic hybridization (aCGH), has increased the complexity of genetic counseling. We now offer chorionic villus sampling (CVS) and aCGH to all first-trimester patients, as this allows the prenatal diagnosis of an additional 1% of anomalies not otherwise detectable and can detect genetic copy number variants at a much higher resolution than conventional cytogenetics. Here, we explored some of the determinants of how patients are deciding to use or not use this new technology and evaluate risk-benefit analyses for that decision. Methods: This is a retrospective case-control study of singleton and multiples pregnancies at our center. Those having aCGH testing along with CVS were defined as ‘testers' and those who declined aCGH but had the CVS were ‘nontesters'. Results: Demographic data of 181 educated women who chose CVS were compared. Among those carrying singletons (n = 144), older women, defined as over 35 years of age (or ‘advanced maternal age'; AMA), were more likely to choose the aCGH than younger women. Further, women who had a prior history of genetic testing and who wanted to know the gender of the fetus were more likely to choose the aCGH test. In women carrying multiples (n = 37), AMA ceases to be a predictor of choice. Having had prior genetic counseling remains a strong predictor for choosing aCGH, as does wanting to know the gender of the fetus. Neither prior abortions nor having prior children were significant for women carrying singletons or multiples. Conclusion: Offering pregnant couples an individualized choice regarding aCGH seems an appropriate approach. There are discrete patterns associated with the choice of taking the aCGH that varied depending on whether the patient was carrying a singleton or multiples.

Epidemiology of fetal cerebral ventriculomegaly and evaluation of chromosomal microarray analysis versus karyotyping for prenatal diagnosis in a Chinese hospital

“…Chromosomal microarray analysis of copy-number variants (CNVs) is recommended as a first-tier clinical diagnostic test, giving an indication of intellectual and developmental delay in prenatal diagnosis. 1,2 Compared with current karyotyping, microarray analysis provides incremental value for the identification of genomic abnormalities in fetal DNA. 3 As reported, it can identify up to 20% additional genetic causes in fetuses accompanying structural anomalies.…”