Non-invasive prenatal diagnosis for Down syndrome: no paradigm shift, just better testing... and it is already here!

Non-invasive prenatal testing for aneuploidy and beyond: challenges of responsible innovation in prenatal screening

This paper contains a joint ESHG/ASHG position document with recommendations regarding responsible innovation in prenatal screening with non-invasive prenatal testing (NIPT). By virtue of its greater accuracy and safety with respect to prenatal screening for common autosomal aneuploidies, NIPT has the potential of helping the practice better achieve its aim of facilitating autonomous reproductive choices, provided that balanced pretest information and non-directive counseling are available as part of the screening offer. Depending on the health-care setting, different scenarios for NIPT-based screening for common autosomal aneuploidies are possible. The trade-offs involved in these scenarios should be assessed in light of the aim of screening, the balance of benefits and burdens for pregnant women and their partners and considerations of cost-effectiveness and justice. With improving screening technologies and decreasing costs of sequencing and analysis, it will become possible in the near future to significantly expand the scope of prenatal screening beyond common autosomal aneuploidies. Commercial providers have already begun expanding their tests to include sex-chromosomal abnormalities and microdeletions. However, multiple false positives may undermine the main achievement of NIPT in the context of prenatal screening: the significant reduction of the invasive testing rate. This document argues for a cautious expansion of the scope of prenatal screening to serious congenital and childhood disorders, only following sound validation studies and a comprehensive evaluation of all relevant aspects. A further core message of this document is that in countries where prenatal screening is offered as a public health programme, governments and public health authorities should adopt an active role to ensure the responsible innovation of prenatal screening on the basis of ethical principles. Crucial elements are the quality of the screening process as a whole (including non-laboratory aspects such as information and counseling), education of professionals, systematic evaluation of all aspects of prenatal screening, development of better evaluation tools in the light of the aim of the practice, accountability to all stakeholders including children born from screened pregnancies and persons living with the conditions targeted in prenatal screening and promotion of equity of access.

Imperfect informed consent for prenatal screening: Lessons from the Quad screen

Objective

The study evaluated patient informed consent (IC) for the Quad screen and examined differences in IC between test acceptors and test refusers. A multidimensional model of IC was used.

Methods

Women seeking prenatal care at nine obstetrics clinics in a large Midwestern city completed surveys between February and December 2006. Surveys contained measures for three dimensions of IC: intention, understanding and controlling influence.

Results

56.2% of women did not meet criteria for all three of our dimensions of IC and therefore failed to give it. The failure rate was higher among women who choose to screen (72.6%) than women who choose not screen (50%) (p < 0.001). Women who met all criteria for IC were over three times less likley to choose to screen (or = 0.32, CI 0.17–0.62 ( p < 0.01)) than women who did not meet criteria for IC.

Conclusion

The decision to screen for fetal anomalies is less of a deliberated action than the decision not to screen. Women who lack a fundamental understanding of the purpose and nature of the screen may be operating on the belief that the screen is part of standard care and presents no need to deliberate.

Screening of trisomy 21 nowadays. Is maternal age so important?

Introduction: Trisomy 21 is the most common chromosomal abnormality, therefore, screening and diagnosis of this disorder is in the centre of attention worldwide. An efficient screening method is the combined test based on maternal age, ultrasound signs, biochemical markers, and a risk ratio can be calculated based on these data. Aim: The aim of the authors was to determine the causes of missed prenatal diagnosis of Down’s syndrome at the 2nd Department of Obstetrics and Gynecology, Semmelweis University. Method: A retrospective study was carried out by collecting data from medical records of mothers who had delivered a newborn with Down’s syndrome in the Department between 2008 and 2012. Each medical record was analyzed individually. Results: In most cases the missed diagnosis of Down’s syndrome occurred when the expectant mother failed to attend the first trimester screening or did not take the risk of invasive diagnostic procedures needed for fetal kariotyping. Conclusions: Analysis of fetal DNA circulating in maternal plasma can be a solution for those who refuse invasive fetal diagnostics. This test has high sensitivity and very low false positive rate. It has become available since the end of 2011 in the United States and, since the autumn of 2012, in Hungary, too. The test, however, is not reimbursed by national health insurance. Orv. Hetil., 2013, 154, 1026–1030.