Health News Review

Prenatal screening for Down syndrome and other birth defects has for decades been an anxious rite of passage for many pregnant women. For many, especially those over 35, the joy of finding out they are pregnant is tempered by weeks of anxiety as they await the fourth month of their pregnancy for the tests to be done.
Not anymore. For the first time since such prenatal chromosome screening was introduced in 1990, women of any age can choose to have screening tests done 11 to 13 weeks into their pregnancy. Not only does that cut down on the waiting time, but the newer tests are better than the older ones at predicting the likelihood that a fetus has some of the most common and serious chromosomal abnormalities.

Our Review Summary

This story discusses first trimester screening for prenatal chromosomal abnormalities, namely Down syndrome. A study in the New England Journal of Medicine (NEJM) looked at sequential screening of women 10-13 weeks into their pregnancy, instead of the typical 16 week screening. Combining blood tests and ultrasound screening succeeded in finding 87% of Down fetuses (though a positive test is still only a prediction of increased risk that a baby will be born with Down syndrome). The journalist did not mention the false positive rate of the 1st trimester vs. 2nd trimester screenings in the NEJM study, nor the study design. However, a discussion of what constitutes a “positive” result of screening was a plus for this story. The story also was balanced in presenting the risks of screening and the risk of miscarriage due to subsequent diagnostic tests, such as chorionic villus sampling or CVS (sampling cells via a thin tube or needle inserted into the placenta) and amniocentesis. There was no discussion of the cost of these tests earlier in the


Criteria

Not Satisfactory

Does the story adequately discuss the costs of the intervention?

Not Satisfactory

No information about the cost

of the screening or diagnostic tests, either alone or in combination. No information if both forms of testing in first

trimester are covered by insurance.

Satisfactory

Does the story adequately explain/quantify the harms of the intervention?

Satisfactory

Mentions harms of miscarriage with the

CVS testing and amniocentesis. Briefly mentions psychological harm of screening if you do not want to go through with more

risky diagnostic tests–more anxiety during the pregnancy if you have a positive Down result in screening.

Not Satisfactory

Does the story seem to grasp the quality of the evidence?

Not Satisfactory

No mention of study design, although

discussion of design in this case (sequential treatment for all participants vs. randomization to control and treatment

groups) was not crucial to interpreting results of the study. No mention of false positive rate. (About 5% with first

trimester combined screening.)

Satisfactory

Does the story commit disease-mongering?

Satisfactory

Frames risk factors of more invasive diagnostic tests and the

risk of screening (in terms of anxiety if you choose not to have the further tests).

Satisfactory

Does the story use independent sources and identify conflicts of interest?

Satisfactory

Potential conflict of interest is not discussed, but there are a number of local experts in

ob/gyn quoted, however no patients. Nobody cited affiliated with the New England Journal of Medicine study, upon which the

story is based.

Satisfactory

Does the story compare the new approach with existing alternatives?

Satisfactory

Mentions alternatives of second trimester testing or no screening at all, but seems to promote the

screening. Gives estimate of miscarriage with diagnostic tests.

Not Satisfactory

Does the story establish the availability of the treatment/test/product/procedure?

Not Satisfactory

Story address the

greater demand for 1st trimester testing, but does not address availability in smaller hospitals, nor is there a discussion

that there is specialized training and a certification process for nunchal translucency (the ultrasound test) for both

sonographers and physicians.

Satisfactory

Does the story establish the true novelty of the approach?

Satisfactory

Mentions that combination of

screening methods provide greater accuracy sooner in pregnancy. Neither is a “new’ test, however.

Total Score: 6 of 9 Satisfactory


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