To the Editor: Dr Smith-Bindman and colleagues1 concluded that ultrasound screening in the second trimester is not an efficacious screening method for fetal Down syndrome.
Their analysis and conclusions focused primarily on 6 isolated ultrasonographic markers for Down syndrome, and they did not fully consider associated fetal structural malformations, which occur in 28% of fetuses with Down syndrome or multiple markers.2 Table 3 of the article shows that when multiple markers and structural abnormalities are considered together, ultrasound screening has a sensitivity of 69% and a false-positive rate of 8%. The PPVs cited also are underestimated because their prevalence rates for Down syndrome are low. In 1997, there was an overall second-trimester prevalence of Down syndrome in the United States of 1:504. For women aged 35 years or older, the prevalence was 1:134.3 Using these prevalence rates, ultrasound screening had a PPV of 1.68%, that is, 1 in 60 screen-positive women had an affected pregnancy.
Register and get free email Table of Contents alerts, saved searches, PowerPoint downloads, CME quizzes, and more
Subscribe for full-text access to content from 1998 forward and a host of useful features
Activate your current subscription (AMA members and current subscribers)
Purchase Online Access to this article for 24 hours
Country-Specific Mortality and Growth Failure in Infancy and Yound Children and Association With Material Stature
Use interactive graphics and maps to view and sort country-specific infant and early dhildhood mortality and growth failure data and their association with maternal
Instructions
Thank you for submitting a comment on this article. It will be reviewed by JAMA editors. You will be notified when your comment has been published. Comments should not exceed 500 words of text and 10 references.
Do not submit personal medical questions or information that could identify a specific patient, questions about a particular case, or general inquiries to an author. Only content that has not been published, posted, or submitted elsewhere should be submitted. By submitting this Comment, you and any coauthors transfer copyright to the journal if your Comment is posted.
* = Required Field
Disclosure of Any Conflicts of Interest* Indicate all relevant conflicts of interest of each author below, including all relevant financial interests, activities, and relationships within the past 3 years including, but not limited to, employment, affiliation, grants or funding, consultancies, honoraria or payment, speakers’ bureaus, stock ownership or options, expert testimony, royalties, donation of medical equipment, or patents planned, pending, or issued. If all authors have none, check "No potential conflicts or relevant financial interests" in the box below. Please also indicate any funding received in support of this work. The information will be posted with your response.
Some tools below are only available to our subscribers or users with an online account.
Download citation file:
Web of Science® Times Cited: 4
Customize your page view by dragging & repositioning the boxes below.
More Listings atJAMACareerCenter.com >
and access these and other features:
Register Now
Enter your username and email address. We'll send you a link to reset your password.
Enter your username and email address. We'll send instructions on how to reset your password to the email address we have on record.
Need assistance?
Athens and Shibboleth are access management services that provide single sign-on to protected resources. They replace the multiple user names and passwords necessary to access subscription-based content with a single user name and password that can be entered once per session. It operates independently of a user's location or IP address. If your institution uses Athens or Shibboleth authentication, please contact your site administrator to receive your user name and password.