Options for Down Syndrome Screening: What Will Women Choose?

Abstract

Down syndrome screening has been offered to pregnant women since the early 1980s. Protocols have changed as research confirmed improvements that result in higher detection rates and lower false-positive rates. Results from 2 clinical trials evaluating screening protocols that include ultrasound measurement of nuchal translucency and biochemical testing in the first and second trimester are now available. First-trimester screening is an option if there are adequate ultrasound, diagnostic, and counseling services available. Regional variation in the availability of these services may limit the implementation of first-trimester screening. Combining screening tests for Down syndrome from both trimesters as an integrated test offers the highest detection rate with the lowest false-positive rate. The possibility of avoiding a positive screen will make this an attractive option for some. Timing, detection rate, false-positive rates, and personal factors influence the decision women make regarding screening versus diagnostic testing. This article reviews the efficacy of current protocols for Down syndrome screening. Accurate information about available screening tests will facilitate informed decisions about screening and testing.

Prenatal Genetic Screening

“…The two types of diagnostic tests available are CVS, which is performed in the first trimester, and amniocentesis, which is performed in the second trimester. They are more costly than screening tests and, because of their invasive nature, they both contain an element of risk of pregnancy loss 1 . Therefore, many clinicians recommend them only when indicated following a positive screening test result, although ACOG has stated that clients should have the right to choose them for whatever reason.…”

“…The proven high rate of accuracy of these tests has resulted in a sharp decrease in the number of women undergoing the diagnostic procedures of amniocentesis and chorionic villus sampling (CVS). In the May/June 2005 issue of this journal, Grant 1 provided a detailed chronology of how these new strategies evolved.…”

Pregnancy associated plasma protein-A2: A novel biomarker for down syndrome

“…The issue of improved screening remains a priority due to the number of pregnant women affected, residual risk and false positive rates, and the serious ramifications with respect to reproductive health care (13–15). In the current study, we have evaluated the potential of pregnancy associated plasma protein-A2 (PAPP-A2) as a novel biomarker for screening pregnancies for Trisomy 21.…”

The clinical practice patterns of fetal ultrasonography in the first-trimester: A questionnaire survey of members of the Korean Society of Ultrasound in Obstetrics and Gynecology

“…Thus, first-trimester is an essential period for prenatal diagnosis. Most pregnant women want to know whether their baby is healthy as early as possible [2]. …”