New ACOG Practice Bulletin Regarding Fetal Aneuploidy Screening
In the January issue of Obstetrics and Gynecology (2007;109:217-227), the American College of Obstetricians and Gynecologists (ACOG) published its revised recommendations on “Screening for Chromosomal Abnormalities” during pregnancy. It is one of the most comprehensive reviews I have ever seen presented on any subject in an ACOG Practice Bulletin; it presents an overview of a complex subject in very understandable terms; and, I am sure it will be a “milestone” in helping to establish first trimester screening for aneuploidy as a standard of care in the U.S., not only for ‘at risk’ women, but for all pregnant women, something that has already been widely accepted and implemented over the past decade in other industrialized nations.
The review points out the advantages and disadvantages of aneuploidy screening compared to diagnostic testing, the many different options for screening, and the value of combined and sequential assessments in terms of increasing screen detection rates and minimizing false positive results. It also recognizes the current limitations to providing all options to all patients, encouraging a flexible approach based on “tests…available in your area”…and “the needs of your patients.” For example, even if a provider does not have the special training and certification necessary for combined risk assessment, requiring nuchal translucency measurement, the option for “serum integrated screening (i.e., maternal blood tests done in late first and early midtrimesters)” can be offered with detection rates for trisomies 21, 13, and 18 in the range of 85-88%! Quite frankly, I believe at some point, the need for ultrasound specialty training for initial screening, and its inherent subjectivity, regardless of standardization and certification, will be replaced by a reliable panel of serum markers in the not-to-distant future anyway. I also believe that within the next 10 years, fetal diagnosis of aneuploidy by detection of cells and DNA in maternal serum will replace the diagnostic studies (chorionic villus sampling and amniocentesis) we currently rely upon, thereby, eliminating the barrier of ‘risk’ imposed by these invasive procedures.
Anyway, if you are interested in the subject, as either patient or provider, I would commend this practice bulletin to you. And, while you are reading that, I am going to work on my 'birth plan...'