Choroid Plexus Cyst and Echogenic Intracardiac Focus in Women at Low Risk for Chromosomal Anomalies
Filly RA, Benacerraf BR, Nyberg DA, Hobbins JC
J Ultrasound Med 23:447–449, 2004 449
The ultrasound community involved with obstetric sonography has been grappling with a controversial issue for a number of years. The issue centers on the so-called soft markers for Down syndrome (trisomy 21) and other trisomic chromosomal anomalies. Recently, the issue has been hotly debated at major meetings of medical organizations involved in sonographic diagnosis, including the American Institute of Ultrasound in Medicine (AIUM) and the Society of Radiologists in Ultrasound. Importantly, both “sides” of the argument were well intentioned. What emerged from these debates was the realization that experts on “opposite” sides of the argument were actually closer to agreement than they had previously thought when it came to the identification of some of these soft markers in lowrisk women. Many of these soft markers have been described. However, 2 of these markers have been the source of the greatest controversy. These are the choroid plexus cyst (CPC) and the echogenic intracardiac focus (EIF). This document is directed solely at these 2 findings in women at low risk for aneuploidy and not at other soft markers that have been reported in the literature or their significance in women at high risk for aneuploidy.
The EIF is considered a soft marker for trisomies 21 and 13, whereas the CPC is considered a marker predominantly for trisomy 18. The soft markers for Down syndrome were originally described to help improve the sonographic detection of Down syndrome in highrisk women (predominantly pregnant women of advanced maternal age) who were attempting to gather more accurate risk information than that based on age alone before deciding whether to proceed to amniocentesis. Inevitably, after the publication of these research studies on the soft markers in high-risk women, sonologists in the general practice of obstetric sonography wondered what to report as the significance of these findings when they were discovered in low-risk women. To date, the prevalent practice in the United States has been to report these findings and to state that the presence of such findings increases the risk of aneuploidy. Whether one subscribes to the notion that these findings alter the risk of aneuploidy in a fetus or do not, it is increasingly clear that women confronted with the information that their fetus has a “marker” for a chromosomal anomaly are often caused to endure a great deal of anxiety. The signatories of this document believe that the anxiety caused by discussing the presence of a CPC or an EIF with a low-risk pregnant woman is needless when that is the only “abnormal” feature noted on the sonogram. Furthermore, there is no substantive evidence that this “harm” is offset by a measurably greater “good” (ie, detection of an appropriately greater number of fetuses with Down syndrome or trisomy 18). We believe that a large number of practitioners have discovered for themselves that the reporting of these 2 findings causes more harm than good. However, taking independent action to stop reporting these findings is nearly impossible with the professional liability environment that exists in the United States today. We hope to offer a compromise that will help end the controversy surrounding the reporting of EIFs and CPCs and mitigate the professional liability risk associated with this issue.
We recommend that when a CPC or an EIF is the only detected abnormality (ie, it is an isolated marker on a second- or third-trimester sonogram that meets the most recently adopted AIUM performance guidelines) that the sonographic report emphasize that, as an isolated finding in a patient otherwise considered at low risk for fetal aneuploidy, a CPC or an EIF is not considered clinically significant and does not change her from low- to high-risk status (see below).
The following statement and recommendations meet these needs and may be used either as an example or a template:
1. A (CPC or EIF) is identified. Although this finding has been reported in association with fetal chromosome abnormalities, no other major or minor anomalies were identified in this fetus. In the absence of other risk factors, this is considered a normal variant, and no further evaluation is recommended.
2. The attending obstetrician is notified so that the risk status of the patient can be ascertained. (In many clinical situations, the attending obstetrician may be the individual who performed the sonography and recognized the CPC or EIF. As well, the sonologist may be a maternal-fetal medicine consultant who could then make the final determination regarding the patient’s risk status.) The AIUM guidelines should be strictly followed. Furthermore, when an EIF is identified, it is necessary to evaluate for other sonographic markers of trisomy 21, such as nuchal thickness. Similarly, when a CPC is identified, it is necessary to exclude other sonographic markers of trisomy 18, such as “clenched” hands. These additional efforts will help add to the certainty that the EIF or CPC is a normal variant in a low-risk woman. If difficulty is encountered obtaining the views of the fetus recommended by the AIUM guidelines, the foregoing statements may not apply, and referral for a “targeted” scan may be necessary. Risk status is ascertained preferably by the patient’s biochemical screening test results (the so-called triple or quadruple markers). Low risk is defined as anyone having a “negative” biochemical screen or, in the absence of biochemical information, a maternal age of younger than 35 years.
It is realized that on occasion there is a clinical backdrop that might possibly increase the risk in patients in this low-risk category, so the decision of whether to counsel these patients regarding the relationship of the CPC or EIF to fetal aneuploidy is at the discretion of the appropriate provider. Examples of such patients would be women whose biochemical risk was “screen-negative” but the actual estimated risk was very close to the cutoff for “screen-positive” or those whose risk for fetal aneuploidy, for any reason, is substantially elevated above their age-related risk. In most instances, the appropriate provider to determine the patient’s risk status would be the attending obstetrician but may be a consultant evaluating the patient for such risks. If the risk status is judged to be low, then no further workup is required, and the physicians need not discuss the finding with the patient with regard to fetal aneuploidy. Under these circumstances, the CPC or EIF is appropriately considered a normal variant.
(The signatories understand that some practitioners believe that it is important to discuss every unusual finding with the patient because the fetus’ risk of aneuploidy is a spectrum, and “high” and “low” risk statuses are somewhat arbitrarily defined and vary to some degree in different regions of the United States.) The signatories concur with this approach and offer it as a compromise solution to this vexing problem. Importantly, because the signatories are well-known experts in obstetric sonography, the above recommendations also represent their expert opinion with regard to future professional liability suits that may follow the implementation of the approach outlined above by general sonologists and their obstetric colleagues. However, it is not the intention of this document to protect sonologists who perform abbreviated obstetric sonographic examinations that fail to meet AIUM performance guidelines, nor is it our intention to imply that physicians who discuss the implications of EIFs or CPCs with their patients are creating harm to them.