Chorid Plexuscysts

I have just reached the 30th anniversary of the first obstetrical sonogram I performed. Even having witnessed each of the technological advancements in sonography over those three decades, it is still difficult to comprehend the enormous improvements in image quality that have occurred. These improvements have brought sonography from a "promising" diagnostic tool to a mainstay of modern imaging. However, nowhere in medicine has this technique had a more profound impact than in the field of obstetrics. Thirty years ago there was essentially no such thing as obstetrical imaging and prenatal diagnosis was in its infancy.

During this time obstetrical sonography went from a medical oddity to a test of such great value that several European countries perform at least two obstetrical sonograms in every pregnant woman and 70% of modern American mothers have had a sonogram during their pregnancy (1,2). Obstetrical sonograms provide a wealth of useful information to the primary care giver. Some of these benefits are easily measured: accuracy of estimating menstrual age, accuracy of predicting twins, etc. Others are more difficult to measure but we all agree are nonetheless of great benefit. One of the most important of these is providing "reassurance" to the expectant mother. In our Obstetrical Department the phrase "for size and dates and general reassurance" seems to be pasted on nearly all sonogram request forms. Personally, the opportunity to say, "everything looks fine" to an expectant mother was one of the perks of my job. I can see the wave of relief wash across her face. It's always a touching moment followed by "thank you, Doctor".

Today, I no longer feel that way. There are a growing number of patients where I dread having to speak to her. I have reviewed the sonographer's scans and they disclose a finding that will send the mother into a tailspin of confusion and worry. I'm not talking about holoprosencephaly or bilateral renal agenesis. I have a great deal of experience discussing such devastating diagnoses with pregnant women. And while the news is sad, I always feel that I am providing the family with a great service. Nothing can change the fact that her fetus has a mortal anomaly. There will necessarily be a grieving period and tears will undoubtedly flow, but beginning that grieving period at the earliest possible date in her pregnancy is "good medicine".

Tomorrow when I return to work the odds are I will have to speak to a mother-to-be about an "abnormality" that I see on her sonogram and I won't know what to tell her. I am talking about "abnormal" findings on her sonogram which loosely fit under the general heading of "Down syndrome markers" (some are actually better as markers of other trisomy syndromes). I am not referring to atrio-ventricular canal or duodenal atresia. These are strong indicators that the Down syndrome may be present. But Down syndrome or not, the fetus still has a serious anomaly and the detection of that anomaly is a benefit. What I am afraid to encounter tomorrow is an "abnormality" which is not really abnormal: choroid plexus cysts (3-31), echogenic intracardiac foci (32-36), mild pyelectasis (37-41), and echogenic bowel (42-45) . If her fetus has one of these "abnormalities" but doesn't have the Down syndrome, then her fetus is normal. Excuse me, I'm certain I will be criticized if I don't tell the mother-to-be that in the absence of the Down syndrome and the presence of echogenic bowel she must worry about her fetus having cystic fibrosis, developing intrauterine growth restriction, having a premature birth, a fetus with a cytomegalovirus infection, or a fetus who may die in her womb (46-49). Alternatively, if her fetus has mild pyelectasis and a normal karyotype her newborn child is at risk for urinary tract problems, must take antibiotics after birth, get an extensive and uncomfortable work-up for vesico-ureteral reflux and must be followed-up for many months to ensure normalcy (50).

The sheer numbers of papers written on the subject only add credibility to their importance (3-49). Certainly, some authors disagree as to the importance of one or the other of these findings (51,52). Unfortunately, the physician performing a routine sonogram and finding one of these "markers" is hard pressed to make a determination regarding which expert to believe. Inevitably they choose the "safest" path; at least, "safest" from a medico-legal perspective. The mother is simply going to have to deal with the possibility that her fetus may have the Down syndrome or worse.

These Down syndrome markers are common findings in normal fetuses, particularly the echogenic intracardiac focus (EIF). EIF occurs in approximately