The value of minor ultrasound markers for fetal aneuploidy

Abstract

As a result of improvements in ultrasound image quality and scanning technique, an increasing number of subtle morphological changes in fetal anatomy have been identified in the second trimester. Most of these ultrasound features were originally described as normal variants of development with no clinical significance. However, subsequent studies in high-risk populations showed that some of these variants were more prevalent in fetuses with chromosomal defects and therefore proposed as prenatal markers for the detection of aneuploidy. The implications for pregnancy management when one of these so-called minor ultrasound markers is detected have been a matter of continuous controversy in the field of prenatal diagnosis and yet the definitive answer on their clinical significance in the low-risk population is still debated.

Choroid plexus cysts do not affect fetal neurodevelopment

“…CPCs are more prevalent in fetuses with trisomies 18 and 21, but the degree to which an isolated finding elevates risk for aneuploidy and whether parents should be informed of the finding remains the topic of vigorous debate. 1,[5][6][7][8] However, neither side of this debate disputes the tenet that isolated CPCs, when not associated with abnormal karyotypes, are benign variants of periventricular development without implications for subsequent pregnancy or child outcomes.…”

Choroid Plexus Cysts

“…CPC detected on ultrasound at 18 to 20 weeks warrants an additional sonogram of the fetal hands, heart, and central nervous system by an experienced sonographer to search for other abnormalities. 49 The nature of the cyst should be fully explained to the patient, as well as the risks associated with trisomy 18 and 21, along with modifying risk factors, such as maternal age, serum markers, and other sonogram findings. The option for genetic testing should be explained along with its risks and benefits.…”

Ultrasound Imaging of Fetal Brain Abnormalities

“…42 The diagnosis of brain anomalies in the fetus therefore must depend upon constant landmarks that could be documented in normal fetuses. 44,45 Once an abnormality is documented at any of these levels, neonatal correlation of the abnormality becomes possible because these same landmarks can be reliably reproduced in the neonate. Three levels of imaging comprise the minimum planes that will satisfy these guidelines.…”