PHOENIX, ARIZ. — The presence of an isolated intracardiac echogenic focus on fetal ultrasound does not increase the risk for aneuploidy in the absence of other risk factors in women younger than 35 years of age, Kathleen Bradley, M.D., reported at the annual meeting of the Pacific Coast Obstetrical and Gynecological Society.
Consequently, amniocentesis may not be indicated in these patients, she said.
Dr. Bradley and her associates conducted a study that involved 10,875 patients who had an ultrasound evaluation in the second trimester at Cedars-Sinai Medical Center, Los Angeles, from 1997 to 1999.
A total of 176 cases, or 1.6%, of fetal intracardiac echogenic foci (IEF) were identified. Among them, 80% had an isolated IEF finding, and 20% had other ultrasound findings.
Abnormal karyotypes were identified in the fetuses of three IEF patients. Each of the three patients was at least 35 years old. The three fetuses all had trisomy 21, according to Dr. Bradley, a perinatologist in Tarzana, Calif.
“Our findings suggest that there is not an increased risk of aneuploidy with isolated IEF where there are no other risk factors in women” aged 35 or younger, Dr. Bradley said at the meeting, which was cosponsored by the American College of Obstetricians and Gynecologists.
Dr. Bradley noted a larger study of 12,672 patients evaluated in the second trimester. There were 479 cases of IEF and 11 cases of trisomy 21. Only one fetus with trisomy 21 had an isolated echogenic focus (J. Ultrasound Med. 2004;23:489–96).
“These trends may be helpful for current clinical management,” Dr. Bradley said. She urged a move toward individualized risk assessment to include factors such as advanced maternal age, biochemical screening, and all ultrasound markers, given a relative risk for each soft marker.
“It is important to determine a critical cutoff level to offer invasive clinical diagnosis. Should we use the current age-based risk or the procedure-related risk?” she asked. In addition, Dr. Bradley noted that of the 97 patients involved in the study and who underwent amniocentesis, there were no procedure-related losses.
In a comment on the study, Roger Rowles, M.D., a Yakima, Wash., ob.gyn., emphasized that the findings, along with the larger study, offer important insights into the use of amniocentesis for isolated intracardiac echogenic foci.
“The reasonable conclusion is that finding an IEF should prompt a detailed anatomic survey and, in the absence of other ultrasound markers and risk factors, patients should not be offered amniocentesis,” he said.