NEW YORK (Reuters Health) - A review of published studies suggests that chorionic villus sampling (CVS) for prenatal diagnosis may be associated with an increased risk of infantile hemangioma and possibly limb defects.
In the December issue of the Journal of Craniofacial Surgery, Dr. Lewis B. Holmes of Massachusetts General Hospital for Children, Boston, who conducted the review, notes that several reports published in the 1990s suggested that there were occasional fetal effects of CVS.
"Only a few studies have been conducted on the occurrence of hemangiomas in CVS-exposed infants," he emphasizes. In one study, reports Dr. Holmes, researchers found "cavernous or strawberry hemangiomas" in 12 of 95 CVS-exposed infants (12.6%) compared with 3 of 87 amniocentesis-exposed infants (3.4%).
In another study, the incidence of hemangioma was 21.1% in 578 consecutive CVS-exposed infants versus 7.4% in 445 consecutive mid-trimester amniocentesis-exposed infants. There were multiple hemangiomas in the CVS-exposed group (6.9%), but not in the amniocentesis group (p < 0.001). Multiple hemangiomas were also more common in infants exposed to trans-cervical CVS (10.3%) compared with trans-abdominal CVS (2.8%).
One postulated mechanism, Dr. Holmes notes, "is embolization of angioblasts or endothelial cells from the placenta to the fetal skin."
He also looked at the evidence for an association between CVS and birth defects involving the limbs, especially the fingers, and found some "clear" correlations. The evidence suggests that these risks are greater when CVS is performed earlier in pregnancy, such as at 8 to 9 weeks gestation.
In one large study, Dr. Holmes reports, researchers found that hypoplasia or the absence of any two fingers occurred in 1 of 3,372 CVS-exposed infants compared to 1 of 53,751 unexposed infants.
In a multi-state case-control study from 1988 through 1992, the absolute risk of terminal transverse limb defects was 1 in 2,900 (0.03%). "The risk for this type of deformity was six-times more common in CVS-exposed infants in comparison to the unexposed," he notes.
Dr. Holmes also reports that a "distinctive type of limb defect has been identified in several CVS-exposed infants: absence of the distal portion of the third finger with tapering and stiffness of the interphalangeal joints."
"The postulated mechanisms for the fetal injury included blood loss, hypoperfusion, hypoxia, endothelial cell damage, hemorrhage and tissue loss," Dr. Holmes notes. More research, he concludes, is needed to help determine whether and how CVS leads to an increased risk of hemangiomas and other defects.
In a written statement, Dr. Mutaz B. Habal, Director of the Tampa Bay Craniofacial Center in Florida, and Editor-in-Chief of the Journal of Craniofacial Surgery notes that because CVS detects serious genetic diseases like Down's syndrome in pregnancies at high risk, "the benefits of knowing the test results could outweigh the possible risk of hemangiomas or other abnormalities."
