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Fetal Loss Uncommon After Chorionic Villus Sampling

Posted to the Web: Wednesday, October 01 , 2008
NEW YORK (Reuters Health) Oct 01 - Chorionic villus sampling does not appear to raise the risk of fetal loss. Specifically, investigators at the Washington University School of Medicine in St. Louis found that the fetal loss rate following chorionic villus sampling was no different than the rate among pregnant women who did not undergo an invasive procedure, according to the results of a 16-year retrospective study.

"With the recent recommendations for screening for chromosomal abnormalities... demands for prenatal diagnosis are expected to increase," the researchers write in the October issue of Obstetrics & Gynecology. "Providing reliable information on the fetal loss rate and potential risk factors for fetal loss is important during counseling before undergoing an invasive procedure."

Using information from their institution's prenatal diagnosis database for all pregnant women seen between 1990 and 2006, Dr. Anthony O. Odibo and colleagues compared the fetal loss rate before 24 weeks gestation in patients who underwent chorionic villus sampling to that of patients who did not have any invasive procedure and had a live fetus documented on ultrasound between 10 and 14 weeks.

The fetal loss rates among the 5148 women who had chorionic villus sampling and the 4803 women who had no procedure were 2.7% and 3.3%, respectively, a nonsignificant difference.

Risk factors for fetal loss after chorionic villus sampling included African-American maternal race, two or more aspirations or needle insertions, heavy bleeding during the procedure, maternal age younger than 25 years, and gestational age at the time of chorionic villus sampling of less than 10 weeks.

However, the "final model only had a modest ability to discriminate between those at risk for fetal loss from those who will not lose the pregnancy," Dr. Odibo's team reports.

"This information will be useful in counseling patients considering this method of prenatal diagnosis," they conclude.

Obstet Gynecol 2008;112:813-819.