Amniocentesis, a test used to detect genetic abnormalities in a fetus, is not as risky as was previously believed, a new study suggests. The test, often giving to pregnant women over 35 or with a family history of genetic disorders, involves withdrawing amniotic fluid from the uterus with a needle. Many pregnant women are terrified of the test because studies in the 1970s and 1980s suggested that it would trigger miscarriage in one in 200 procedures. But a group of researchers from Mount Sinai School of Medicine in New York has reassessed the test’s miscarriage risk and found it eight times safer, with miscarriage triggered in only one of 1,600 procedures. The researchers looked at 35,003 women from 15 clinics, all between 10 and 14 weeks after conception. Roughly 3,100 underwent amniocentesis and 31,907 didn’t. The researchers, who could not explain why earlier research showed the procedure to be far more dangerous, found no significant difference between the number of miscarriages in the group that underwent amniocentesis and the group that didn’t.

BOTTOM LINE: “When doctors offer the test to patients, they should take into account the results of this study showing a lower miscarriage risk,” said Dr. Keith Eddleman, the study’s lead author.

CAUTIONS: This is the first study to show such a low miscarriage risk. More are required to confirm this finding.

WHAT’S NEXT: Eddleman wants to see whether the miscarriage risk associated with another procedure used to detect fetal genetic abnormalities – the chorionic villus sampling test – is also lower than suggested by previous studies.

WHERE TO FIND IT: Obstetrics & Gynecology, November

SENA DESAI GOPAL