How common is Edwards syndrome (trisomy 18)?

How common is Edwards syndrome (trisomy 18)?

Edwards syndrome (trisomy 18) occurs in an estimated 1 out of every 5,000 to 6,000 live births. The condition is more common during pregnancy (1 out of every 2,500 pregnancies), but most (at least 95%) fetuses don’t survive full term due to complications from the diagnosis, so pregnancies can end in miscarriage or babies are stillborn.