Amnio Recommended at 40, Not 35

Advanced maternal age. It’s a moniker that used to be written into the chart of every woman after the age of 35. For many women, it meant considering amniocentesis and its accompanying risk of miscarriage or premature delivery. That recommendation, a new study says, no longer has to be made until the expectant mother reaches the age of 40.

The Journal of Obstetrics and Gynecology Canada says that maternal age should be a factor in considering amnio only when the pregnant woman reaches the age 40. An earlier American study said that the risk of miscarriage following an amnio was 1 in 1600. This study says the risks were miscalculated and are more likely to be 1 in 300.

Amniocentesis is a prenatal diagnostic test in which the amniotic sac is punctured with a small need so a genetic sample can be taken. Since the risk of conceiving a child with Downs syndrome increases after the mother reaches the age of 35, amnio became routine for women of “advanced maternal age” often even when markers for Downs syndrome weren’t seen on other diagnostic tests like ultrasound.