Challenging the Strategy of Maternal Age–Based Prenatal Genetic Counseling

Abstract

THE DECISION TO OFFER PREGNANT WOMEN PRENATAL diagnosis for genetic diseases has long had an agebased trigger. Early studies convincingly demonstrated an escalating rate of aneuploidy with advancing maternal age, but risks related to amniocentesis are independent of maternal age. When the flat risk-line from the invasive diagnostic procedure (iatrogenic pregnancy loss) crossed the age-related ascending risk-line of aneuploidy on a graph of adverse events, an intersection was determined that became the age standard for offering the procedure. Data from the 1970s appeared to suggest that at the age of 35 years a woman had a similar chance of delivering a child with aneuploidy as experiencing a miscarriage after an amniocentesis, and that age became “the” prompt for genetic counseling. Much has been learned since then, but despite the substantially increased efficiency of diagnostic technologies and possibly reduced risks of procedure-related pregnancy loss, the recommendation remains unchanged. According to the current guidelines of the American College of Obstetricians and Gynecologists, “Women with singleton pregnancies who will be age 35 years or older at delivery should be offered prenatal diagnosis.” We suggest that advances in science and careful consideration of the ethics of testing should undermine any residual support for that standard.