It is not cost effective to screen for spinal muscular atrophy, according to a study to be presented today at the Society for Maternal-Fetal Medicine's (SMFM) annual meeting, The Pregnancy Meeting ™, in Chicago.

Spinal muscular atrophy (SMA) is the most common genetic cause of infant mortality and the second most common inherited autosomal recessive disorder. There is controversy about whether prenatal carrier detection should be routinely offered to couples. In the November 2008 issue of the Genetics in Medicine Journal, the American College of Medical Genetics recommended that carrier screening for SMA should be made available to all families. However, the American College of Obstetricians and Gynecologists, in a committee opinion from May 2009, recommended against preconception and prenatal screening in the general population.

In the study presented at the Society for Maternal-Fetal Medicine's meeting, researchers describe the analytic model that was created to compare a policy of universal prenatal SMA screening to that of no screening. Baseline assumptions included a disease prevalence of 1 in 10,000 for a carrier rate of 1 in 50 with 70% of affected children having severe disease. They assumed a 90% sensitivity rate for carrier screening and that 2% of SMA cases arise from de novo mutations. Baseline cost estimates (2009 dollars) included $400 for a carrier screen and $260,000 for the lifetime cost of a child with severe disease. Maternal quality-adjusted life-years (QALYs) were calculated assuming a 22% reduction in quality of life for having a child with severe disease and 8% for fetal loss.