Carrier screening utilization varies among clinicians including obstetricians (ObGyns), maternal fetal medicine specialists (MFMs) and reproductive endocrinologists (REIs). ACOG currently recommends universal screening for cystic fibrosis and spinal muscular atrophy, and ethnicity-based screening when appropriate. ACOG acknowledges that expanded carrier screening (ECS) has many benefits, however, advises that if ordered, ECS panels should only include high impact disorders (severe, prevalent and well-understood). Our laboratory offers screening for up to 301 genes. These genes are available in pre-curated panels (3, 46, or 288 genes), or they can be ordered as single tests/customized panels. Thirteen additional genes (common, variable, and/or adult onset) are available as an add-on to any panel.
Carrier screening was performed by next-generation sequencing with deletion and duplication analysis for up to 301 genes. Ordering patterns by clinician type was assessed.
Over thirteen months, 35,390 patient samples from 2,540 clinicians were tested. The majority of orders came from REIs (37%) and ObGyns (30%). Fifty-six percent of all orders exceeded ACOG ECS guidelines (≥288 genes). Guideline-based testing accounted for 20% of orders, with ObGyns having the highest adherence to guideline-based ordering (27%).
Despite current ACOG criteria, our data shows that more than half of carrier orders exceed ECS recommendations, even including frequent/variable disorders. Many factors, including patient preference, insurance coverage and cost impact carrier screening utilization. More specific guidelines may lead to more consistent testing across clinicians and influence patient and insurance decision factors.