(1172) Implementation of genetic carrier screening in the OB population: Guideline recommendation adherence

The increased availability of genetic testing has raised concerns regarding its appropriate ordering. To guide providers, the American College of Obstetrics and Gynecology (ACOG), develop practice guidelines. ACOG recommends offering carrier screening for cystic fibrosis (CF) and more recently, spinal muscular atrophy (SMA), to all pregnant people. This study determined adherence to ACOG’s carrier screening guidelines in a large obstetric population in Texas.

Study Design:

A month-long retrospective chart review in an academic institution was conducted. The cohort was obtained by reviewing ultrasound and genetic counseling schedules. Descriptive statistics were used to characterize data.

Results:

Of the 500 charts reviewed, 314 patients had carrier screening for at least one condition. Carrier screening was ordered by their obstetrician (OB) (n=249), a genetic counselor (n=39), or by both (n=26). The type of carrier screening varied (sequencing versus genotyping) and included many combinations (CF only, CF and SMA; CF, SMA, and hemoglobinopathies; expanded carrier screening [ECS]). The majority of patients in the GC group (85%) had ECS which includes testing for CF and SMA. In the OB group, the test most ordered was hemoglobin electrophoresis (36%). The most ordered test combination in the OB group was CF and hemoglobin electrophoresis (27%). The least ordered test in the OB group was SMA – either by itself (1.1%), in combination with CF (1.4%), or in combination with both CF and hemoglobin electrophoresis (3.3%). ACOG carrier screening guideline adherence in the GC group was 97%. Guideline adherence in the OB group was 31%.

Conclusion:

The majority of OB patients in our population did not receive ACOG recommended carrier screening, as testing for SMA was only ordered in 31% of cases. Patients were more likely to be screened for guideline recommended conditions when ordered as part of ECS panels. Expanded provider education regarding the implementation of genetic carrier screening in the OB population is warranted to ensure best practices.