Hemoglobinopathy screening in pregnancy: comparison of two protocols

Area of Science:

• Obstetrics and Gynecology
• Hematology
• Clinical Diagnostics

Background:

• Hemoglobinopathies pose risks during pregnancy.
• Accurate screening is crucial for identifying affected pregnancies.
• Existing screening protocols vary in effectiveness and cost.

Purpose of the Study:

• To evaluate a hemoglobinopathy screening protocol using sickle solubility testing and red blood cell (RBC) indices.
• To determine the protocol's ability to identify pregnancies at risk for hemoglobinopathies.
• To compare the cost-effectiveness of selective versus universal hemoglobin electrophoresis.

Main Methods:

• Retrospective chart review of prenatal patients at New York Hospital/Cornell Medical Center in 1996.
• Comparison of RBC indices with hemoglobin electrophoresis results.
• Analysis of screening protocol sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV).
• Statistical analysis using Student's t-test.

Main Results:

• 36 carriers of hemoglobinopathy traits were identified among 631 patients (5.7%).
• Four carriers had normal RBC indices and would have potentially been missed by sickle solubility testing.
• A selective hemoglobin electrophoresis protocol demonstrated high sensitivity (88.9%) and negative predictive value (99.2%).
• The selective protocol was estimated to be $18/patient less expensive.

Conclusions:

• A screening protocol combining sickle solubility testing and RBC indices is a valuable tool for identifying at-risk pregnancies.
• While not identifying every carrier, this selective approach is cost-effective.
• The protocol may be suitable for specific populations, balancing detection rates with economic considerations.