Does a hemoglobin (Hb) electrophoresis result showing 58% hemoglobin A (HbA), 39% sickle cell hemoglobin (HbS), and a small amount of fetal hemoglobin (HbF) in a female of reproductive age with a potential history of sickle cell disease or trait indicate recent childbirth?

Hemoglobin Electrophoresis Interpretation: Sickle Cell Trait vs. Recent Childbirth

This hemoglobin electrophoresis pattern (58% HbA, 39% HbS, small amount HbF) indicates sickle cell trait (HbAS), not recent childbirth. The presence of fetal hemoglobin in this context is unrelated to pregnancy status and represents either persistent HbF commonly seen in individuals with sickle cell trait or a separate condition like hereditary persistence of fetal hemoglobin.

Understanding the Hemoglobin Pattern

The 58% HbA and 39% HbS ratio is diagnostic of sickle cell trait (heterozygous HbAS), not sickle cell disease. 1

• Sickle cell trait typically produces 55-65% normal HbA and 30-40% HbS, which matches this patient's pattern almost exactly 1
• In contrast, homozygous sickle cell disease (HbSS) results in 80-95% HbS with no normal HbA 1
• The presence of majority HbA definitively excludes sickle cell disease and confirms trait status 1

Fetal Hemoglobin: Not a Pregnancy Indicator

Fetal hemoglobin detected on adult hemoglobin electrophoresis has no relationship to recent childbirth or current pregnancy status. 2

• Fetal hemoglobin is produced by the fetus, not the mother, during pregnancy 3
• Maternal blood does not contain fetal hemoglobin from carrying a pregnancy 3
• HbF normally declines from 60-80% at birth to adult levels by 6-12 months of age in all individuals 2

Why This Patient Has Detectable HbF

Small amounts of fetal hemoglobin persist into adulthood in many individuals with sickle cell trait and disease, representing a normal variant. 4, 5

Several explanations exist for the "small amount" of HbF in this patient:

• Hereditary Persistence of Fetal Hemoglobin (HPFH): A benign genetic condition where HbF continues beyond infancy, often discovered incidentally during hemoglobinopathy screening 2
• Natural HbF variation in sickle cell trait: Individuals with HbAS commonly have slightly elevated HbF compared to those without hemoglobinopathies 5, 6
• Normal low-level HbF: Even healthy adults without hemoglobinopathies can have trace amounts of HbF (typically <1-2%) 2

Clinical Significance and Management

This patient has sickle cell trait, which is generally benign and requires genetic counseling rather than disease management. 1

• Sickle cell trait is asymptomatic under normal physiological conditions 1
• Symptoms only manifest under extreme conditions: severe dehydration, high altitude, or intense physical exertion 1
• The primary clinical importance is genetic counseling: this patient can pass the sickle cell gene to offspring 1
• If this patient has children with another carrier, there is a 25% chance of having a child with sickle cell disease 3

Common Pitfalls to Avoid

Do not confuse maternal hemoglobin electrophoresis with fetal hemoglobin levels measured during pregnancy monitoring. 3

• Fetal hemoglobin measurements in obstetric contexts refer to hemoglobin in the fetus's blood, obtained through cordocentesis or fetal blood sampling 3
• These are completely separate from maternal hemoglobin electrophoresis 3

Do not misdiagnose sickle cell trait as sickle cell disease based on the presence of HbS. 2

• The ratio of HbA to HbS is critical: majority HbA = trait; majority or exclusive HbS = disease 1
• Misdiagnosis can lead to unnecessary anxiety and inappropriate management 2