Haptoglobin in pregnancy: Trimester-specific reference intervals.

Area of Science:

• Clinical Chemistry
• Reproductive Medicine
• Hematology

Background:

• Physiologic changes during pregnancy can alter serologic markers.
• Lower haptoglobin values in pregnancy may be mistaken for hemolysis.

Purpose of the Study:

• To determine trimester-specific reference intervals (RIs) for haptoglobin during pregnancy.
• To investigate potential misdiagnosis of hemolysis due to pregnancy-related haptoglobin variations.

Main Methods:

• A quality improvement project analyzed 401 serum samples from pregnant patients.
• Haptoglobin levels were measured using Roche Cobas 8000 systems.
• Statistical comparison of haptoglobin between trimesters was performed using the Mann-Whitney test.

Main Results:

• Nonparametric RIs for haptoglobin were established for each trimester.
• A significant difference in haptoglobin distribution was observed in the second trimester (median, 98 mg/dL) compared to the first (median, 113.5 mg/dL) and third (median, 112.5 mg/dL) trimesters.

Conclusions:

• While overall pregnancy haptoglobin RIs align with nonpregnant populations, a significant dip occurs in the second trimester.
• Lower second-trimester haptoglobin may lead to misdiagnosis of intravascular hemolysis.
• Trimester-specific RIs are crucial for accurate interpretation of haptoglobin levels in pregnant individuals.