Reference values for serum components in pregnant women.

Area of Science:

• Biochemistry
• Clinical Chemistry
• Obstetrics

Background:

• Establishing reference ranges for blood serum components during pregnancy is crucial for accurate clinical interpretation.
• Physiological changes during pregnancy can significantly impact biochemical markers.

Purpose of the Study:

• To determine reference intervals for 11 chemical blood serum components in healthy pregnant women across three trimesters.
• To identify specific biochemical markers that undergo significant alterations during pregnancy.

Main Methods:

• Collection of blood serum samples from 100 healthy pregnant women.
• Analysis of 11 chemical components, with results presented as 2.5, 50, and 97.5 percentiles.
• Comparison of values across the first, second, and third trimesters.

Main Results:

• Significant changes noted in Serum Albumin (S-Albumin), Serum Alkaline Phosphatase (S-Alkaline phosphatase), and Serum 5'-Nucleotidase (S-5'-Nucleotidase), especially in the third trimester.
• Serum Sodium (S-Na) showed a significant decrease starting in the first trimester.
• Serum Calcium (S-Ca) levels decreased in parallel with S-Albumin; corrected calcium levels showed smaller changes.
• Serum Potassium (S-K), Serum Bilirubin (S-Bilirubin), and Thymol Turbidity Test values remained stable throughout pregnancy.
• Serum Gammaglutamyl-transferase (S-Gammaglutamyl-transferase), Serum Aspartate Aminotransferase (S-Aspartate aminotransferase), and Serum Alanine Aminotransferase (S-Alanine amino-transferase) showed no significant mean changes, though enzyme distributions skewed in the third trimester.

Conclusions:

• Pregnancy induces specific, trimester-dependent alterations in several blood serum analytes.
• Reference intervals for certain biochemical markers need to be trimester-specific for pregnant women.
• Monitoring S-Albumin, S-Alkaline phosphatase, S-5'-Nucleotidase, and S-Na is important during pregnancy, particularly in the third trimester.