The Ratios of Total Serum Protein to Protein Electrophoretic Fractions during Pregnancy as Diagnostic Information

Research Article

J Dis Markers. 2021; 6(2): 1045.

The Ratios of Total Serum Protein to Protein Electrophoretic Fractions during Pregnancy as Diagnostic Information

Lisowska-Myjak B¹*, Skarżyńska E¹, Zborowska H², Strawa A¹ and Jakimiuk A³

¹Department of Biochemistry and Clinical Chemistry, Medical University of Warsaw, Poland

²Department of Laboratory Diagnostics, Medical University of Warsaw, Poland

³Department of Reproductive Health, Institute of Mother and Child and Department of Obstetrics and Gynecology, Central Clinical Hospital of the Ministry of the Interior and Administration, Warsaw, Poland

*Corresponding author: Barbara Lisowska-Myjak, Department of Biochemistry and Clinical Chemistry, Medical University of Warsaw, ul. Banacha 1, 02-097 Warsaw, Poland

Received: July 30, 2021; Accepted: October 27, 2021; Published: November 03, 2021


Background: Ratios of total serum protein (TP) concentrations to serum protein electrophoretic fractions could reflect impact on intravascular homeostasis in pregnancy of qualitative and quantitative changes in highabundance protein of serum between consecutive trimesters.

Methods: TP concentrations were measured by biuret method and six protein fractions were separated by electrophoresis in 186 serum samples from 65 healthy pregnant women in each trimester of normal singleton pregnancy and from 20 non-pregnant women.

Results: TP/fraction ratios in pregnancy and postpartum period differed from those in non-pregnancy. Ratios of TP/ protein fractions changed across trimesters, mostly between first and second trimesters with increase in TP / albumin ratio by 5% while ratios TP/alpha-1-, TP/alpha-2- and TP/beta-1- globulin decreased by 22%, 15% and 15%, respectively. TP/gamma-globulin ratio increased by 15% between second and third trimesters.

Conclusions: Ratios of TP concentrations to specific protein fractions may reflect trimester-specific qualitative and quantitative changes in serum content of high-abundance proteins and their effect on serum protein homeostasis in pregnancy. Decreased ratios of TP to alpha-1-, alpha-2-, beta-1- and beta-2- globulins confirm increases in concentrations of individual proteins contained in these fractions with development of pregnancy, with largest increase in level of alpha-1-globulin in earliest period of pregnancy.

Keywords: Biomarkers; Electrophoresis; Pregnancy; Serum proteins; Serum protein profile


NP: Non Pregnant; PP: Postpartum; TP: Total Protein; TP/ Protein Fraction Ratio: Total Protein/Protein Fraction Ratio


To date, there are very few specific diagnostic markers that could be used for evaluating complex metabolic processes during pregnancy and predicting their possible effect(s) on postnatal development. Serum protein patterns determined throughout pregnancy seem to offer such valuable biomarkers obtained noninvasively which could aid in differentiating between normal physiological changes and disease pathology in pregnancy.

Each electrophoretically separated serum fraction is characterized by the concentration range for the protein associated with the fraction and the composition of a group of individual proteins with similar electrophoretic mobility, but independently involved in different metabolic processes [1-5]. Protein classification by serum protein electrophoresis is performed for the most abundant twenty-two wellcharacterized proteins, which account for 99% of the human serum proteome, while the proteins constituting the remaining 1% are difficult to separate electrophoretically and identify due to their very low serum concentrations and a tendency to bind to other proteins [6-8].

Establishing the association between electrophoretic serum protein fractions and serum TP levels in the three trimesters of pregnancy and the postpartum period may help in better understanding of the involvement of individual protein fractions in the maintenance of protein homeostasis during pregnancy [9]. Identification of these protein fractions whose serum concentrations undergo considerable quantitative changes during pregnancy altering their relation to TP may provide preliminary information on their role(s) in specific metabolic processes at various periods of gestation. The ratios of TP to specific electrophoretic protein fractions (TP/ protein fraction ratio) might be used throughout gestation as a screening test to identify the qualitative and quantitative changes in the composition of high-abundance proteins in the serum of pregnant women and serve as diagnostic biomarkers of maternal disease and fetal pathology.

The purpose of the study was to assess the TP/protein fraction ratios in the serum of pregnant women, measured trimester by trimester and in the postpartum period (24-48 h after delivery), compared to the concentrations in the sera of non-pregnant controls.

Material and Methods


Prospectively screened 64 healthy women aged 17-43 years (mean ± SD: 31.4 ± 5.8) attending three routine antenatal visits in each trimester of a normal singleton pregnancy: first trimester, pregnancy weeks 8-12 (n=55); second trimester, pregnancy weeks 20-24 (n= 42); third trimester, pregnancy weeks 34-38 (n=39); the postpartum period, 24-48 h after delivery (n=30). The differences in the concentration of the parameters in the serum were statistically assessed between the groups representing subsequent stages of pregnancy. From among 64 examined women, 15 participants were selected, whose blood samples were obtained in each trimester of pregnancy and in the postpartum period (four samples from each woman) and graphically illustrated the dynamics of changes in the examined parameters during pregnancy (Figure 1).