Soluble HLA-G changes in maternal blood serum during the progression of labor

The expression of the HLA-G antigen from implantation toward term is crucial for the growth of a semiallogenic fetus as it shields this fetus from the maternal cytotoxic response. Little is known, however, about the potential role of soluble HLA-G isoforms during delivery. The initiation of labor is associated with a complex molecular response leading to a brief activation of the maternal immune system with an accompanying capacity to restrict this activation, and HLA-G seems to be an important factor in enabling the proper immune response at the maternal fetal interface.

In our study the levels of soluble HLA-G concentration were evaluated in the blood serum samples obtained from 47 pregnant women who either underwent cesarean sections or delivered vaginally. The patients were divided into three subgroups according to the progression of labor at the time of the cesarean or, in cases of vaginal delivery, according to the duration of the pregnancy.

We have observed that the progression of labor is associated with a continuous increase in the sHLA-G plasma level. The sHLA-G levels were statistically significantly higher in the blood sera obtained from the women in advanced labor than from the women who were at the beginning of labor.

The changes in sHLA-G concentration levels observed during the stages of labor may indicate that this isoform participates in maintaining reproductive tract homeostasis.