The level of maternal immune tolerance and fetal maturity.

OBJECTIVES: Fetal maturity does not seem to be directly connected with the phenomenon of immune tolerance during pregnancy although the fetal maturation influences the process of initiation of the labor at term finishing the immune tolerance during pregnancy. CAP and RCAS1 are expressed by the trophoblast cells and afterwards by the placenta, these proteins are able to modulate the maternal immune response.

MATERIALS AND METHODS: 160 patients were randomly selected to our study. The patients were divided into two groups using K score according to the newborn's maturity: maturated and not fully maturated. Within the groups of matured and not fully matured newborns the subgroups were selected according to the type of the labor: spontaneous or induced. The oxytocinase plasma activity was established in plasma samples obtained from pregnant women a few days before delivery. The placental RCAS1 relative amount was assessed by Western blot analysis.

RESULTS: The differences in oxytocinase plasma level with respect to the fetal maturity were identified in our study however no RCAS1 expression changes were found regarding the fetal maturation. We determined the alterations in RCAS1 expression with respect to the occurrence of clinical symptoms of the spontaneous beginning of the labor in maturated and not-fully maturated groups of newborns.

CONCLUSIONS: Oxytocinase seems to be a useful marker of normal fetal development. The assessment of RCAS1 in placenta directly after delivery appears to indicate the level of maternal immune tolerance during the labor initiation. The level of the immune tolerance at the moment of the delivery drops independently of the fetal maturity.