Level of S100B protein expression in the amnion at various gestational ages in the third trimester of normal pregnancies.

Background: S100B protein is a unique calcium-binding protein. Its biological role within the cell populations is not completely defined. Some pathological conditions that develop during pregnancy could affect S100B concentrations in the amniotic fluid, cord blood, and maternal serum. The aim of our study was to assess the correlation between S100B protein expression in the amnion, amniotic fluid and gestational age in the third trimester of uncomplicated pregnancies.

Methods: Amnion, amniotic fluid, maternal peripheral and umbilical cord blood samples were collected from healthy women who delivered at 31-36 weeks (n=17), 37-40 weeks (n=22), and 41-42 weeks (n=21). The expression of S100B in the amnion was assessed by immunohistochemistry and real-time (RT)-PCR, and its concentrations in amniotic fluid, maternal and cord blood sera were determined by ELISA.

Results: The S100B protein expression in the amnion and its concentrations in amniotic fluid, maternal and cord blood sera of patients in the third trimester were not significantly different at various gestational ages.

Conclusions: The S100B protein expression in the amnion and the S100B protein concentrations in amniotic fluid, maternal and cord blood do not vary significantly in the third trimester of uncomplicated pregnancies.