Tissue polypeptide specific antigen and soluble Fas during normal pregnancy and early life

Intrauterine fetal development is characterized by increased rates of proliferation and apoptosis, while both these processes may be attenuated post-natally.

Tissue polypeptide specific antigen and sFas serum concentrations were determined during pregnancy and post-natally, in order to evaluate their alterations during these crucial periods.

Forty-seven healthy pregnant women, their full-term newborns and 35 healthy adults (controls) were included in the study. Markers were measured: (a) in maternal serum (MS), during the 1st, 2nd, 3rd trimester and at the 1st stage of labor; (b) in the umbilical cord (UC), during the 2nd stage of labor; (c) in neonatal serum in the 1st (IN) and 5th (5N) day after birth; and (d) in controls.

The serum TPS concentrations in MS increased significantly with gestational age, being higher in the 3rd trimester and labor, than those in controls (p < 0.001). TPS values were significantly lower in the UC, compared to those in MS (p < 0.001), while they were markedly elevated in IN, compared to MS and UC (p < 0.001), and subsequently decreased in 5N (p < 0.001), remaining higher, than those in the controls (p < 0.001). Serum sFas concentrations in the MS depended significantly on gestational age (p < 0.001), being significantly lower in the first trimester, than those in the second (p < 0.003), the third (p < 0.03), in labor and controls (p < 0.005). sFas concentrations in the UC were significantly lower than in MS and controls (p < 0.001), while they increased significantly in 5N samples (p < 0.01).

Our results demonstrate: (a) a higher apoptosis rate in the first trimester of pregnancy, possibly affecting maternal immuno-tolerance, followed by a down-regulation during the post-natal period; (b) a progressively increased proliferation from the first trimester to parturition, reflecting the fetal and placental growth and development, that seems to be thereafter moderated.