HIGH POLYUNSATURATED FATTY-ACID, THROMBOXANE A(2), AND ALPHA-FETOPROTEIN CONCENTRATIONS AT THE HUMAN FETOMATERNAL INTERFACE

Polyunsaturated fatty acids (PUFA) like arachidonic (C20:4) and docosa hexaenoic (C22:6) acids are essential for harmonious fetal development . This study evaluates, at near term, the distributions of free fatty acids (FFA) and their fetal carrier protein, alpha-fetoprotein (AFP) i n the maternal (M) and fetal circulation (umbilical arteries (A) and v ein (V)), focusing on the fete-maternal interface where maternal inter villous blood (I) contacts the fetal trophoblast. FFA concentrations i n intervillous and maternal blood were similar, while those in umbilic al arteries and vein were 2- to 4-fold lower (P<0.001). There were mor e saturated FFA in umbilical vein (41%) and arteries (44%) blood than in maternal (30%) and intervillous (32%) blood (P<0.001). Monounsatura ted FFA predominated (P<0.001) in maternal (43%) blood, but not in int ervillous (35%), umbilical vein (33%) and arteries (31%) blood. Di-tri unsaturated FFA were similar in intervillous and maternal (25%) blood and lower in umbilical vein and arteries (16%) blood (P<0.001). PUFA w ere low in maternal (2.5%) blood and higher in intervillous and umbili cal vein and arteries (9%, P<0.001); consequently, C20:4 (40 mu M) and C22:6 (16 mu M) were the most abundant in the intervillous space. The AFP concentrations and AFP lectin-reactive isoforms were similar in i ntervillous and umbilical vein and arteries blood, but immuno-electrop horesis revealed a particular AFP conformation (less immune-reactive, more anionic) in the intervillous space, suggesting that AFP is heavil y loaded with PUFA at the feto-maternal interface. Prostacyclin derive d from C20:4 was similar in all compartments but the thromboxane A, co ncentration was 10-fold higher in intervillous blood than in maternal and umbilical vein and arteries blood. Thus the feto-maternal interfac e has a specific pattern of cell signalling molecules that might criti cally influence parturition.