Biologic Tests for the Diagnosis of Amniotic Fluid Embolism

Amniotic fluid embolism is a rare, unpredictable and often lethal complication of pregnancy and childbirth. Because of its variable presentation, an early biologic test would help to establish the diagnosis. We investigated in maternal serum 4 components of amniotic fluid, i.e., alpha-fetoprotein (AFP), l'insuline like growth factor binding protein-1 (IGFBP-1), fetal fibronectin (fFN) and placental alpha 1-microglobulin (PAMG-1). On the 6 cesareans controls involved, none of the makers increased after membranes section. PAMG-1 is unsuitable because its detection is always positive or doubtful even in the baseline. On the 7 cases suspected of amniotic fluid embolism, no detectable increase in any of those markers was noted in 3 cases, which is not in favour of this diagnosis. In the remaining cases, IGFBP-1 and fFN became detectable, confirming histological evidences of amniotic fluid embolism in 2 cases. The follow up of those markers in maternal blood confirmed the suspicion of amniotic fluid embolism at 21 wg in one case of ongoing pregnancy. These preliminary results point out the potential interest to assay maternal serum AFP, IGFBP-1 and fFN to confirm amniotic fluid embolism using rapid laboratory tests.