An evaluation of the ability of leucocyte depletion filters to remove components of amniotic fluid.

Haemorrhage remains an important cause of maternal mortality worldwide. Cell salvage carries a theoretical risk of amniotic fluid embolus syndrome and is too expensive for use in many parts of the world. To explore cheaper options, we investigated whether a leucocyte depletion filter alone removes components of pure amniotic fluid. Amniotic fluid was collected from 10 women during elective caesarean section and passed through a LeukoGuard® RS filter. Pre- and post-filtration samples were compared in the laboratory. Lamellar bodies and fetal squames were almost completely removed (filtration efficacy 96.6% and 99.9%, respectively; p<0.0001 and <0.0004), and hair was completely removed (p=0.002). Filtration had no effect on concentrations of α-fetoprotein, tissue factor or endothelin-1, or on the presence of meconium or vernix. Additional work is required to evaluate whether cell salvage using filtration alone may be useful in maternal haemorrhage in the developing world.