Clearance of fetal products and subsequent immunoreactivity of blood salvaged at cesarean delivery

Objective: To determine if fetal products can be detected after post placental, intraoperative blood salvage, and if the product is immunoreactive with maternal serum. Methods: We suctioned the shed blood of 27 term gravidas with intact membranes who had cesareans, beginning 4 minutes after placenta removal, into a COPE BRAT-2(TM) salvage system (COBE Cardiovascular, Arvada, CO). Preoperative maternal and fetal cord blood samples were collected. preprocessing and postprocessing salvaged blood was analyzed for alpha-fetoprotein (AFP), hemoglobin, hematocrit, and plasma-free hemoglobin. Papanicolaou smears and immunodiffusion using Ouchterlony methods for detection of protein-protein interactions were run on maternal serum. Postprocess salvaged blood was subjected to Kleihauer-Bethke tests, typed, and crossmatched with maternal serum, including mixed fields. No women were transfused. Results: Ten of 27 women shed enough postprocess salvaged blood for analysis. Alpha-fetoprotein was cleared, but Kleihauer-Bethke analyses were positive in all postprocessing specimens. Anucleate squamous cells were detected by Papanicolaou smears in four of ten preprocessed specimens, with one cleared by processing. No antigen-antibody reaction between maternal and preprocessed or postprocessed salvaged blood was found by the Ouchterlony method. Crossmatching of the final product with maternal serum was successful, with negative mixed fields in all cases. Conclusion: Fetal debris was present in blood salvaged 4 minutes after removal of placenta. Despite clearance of humoral material, fetal blood cells were detectable in all postprocess salvaged blood. The product was compatible with maternal blood by crossmatching and its supernate did not immunoreactive with maternal serum. (Obstet Gynecol 1999;93:968-72. (C) 1999 by The American College of Obstetricians and Gynecologists.)