title: Occult fetomaternal hemorrhage in women with pathological placenta with respect to permeability.
abstract: OBJECTIVE
  Women with pre-eclampsia (PE), placenta previa (PP), placental abruption (PA), and placental mesenchymal dysplasia (PMD) have been described as having placental permeability dysfunction. This study was performed to determine whether occult fetomaternal hemorrhage (FMH) is common in women with such complications and in women with non-reassuring fetal status.
  
  
  METHODS
  Forty-one antenatal and 39 postnatal blood samples were obtained from 46 women, including 11 with placental permeability dysfunction (5, 3, 2, and 1 with PE, PP, PA, and PMD, respectively) and 35 controls without such complications. To estimate the amount of fetal red blood cells, flow cytometry was performed using the fetal cell count system with two antibodies against fetal hemoglobin and carbonic anhydrase and the β-γ system with two monoclonal antibodies against hemoglobin β-chain and hemoglobin γ-chain. A diagnosis of FMH was made when the fraction size of the isolated cell population on scatter plots expressing fetal hemoglobin alone or hemoglobin γ-chain alone accounted for ≥0.02% of the total cell population on scatter plots.
  
  
  RESULTS
  FMH was identified in five women, including one each with PE, PA, PP, PMD, and no complications. Thus, the prevalence rate of FMH was significantly higher in women with complications than in controls (36% [4/11] vs 2.9% [1/35], respectively, P =  0.009). The FMH occurrence rate did not differ between women with and without non-reassuring fetal status (7.7% [1/13] vs 12% [4/33], respectively, P =  1.000).
  
  
  CONCLUSIONS
  The risk of fetal red blood cells trafficking into the maternal circulation may be increased in women complicated with PE, PA, PP, and PMD.
authors.affiliation: Department of Perinatal Medicine, Hokkaido University Hospital, Sapporo, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Umazume
authors.affiliation: Department of Perinatal Medicine, Hokkaido University Hospital, Sapporo, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Yamada
authors.affiliation: Department of Perinatal Medicine, Hokkaido University Hospital, Sapporo, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Morikawa
authors.affiliation: Department of Perinatal Medicine, Hokkaido University Hospital, Sapporo, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Ishikawa
authors.affiliation: Department of Perinatal Medicine, Hokkaido University Hospital, Sapporo, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Kojima
authors.affiliation: Department of Perinatal Medicine, Hokkaido University Hospital, Sapporo, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Cho
authors.affiliation: Department of Medical Laboratory Science, Faculty of Health Sciences, Hokkaido University, Sapporo, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Masauzi
authors.affiliation: Department of Perinatal Medicine, Hokkaido University Hospital, Sapporo, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Minakami
mesh_terms: D000037:Abruptio Placentae / Q000097:blood / Q000453:epidemiology; D000328:Adult; D005260:Female; D005312:Fetal Blood; D005331:Fetomaternal Transfusion / Q000150:complications / Q000453:epidemiology*; D006801:Humans; D010539:Permeability; D010922:Placenta Diseases / Q000097:blood* / Q000453:epidemiology*; D010923:Placenta Previa / Q000097:blood / Q000453:epidemiology; D011225:Pre-Eclampsia / Q000097:blood / Q000453:epidemiology; D011247:Pregnancy; D011256:Pregnancy Outcome
keywords: alpha-fetoprotein; fetomaternal hemorrhage; placenta previa; placental mesenchymal dysplasia; pre-eclampsia