title: Decreased factor XII activity is associated with recurrent IVF-ET failure.
abstract: OBJECTIVE
  A decrease in factor XII (FXII) activity has been observed in women with unexplained recurrent miscarriages. Because of the many similarities between recurrent in vitro fertilization-embryo transfer (IVF-ET) failure and early pregnancy loss patients, we investigated whether women with recurrent IVF-ET failure had low FXII activity.
  
  
  METHODS
  Blood from 110 patients with three or more IVF-ET failures was tested for FXII activity, autoantibodies and other coagulation parameters. These patients were compared with 191 recurrent miscarriage patients, 87 controls. FXII activity was measured by an activated partial thromboplastin time (APTT) assay.
  
  
  RESULTS
  Factor XII activity of the IVF-ET failure group (median 79.5, range 37-150) was significantly lower than that of control group (median 109, range 35-225, P < 0.001 by Mann-Whitney test) or that of recurrent pregnancy loss (RPL) group (median 92, range 20-205). The FXII activity of IVF-ET failure patients was positively correlated with age, but not associated with the number of IVF-ET failures, infertile duration, autoantibodies, or other coagulation parameters.
  
  
  CONCLUSIONS
  Decreased FXII activity may causally relate to reproductive failure.
authors.affiliation: Department of Obstetrics and Gynecology, Specialized Clinical Science, Tokai University School of Medicine, Tokyo, Japan. hide-m@is.icc.u-tokai.ac.jp
authors.forename: Hidehiko
authors.initials: H
authors.lastname: Matsubayashi
authors.forename: Toshitaka
authors.initials: T
authors.lastname: Sugi
authors.forename: Takahiro
authors.initials: T
authors.lastname: Suzuki
authors.forename: Noa
authors.initials: N
authors.lastname: Uchida
authors.forename: Haruyo
authors.initials: H
authors.lastname: Atsumi
authors.forename: Shun-ichiro
authors.initials: S
authors.lastname: Izumi
authors.forename: Mikio
authors.initials: M
authors.lastname: Mikami
mesh_terms: D000026:Abortion, Habitual / Q000097:blood / Q000209:etiology*; D000328:Adult; D000367:Age Factors; D001323:Autoantibodies / Q000097:blood; D004624:Embryo Transfer; D005175:Factor XII Deficiency / Q000150:complications*; D005260:Female; D005307:Fertilization in Vitro; D006801:Humans; D008875:Middle Aged; D010314:Partial Thromboplastin Time; D017211:Treatment Failure
chemical_list: D001323:Autoantibodies