title: Platelet aggregation in citrated whole blood of the first trimester of pregnancy.
abstract: BACKGROUND
  It was recently suggested that platelet reactivity is reduced in early pregnancy. This study was performed to determine whether the citrated whole blood from 33 pregnant women in their first trimester showed spontaneous platelet aggregation and whether it differed in extent from that of 11 non-pregnant women.
  
  
  METHODS
  The platelet count and number of platelet aggregates (PA) were serially determined in the same citrated whole blood specimens at 15, 30, 45, 60, 75, and 90min after blood sampling using a hematology analyzer.
  
  
  RESULTS
  The number of PA increased significantly at 30min and thereafter in both groups, but was consistently lower for pregnant than non-pregnant women over the 90-min observation period. The platelet count decreased significantly in a time-dependent manner in both groups, but was significantly lower at 30 and 90min for non-pregnant than pregnant women. The number of PA showed a significant positive correlation with net decrease in platelet count for both pregnant and non-pregnant women. PA counts were also significantly positively correlated with the mean platelet volume.
  
  
  CONCLUSIONS
  Platelet reactivity monitored by the increase in number of PA and the fall in platelet count was reduced in early pregnancy compared with non-pregnant healthy controls.
authors.affiliation: Department of Obstetrics, Hokkaido University Graduate School of Medicine, Sapporo Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Umazume
authors.affiliation: Department of Obstetrics, Hokkaido University Graduate School of Medicine, Sapporo Japan. Electronic address: taka0197@med.hokudai.ac.jp.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Yamada
authors.affiliation: Department of Obstetrics, Hokkaido University Graduate School of Medicine, Sapporo Japan.
authors.forename: Mamoru
authors.initials: M
authors.lastname: Morikawa
authors.affiliation: Department of Obstetrics, Hokkaido University Graduate School of Medicine, Sapporo Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Ishikawa
authors.affiliation: Department of Obstetrics, Hokkaido University Graduate School of Medicine, Sapporo Japan.
authors.forename: Itsuko
authors.initials: I
authors.lastname: Furuta
authors.affiliation: Department of Obstetrics, Hokkaido University Graduate School of Medicine, Sapporo Japan.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Koyama
authors.affiliation: Division of Laboratory and Transfusion Medicine, Hokkaido University Hospital, Sapporo Japan.
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Matsuno
authors.affiliation: Department of Obstetrics, Hokkaido University Graduate School of Medicine, Sapporo Japan.
authors.forename: Hisanori
authors.initials: H
authors.lastname: Minakami
mesh_terms: D000328:Adult; D019343:Citric Acid / Q000737:chemistry*; D005260:Female; D006801:Humans; D010974:Platelet Aggregation; D011247:Pregnancy; D011261:Pregnancy Trimester, First / Q000097:blood*
chemical_list: D019343:Citric Acid
keywords: Mean platelet volume; Platelet reactivity; Pregnancy; Spontaneous platelet aggregation; Venous thromboembolism