title: Ultrastructural analysis of platelets during three phases of pregnancy: a qualitative and quantitative investigation.
abstract: OBJECTIVE
  In the past, platelet morphology during normal pregnancy has not been given much attention.
  
  
  METHODS
  Electron microscopy analysis of platelets from 60 pregnant individuals (30 early pregnancy (weeks 8-14) participants and 30 late pregnancy (weeks 36-40) participants which were followed up 6-8 weeks post-partum) were compared to platelets from 30 non-pregnant individuals as well as each other to establish whether differences in platelet morphology exist during pregnancy.
  
  
  RESULTS
  Ultrastructural changes pertaining to the external and internal arrangements of platelets were visible. Fixated platelets showed pseudopodia formation and membrane blebbing. Increased and enlarged open canalicular system pores, pseudopodia formation, platelet spreading, and membrane blebbing were visible in vital platelets. Platelets from pregnancy were tightly packed and internal structures were different from the non-pregnant group. The internal granules showed modification in their occurrence within the cell. The α- and lysosomal granule counts were significantly increased during pregnancy while dense granule and mitochondrial numbers were significantly decreased.
  
  
  CONCLUSIONS
  This may point to a pregnancy-specific modification. The changes in platelet ultrastructure discerned in this study attribute to the hypercoagulable state associated with pregnancy. All ultrastructural alterations associated with pregnancy persist for at least 2 months after birth.
authors.forename: Albe C
authors.initials: AC
authors.lastname: Swanepoel
authors.forename: Etheresia
authors.initials: E
authors.lastname: Pretorius
mesh_terms: D000293:Adolescent; D000328:Adult; D001792:Blood Platelets / Q000648:ultrastructure*; D005260:Female; D006801:Humans; D008855:Microscopy, Electron, Scanning / Q000379:methods*; D046529:Microscopy, Electron, Transmission / Q000379:methods*; D011247:Pregnancy / Q000097:blood*; D055815:Young Adult
keywords: Blood platelets; Morphology; Pregnancy; Scanning electron microscopy; Transmission electron microscopy