title: Maternal serum total activin A and follistatin in pregnancy and parturition.
abstract: OBJECTIVE
  To examine changes in maternal serum levels of activin A and follistatin during pregnancy and labour.
  
  
  METHODS
  In three cross sectional and three longitudinal studies venous blood was collected from women during pregnancy, spontaneous labour, labour induction and prior to elective caesarean section for the measurement of activin A and follistatin.
  
  
  METHODS
  Monash Medical Centre, Clayton, Victoria, Australia.
  
  
  METHODS
  One hundred and twenty-three women participated in a cross sectional study in pregnancy, 18 women in two longitudinal pregnancy studies, 36 women in a cross sectional labour study, nine women in a longitudinal study of labour induction. Ten women undergoing elective caesarean section were also studied.
  
  
  METHODS
  Activin A and follistatin were measured using two sensitive and specific enzyme-linked immunosorbent assays.
  
  
  RESULTS
  In the cross sectional study of pregnancy, mean (SEM) maternal serum activin A and follistatin levels increased towards term (2.4 ng/mL (0.3) and 1.8 ng/mL (0.3) in first trimester to 18.9 ng/mL (3.8) and 5.3 ng/mL (0.9) at term, respectively), but the longitudinal study revealed that levels plateau in the last three weeks of pregnancy (16.0 ng/mL (2.6) and 6.2 ng/mL (1.4) at 37 weeks and 16.6 ng/mL (3.5) and 6.2 ng/mL (0.5) before labour for activin A and follistatin, respectively). There was no difference in levels of activin A and follistatin between women delivered by caesarean section and labouring women at term (14.9 ng/mL (2.8) vs 11.0 ng/mL (0.93) and 5.95 ng/mL (0.67) vs 5.71 ng/mL (0.63), respectively) and levels of both proteins did not alter throughout spontaneous or induced labour.
  
  
  CONCLUSIONS
  We believe that these data argue against activin A playing an acute role in the initiation or regulation of human parturition.
authors.affiliation: Department of Obstetrics and Gynaecology, Monash University, Clayton, Victoria, Australia.
authors.forename: M
authors.initials: M
authors.lastname: Schneider-Kolsky
authors.forename: D
authors.initials: D
authors.lastname: D'Antona
authors.forename: L W
authors.initials: LW
authors.lastname: Evans
authors.forename: N
authors.initials: N
authors.lastname: Taylor
authors.forename: A
authors.initials: A
authors.lastname: O'Connor
authors.forename: N P
authors.initials: NP
authors.lastname: Groome
authors.forename: D
authors.initials: D
authors.lastname: de Kretser
authors.forename: E M
authors.initials: EM
authors.lastname: Wallace
mesh_terms: D028341:Activins; D015415:Biomarkers / Q000097:blood; D003430:Cross-Sectional Studies; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D038681:Follistatin; D006023:Glycoproteins / Q000097:blood*; D006133:Growth Substances / Q000097:blood*; D006801:Humans; D007265:Inhibins / Q000097:blood*; D007745:Labor Onset / Q000097:blood; D008137:Longitudinal Studies; D011247:Pregnancy / Q000097:blood*; D011263:Pregnancy Trimester, Third / Q000097:blood
chemical_list: D015415:Biomarkers; D038681:Follistatin; D006023:Glycoproteins; D006133:Growth Substances; D028341:Activins; D007265:Inhibins