Reduction of circulating annexin A5 levels and resistance to annexin A5 anticoagulant activity in women with recurrent spontaneous pregnancy losses

Am J Obstet Gynecol. 2006 Jan;194(1):182-8. doi: 10.1016/j.ajog.2005.05.034.


Objective: We investigated whether levels of annexin A5, evidence for resistance to annexin A5 activity, and levels anti-annexin A5 antibodies might be altered in women with a history of recurrent spontaneous pregnancy losses.

Study design: These annexin A5 parameters were assayed in 70 nonpregnant women with a history of > or = 3 recurrent spontaneous pregnancy losses (cases) and 50 women without adverse pregnancy history (control subjects).

Results: Cases had significantly lower plasma annexin A5 levels than control subjects (median, 4.7 ng/mL [range, 0.3-40.4 ng/mL] vs 6.7 ng/mL [range, 0.7-56.0]; P = .01), significantly reduced anticoagulant ratios (188% [range, 119%-279%] vs 238% [range, 159%-286%]; P < .0001), and reduced binding of annexin A5 to phospholipid (6.3 ng/aliquot phospholipid [range, 1.5-16.4 ng/aliquot phospholipid] vs 9.7 ng/aliquot phospholipid (range, 3.5-17.0 ng/aliquot phospholipid]; P = .0002). There were no significant differences in anti-annexin A5 antibody levels.

Conclusion: Reduction of annexin A5 and interference with its anticoagulant and binding activities are associated significantly with a history of recurrent spontaneous pregnancy losses. These data support the concept of a significant role for annexin A5 in the maintenance of pregnancy.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Abortion, Habitual / blood*
  • Adult
  • Annexin A5 / blood*
  • Annexin A5 / immunology*
  • Annexin A5 / metabolism
  • Antibodies / blood*
  • Antibodies, Anticardiolipin / blood
  • Anticoagulants / blood*
  • Anticoagulants / immunology*
  • Case-Control Studies
  • Drug Resistance
  • Female
  • Humans
  • Medical Records
  • Phospholipids / metabolism
  • Pregnancy


  • Annexin A5
  • Antibodies
  • Antibodies, Anticardiolipin
  • Anticoagulants
  • Phospholipids