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Amniotic fluid embolism syndrome

INTRODUCTION

Amniotic fluid embolism syndrome (also called anaphylactoid syndrome of pregnancy) is a catastrophic condition that occurs during pregnancy or shortly after delivery [1,2]. Although first reported in 1926, it was not widely recognized until 1941 when an autopsy series of eight women who had died from sudden shock during labor reported squamous cells and mucin of fetal origin in the maternal pulmonary vasculature [3,4]. Fetal squamous cells have also been described in the vascular beds of the maternal kidneys, liver, spleen, pancreas, and brain [5].

Amniotic fluid embolism syndrome is reviewed here. The management of critically ill obstetric patients is discussed separately, including those with venous thromboembolism. (See "Critical illness during pregnancy and peripartum" and "Deep vein thrombosis and pulmonary embolism in pregnancy: Treatment".)

INCIDENCE

Amniotic fluid embolism syndrome is rare. Most studies estimate that one case occurs in every 8000 to 80,000 deliveries [6-9]. As an example, one retrospective cohort study of three million birth records identified 7.7 cases per 100,000 births [6].

RISK FACTORS

Several factors have been associated with amniotic fluid embolism syndrome. They include precipitous or tumultuous labor, advanced maternal age, cesarean and instrumental delivery, placenta previa and abruption, grand multiparity (≥5 live births or stillbirths), cervical lacerations, fetal distress, eclampsia, and medical induction of labor [6,10]. Despite the associations, our current understanding of the pathogenesis suggests that these factors probably are not the cause of amniotic fluid embolism syndrome. The syndrome is best considered unpredictable and unpreventable.

PATHOPHYSIOLOGY

Amniotic fluid probably enters the maternal circulation through the endocervical veins, the placental insertion site, or a site of uterine trauma [11]. Once it reaches the maternal circulation, it can precipitate cardiogenic shock, respiratory failure, and, possibly, an inflammatory response.
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References Top
  1. Gilmore, DA, Wakim, J, Secrest, J, Rawson, R. Anaphylactoid syndrome of pregnancy: a review of the literature with latest management and outcome data. AANA J 2003; 71:120.
  2. Gist, RS, Stafford, IP, Leibowitz, AB, Beilin, Y. Amniotic fluid embolism. Anesth Analg 2009; 108:1599.
  3. Meyer, JR. Embolia pulmonar amnio caseosa. Brasil Medico 1926; 2:301.
  4. Steiner, PE, Lushbaugh, CC. Landmark article, Oct. 1941: Maternal pulmonary embolism by amniotic fluid as a cause of obstetric shock and unexpected deaths in obstetrics. By Paul E. Steiner and C. C. Lushbaugh. JAMA 1986; 255:2187.
  5. Liban, E, Raz, S. A clinicopathologic study of fourteen cases of amniotic fluid embolism. Am J Clin Pathol 1969; 51:477.
  6. Abenhaim, HA, Azoulay, L, Kramer, MS, Leduc, L. Incidence and risk factors of amniotic fluid embolisms: a population-based study on 3 million births in the United States. Am J Obstet Gynecol 2008; 199:49.
  7. Clark, SL, Hankins, GD, Dudley, DA, et al. Amniotic fluid embolism: Analysis of the national registry. Am J Obstet Gynecol 1995; 172:1158.
  8. Tuffnell, DJ. United kingdom amniotic fluid embolism register. BJOG 2005; 112:1625.
  9. Morgan, M. Amniotic fluid embolism. Anaesthesia 1979; 34:20.
  10. Turner, LA, Kramer, MS, Liu, S. Cause-specific mortality during and after pregnancy and the definition of maternal death. Chronic Dis Can 2002; 23:31.
  11. Courtney, LD. Amniotic fluid embolism. Obstet Gynecol Surv 1974; 29:169.
  12. Clark, SL. New concepts of amniotic fluid embolism: a review. Obstet Gynecol Surv 1990; 45:360.
  13. Attwood, HD, Downing, ES. Experimental amniotic fluid and meconium embolism. Surg Gynecol Obstet 1965; 120:255.
  14. Reis, RL, Pierce, WS, Behrendt, DM. Hemodynamic effects of amniotic fluid embolism. Surg Gynecol Obstet 1969; 129:45.
  15. Clark, SL, Cotton, DB, Gonik, B, et al. Central hemodynamic alterations in amniotic fluid embolism. Am J Obstet Gynecol 1988; 158:1124.
  16. Clark, SL, Montz, FJ, Phelan, JP. Hemodynamic alterations associated with amniotic fluid embolism: A reappraisal. Am J Obstet Gynecol 1985; 151:617.
  17. Shechtman, M, Ziser, A, Markovits, R, Rozenberg, B. Amniotic fluid embolism: early findings of transesophageal echocardiography. Anesth Analg 1999; 89:1456.
  18. Stanten, RD, Iverson, LI, Daugharty, TM, et al. Amniotic fluid embolism causing catastrophic pulmonary vasoconstriction: diagnosis by transesophageal echocardiogram and treatment by cardiopulmonary bypass. Obstet Gynecol 2003; 102:496.
  19. Price, TM, Baker, VV, Cefalo, RC. Amniotic fluid embolism. Three case reports with a review of the literature. Obstet Gynecol Surv 1985; 40:462.
  20. Nishio, H, Matsui, K, Miyazaki, T, et al. A fatal case of amniotic fluid embolism with elevation of serum mast cell tryptase. Forensic Sci Int 2002; 126:53.
  21. Farrar, SC, Gherman, RB. Serum tryptase analysis in a woman with amniotic fluid embolism. A case report. J Reprod Med 2001; 46:926.
  22. Benson, MD, Kobayashi, H, Silver, RK, et al. Immunologic studies in presumed amniotic fluid embolism. Obstet Gynecol 2001; 97:510.
  23. Fineschi, V, Gambassi, R, Gherardi, M, Turillazzi, E. The diagnosis of amniotic fluid embolism: an immunohistochemical study for the quantification of pulmonary mast cell tryptase. Int J Legal Med 1998; 111:238.
  24. Benson, MD. A hypothesis regarding complement activation and amniotic fluid embolism. Med Hypotheses 2007; 68:1019.
  25. Azegami, M, Mori, N. Amniotic fluid embolism and leukotrienes. Am J Obstet Gynecol 1986; 155:1119.
  26. Benson, MD. Nonfatal amniotic fluid embolism. Arch Fam Med 1993; 2:989.
  27. Lawson, HW, Atrash, HK, Franks, AL. Fatal pulmonary embolism during legal induced abortion in the United States from 1972 to 1985. Am J Obstet Gynecol 1990; 162:986.
  28. Hasaart, TH, Essed, GG. Amniotic fluid embolism after transabdominal amniocentesis. Eur J Obstet Gynecol Reprod Biol 1983; 16:25.
  29. Mainprize, TC, Maltby, JR. Amniotic fluid embolism: a report of four probable cases. Can Anaesth Soc J 1986; 33:382.
  30. Ellingsen, CL, Eggebo, TM, Lexow, K. Amniotic fluid embolism after blunt abdominal trauma. Resuscitation 2007; 75:180.
  31. Rainio, J, Penttila, A. Amniotic fluid embolism as cause of death in a car accident--a case report. Forensic Sci Int 2003; 137:231.
  32. Masson, RG, Ruggieri, J, Siddiqui, MM. Amniotic fluid embolism: Definitive diagnosis in a survivor. Am Rev Respir Dis 1979; 120:187.
  33. Wasser, WG, Tessler, S, Kamath, CP, Sackin, AJ. Nonfatal amniotic fluid embolism: A case report of postpartum respiratory distress with histopathologic studies. Mt Sinai J Med 1979; 46:388.
  34. Peterson, EP, Taylor, HB. Amniotic fluid embolism. An analysis of 40 cases. Obstet Gynecol 1970; 35:787.
  35. Beller, FK. Disseminated intravascular coagulation consumption coagulopathy in obstetrics. Obstet Gynecol Annu 1974; 3:267.
  36. Bastien, JL, Graves, JR, Bailey, S. Atypical presentation of amniotic fluid embolism. Anesth Analg 1998; 87:124.
  37. Malhotra, P, Agarwal, R, Awasthi, A, et al. Delayed presentation of amniotic fluid embolism: lessons from a case diagnosed at autopsy. Respirology 2007; 12:148.
  38. Davies, S. Amniotic fluid embolism and isolated disseminated intravascular coagulation. Can J Anaesth 1999; 46:456.
  39. Lee, W, Ginsburg, KA, Cotton, DB, Kaufman, RH. Squamous and trophoblastic cells in the maternal pulmonary circulation identified by invasive hemodynamic monitoring during the peripartum period. Am J Obstet Gynecol 1986; 155:999.
  40. Oi, H, Kobayashi, H, Hirashima, Y, et al. Serological and immunohistochemical diagnosis of amniotic fluid embolism. Semin Thromb Hemost 1998; 24:479.
  41. Kobayashi, H, Ooi, H, Hayakawa, H, et al. Histological diagnosis of amniotic fluid embolism by monoclonal antibody TKH-2 that recognizes NeuAc alpha 2-6GalNAc epitope. Hum Pathol 1997; 28:428.
  42. Clark, SL. Amniotic fluid embolism. Crit Care Clin 1991; 7:877.
  43. Vanmaele, L, Noppen, M, Vincken, M, et al. Transient left heart failure in amniotic fluid embolism. Intensive Care Med 1990; 16:269.
  44. Wulf, KH, Kunzel, W, Lehman, V. Clinical aspects of placental gas exchange. In: Longo, LD, Bartels, H (Eds), Respiratory gas exchange and blood flow in the placenta. United States Public Health Service, Bethesda, MD, 1972. p. 505.
  45. McDonnell, NJ, Chan, BO, Frengley, RW. Rapid reversal of critical haemodynamic compromise with nitric oxide in a parturient with amniotic fluid embolism. Int J Obstet Anesth 2007; 16:269.
  46. Nagarsheth, NP, Pinney, S, Bassily-Marcus, A, et al. Successful placement of a right ventricular assist device for treatment of a presumed amniotic fluid embolism. Anesth Analg 2008; 107:962.
  47. Hsieh, YY, Chang, CC, Li, PC, et al. Successful application of extracorporeal membrane oxygenation and intra-aortic balloon counterpulsation as lifesaving therapy for a patient with amniotic fluid embolism. Am J Obstet Gynecol 2000; 183:496.
  48. Gilbert, WM, Danielsen, B. Amniotic fluid embolism: decreased mortality in a population-based study. Obstet Gynecol 1999; 93:973.
  49. Clark, SL. Amniotic fluid embolism. Clin Perinatol 1986; 13:801.
  50. Suidan, JS. Amniotic fluid embolism. Middle East J Anesthesiol 1989; 10:279.
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