Amniotic fluid embolism: a catastrophic incident in pregnancy

Amniotic fluid embolism

Abstract

Objective: Amniotic fluid embolism (AFE) is a rare entity that occurs during pregnancy, about which there is limited information currently. This study aimed to contribute to the literature by evaluating histopathologic findings, clinical data, and autopsy findings of the cases from a postmortem point of view.

Methods: A 10-year retrospective study was designed to assess deaths during pregnancy. To address vascular structures and identify the squamous cells, immunohistochemical staining was performed on the lung specimens of individuals who underwent autopsy due to sudden death during this period and were diagnosed with amnion embolism. Demographic data and clinical findings of the cases were obtained from the institutional archive and evaluated together with autopsy and histopathologic findings.

Results: During a 10-year period, 89 pregnant women were autopsied and five were diagnosed with amniotic fluid embolism. In all cases, macroscopic examination revealed subpleural petechial hemorrhages in the lungs, and hematoxylin-eosin (HE)-stained sections of the lungs showed scales and squamous cells in pulmonary vessel lumens. Immunohistochemical staining with CD34 in vascular structures and with pankeratin (PANCK) in scales and squamous cells was detected in all cases. There was no pathology in other organs on macroscopic and microscopic examination. No drugs or toxins were detected in the blood and body fluids in the toxologic analysis. Two decedents had symptoms before labor and two decedents had symptoms during labor. One decedent had symptoms just after she gave birth vaginally. Four of them had emergency c-sections. In three cases, uterine rupture followed by hysterectomy was observed, and in two cases, the fetus also died with the mother. Three fetuses whose mothers died due to amniotic fluid embolism were rescued alive.

Conclusion: This study underlines uterine rupture and Cesarean sections as crucial risk factors for AFE, but no connection was found with older maternal age. Although AFE is such a devastating picture, there is still no agreed diagnostic definition currently. This study supports the reliability of the clinical parameters recommended in the Paris AFE framework, which was based on clinical findings. These criteria can also be used in our country in places with more limited conditions. This study emphasizes that it is critical to evaluate patients with echocardiography, which is available in many centers in Turkey, in cases of pregnancy with unstoppable vaginal bleeding that starts with hypotension and neurological findings. The postmortem data can contribute to the recognition of its unique clinical and histopathological manifestations, which can be used for maternal and infant survival.