title: Amniotic fluid embolism induces uterine anaphylaxis and atony following cervical laceration.
abstract: Amniotic fluid embolism (AFE) is a rare, high-risk obstetric complication primarily found in the lungs and potentially related to anaphylaxis. Tryptase release from the mast cell reflects anaphylaxis. Case report and findings: A female, aged over 40 years, presented with uterine atony and lethal hemorrhage after induced vaginal labor. Cervical laceration was accompanied by severe hemorrhage. Stromal edema and myometrial swelling were consistent with uterine atony. Alcian blue staining and zinc coproporphyrin immunostaining disclosed AFE, which was more prominent in the uterus than in the lungs. Tryptase immunostaining was diffuse and prominent around the activated mast cells (halos) in the uterus, including the cervix. Similar distribution of findings on the AFE markers, tryptase halos, complement receptor C5aR, and atony in the uterus suggested the causality of AFE to anaphylaxis, complement activation and atony. It is probable that disseminated intravascular coagulation (DIC), induced by AFE, uterine atony and cervical laceration, caused the lethal hemorrhage. It is likely that AFE, in association with cervical laceration, induces uterine anaphylaxis, complement activation, atony, DIC and lethal hemorrhage.
authors.affiliation: Department of Forensic Medicine, Graduate School of Medicine, University of Tokyo, Tokyo, Japan.
authors.forename: Naoaki
authors.initials: N
authors.lastname: Tamura
authors.forename: Hisashi
authors.initials: H
authors.lastname: Nagai
authors.forename: Hidyuki
authors.initials: H
authors.lastname: Maeda
authors.forename: Ryo-hei
authors.initials: RH
authors.lastname: Kuroda
authors.forename: Makoto
authors.initials: M
authors.lastname: Nakajima
authors.forename: Atsuko
authors.initials: A
authors.lastname: Igarashi
authors.forename: Naohiro
authors.initials: N
authors.lastname: Kanayama
authors.forename: Ken-ichi
authors.initials: K
authors.lastname: Yoshida
mesh_terms: D000328:Adult; D000707:Anaphylaxis / Q000209:etiology*; D002584:Cervix Uteri / Q000293:injuries*; D003167:Complement Activation; D004211:Disseminated Intravascular Coagulation / Q000209:etiology; D004619:Embolism, Amniotic Fluid / Q000473:pathology / Q000503:physiopathology*; D017809:Fatal Outcome; D005260:Female; D006470:Hemorrhage / Q000209:etiology; D006801:Humans; D007751:Labor, Induced / Q000009:adverse effects*; D022125:Lacerations; D008168:Lung / Q000098:blood supply / Q000473:pathology; D008407:Mast Cells / Q000201:enzymology; D011247:Pregnancy; D053802:Tryptases / Q000032:analysis / Q000276:immunology; D014593:Uterine Inertia / Q000209:etiology*; D014599:Uterus / Q000098:blood supply / Q000473:pathology
chemical_list: D053802:Tryptases