title: Histologic changes of the fetal membranes after fetoscopic laser surgery for twin-twin transfusion syndrome.
abstract: BACKGROUND
  Preterm premature rupture of membranes remains a major complication after fetoscopic laser surgery (FLS) for twin-twin transfusion syndrome (TTTS). We studied the histologic changes of fetal membranes post-FLS and investigated a possible impact of amniotic fluid (AF) dilution.
  
  
  METHODS
  Fetal membranes of 31 pregnancies that underwent FLS for TTTS were investigated histologically at delivery at different sites: trocar site of recipient sac and at distance, donor sac, and inter-twin membrane.
  
  
  RESULTS
  The trocar insertion site on the recipient sac showed no signs of histologic hallmarks of healing. Wide-spread alteration in collagen organization and higher apoptotic index in the amnion of the recipient sac which were absent in donor's and reference membranes. To explain the mechanisms, we analyzed the AF composition of recipient sacs from TTTS pregnancies vs. GA-matched healthy singleton controls and found glucose, protein and lactate dehydrogenase activity were all significantly lower in TTTS sacs consistent with over-dilution of recipient's AF (~2-fold). In-vitro exposure of healthy amniochorion to analogous dilutional stress conditions recapitulated the histologic changes and induced apoptosis and autophagy.
  
  
  CONCLUSIONS
  Alteration in structural integrity of the recipient's amniochorion, possibly in response to dilution stress, along with ineffective repair mechanisms may explain the increased incidence of preterm birth post-FLS.
authors.affiliation: 1] Department of Obstetrics, Gynecology & Reproductive Sciences, Yale University School of Medicine, New Haven, Connecticut [2] The Fetal Center at Children's Memorial Hermann Hospital, Department of Obstetrics, Gynecology & Reproductive Sciences, The University of Texas Health Medical School, Houston, Texas.
authors.forename: Ramesha
authors.initials: R
authors.lastname: Papanna
authors.affiliation: The Fetal Center at Children's Memorial Hermann Hospital, Department of Obstetrics, Gynecology & Reproductive Sciences, The University of Texas Health Medical School, Houston, Texas.
authors.forename: Lovepreet K
authors.initials: LK
authors.lastname: Mann
authors.affiliation: The Fetal Center at Children's Memorial Hermann Hospital, Department of Obstetrics, Gynecology & Reproductive Sciences, The University of Texas Health Medical School, Houston, Texas.
authors.forename: Kenneth J
authors.initials: KJ
authors.lastname: Moise
authors.affiliation: Department of Pathology, Yale University School of Medicine, New Haven, Connecticut.
authors.forename: Themis
authors.initials: T
authors.lastname: Kyriakides
authors.affiliation: The Fetal Center at Children's Memorial Hermann Hospital, Department of Obstetrics, Gynecology & Reproductive Sciences, The University of Texas Health Medical School, Houston, Texas.
authors.forename: Anthony
authors.initials: A
authors.lastname: Johnson
authors.affiliation: The Fetal Center at Children's Memorial Hermann Hospital, Department of Obstetrics, Gynecology & Reproductive Sciences, The University of Texas Health Medical School, Houston, Texas.
authors.forename: Elisa
authors.initials: E
authors.lastname: Garcia
authors.affiliation: Division of Maternal-Fetal Medicine, Department of Obstetrics & Gynecology, The Ohio State University Wexner Medical Center, Columbus, Ohio.
authors.forename: Catalin S
authors.initials: CS
authors.lastname: Buhimschi
authors.affiliation: 1] Division of Maternal-Fetal Medicine, Department of Obstetrics & Gynecology, The Ohio State University Wexner Medical Center, Columbus, Ohio [2] Center for Perinatal Research, The Research Institute at Nationwide Children's Hospital, Columbus, Ohio [3] Department of Pediatrics, The Ohio State University College of Medicine, Columbus, Ohio.
authors.forename: Irina A
authors.initials: IA
authors.lastname: Buhimschi
mesh_terms: D000328:Adult; D000653:Amniotic Fluid / Q000737:chemistry; D017209:Apoptosis; D001343:Autophagy; D005321:Extraembryonic Membranes / Q000473:pathology*; D005260:Female; D005322:Premature Rupture of Fetal Membranes / Q000209:etiology / Q000517:prevention & control; D005330:Fetofetal Transfusion / Q000503:physiopathology* / Q000601:surgery*; D005332:Fetoscopy / Q000009:adverse effects* / Q000379:methods*; D005865:Gestational Age; D005947:Glucose / Q000032:analysis; D006801:Humans; D007150:Immunohistochemistry; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D007834:Lasers; D011247:Pregnancy; D011256:Pregnancy Outcome; D047928:Premature Birth; D014427:Twins
chemical_list: D007770:L-Lactate Dehydrogenase; D005947:Glucose