title: Internal Herniation in Pregnancy After Gastric Bypass: A Systematic Review.
abstract: OBJECTIVE
  To assess maternal and fetal outcomes of pregnancies complicated by internal herniation after Roux-en-Y gastric bypass.
  
  
  METHODS
  Articles were identified through searches in online databases (ClinicalTrials.gov, MEDLINE, EMBASE, PubMed, and Google Scholar) from January 1980 to March 2015 for the following terms: [gastric bypass OR bariatric surgery] AND [pregnancy] AND [complication OR herniation OR obstruction]. Reference lists of relevant articles were hand-searched. Additionally, we searched our own hospital's obstetric database for cases of internal herniation after Roux-en-Y gastric bypass.
  
  
  METHODS
  Only articles in English and studies in humans were selected. Cases of internal herniation outside of pregnancy or internal herniation without a history of Roux-en-Y gastric bypass were excluded. Of 384 articles identified by the initial search, 22 were retained for further analysis.
  
  
  RESULTS
  All retrieved articles were case reports or case series. There were no interventional studies. We retrieved 47 cases from the literature and five cases from our own database. The mean gestational age at diagnosis was 28.4±7.3 weeks. All women presented with abdominal pain. Nausea and vomiting were present in only 65%. Ultrasonography and laboratory results are usually noninformative, and computed tomography or magnetic resonance imaging confirmed the diagnosis in only 75% of cases. Nine of 52 women (17.3%) required bowel resections. There were two maternal deaths and three perinatal deaths, all in women treated later than 48 hours after onset of the symptoms.
  
  
  CONCLUSIONS
  Internal herniation complicating pregnancy after Roux-en-Y gastric bypass typically presents with subtle signs in the third trimester of pregnancy. Timely recognition and early surgical intervention are associated with a reduced risk of bowel ischemia and maternal and fetal adverse outcomes.
authors.affiliation: Departments of Obstetrics and Gynecology and Abdominal Surgery, University Hospitals Leuven, and the Department of Development and Regeneration, Katholieke Universiteit Leuven, Leuven, Belgium.
authors.forename: Valerie
authors.initials: V
authors.lastname: Vannevel
authors.forename: Goele
authors.initials: G
authors.lastname: Jans
authors.forename: Magdalena
authors.initials: M
authors.lastname: Bialecka
authors.forename: Matthias
authors.initials: M
authors.lastname: Lannoo
authors.forename: Roland
authors.initials: R
authors.lastname: Devlieger
authors.forename: Tim
authors.initials: T
authors.lastname: Van Mieghem
mesh_terms: D000713:Anastomosis, Roux-en-Y / Q000009:adverse effects*; D005260:Female; D015390:Gastric Bypass / Q000009:adverse effects*; D006547:Hernia / Q000000981:diagnostic imaging / Q000209:etiology*; D006801:Humans; D011247:Pregnancy; D011248:Pregnancy Complications / Q000000981:diagnostic imaging / Q000209:etiology*; D012307:Risk Factors