title: Iatrogenic perforation of intertwin membrane after laser surgery for twin-to-twin transfusion syndrome.
abstract: OBJECTIVE
  To evaluate management and outcome of iatrogenic monoamniotic twins (iMAT) compared with twins with intact intertwin dividing membranes after laser surgery for twin-to-twin transfusion syndrome (TTTS).
  
  
  METHODS
  This was a retrospective analysis of twins with and without iatrogenic rupture of the intertwin membranes that had been treated for TTTS with laser surgery at our center between 2004 and 2012. Primary outcomes were perinatal survival and severe neonatal morbidity. Secondary outcomes were mode of delivery, gestational age at birth and cord entanglement.
  
  
  RESULTS
  In total, 338 pregnancies were included. In 67/338 (20%) pregnancies, iMAT was suspected antenatally. In 47 of these 67 (70%), a preterm Cesarean section was performed for monoamnionicity. Perinatal survival was 108/134 (81%) vs 396/542 (73%) in twins with intact intertwin membranes (P = 0.13). Mean gestational age at birth in iMAT was 31 completed weeks, compared to 33 weeks in twins with intact membranes (P < 0.01). At birth, cord entanglement was present in 8/67 (12%) iMAT pregnancies. Severe neonatal morbidity was assessed in 106/110 (96%) in iMAT cases and 392/416 (94%) in controls. The incidence of severe neonatal morbidity was 28/106 (26%) in iMAT vs 72/392 (18%) in controls (P = 0.25). Severe cerebral injury was significantly increased in the iMAT group as compared with controls, at 16/106 (15%) vs 18/392 (5%) (P < 0.01).
  
  
  CONCLUSIONS
  Iatrogenic rupture of intertwin membranes was suspected in 20% of pregnancies treated with laser therapy for TTTS and was associated with a lower gestational age at birth and increased neonatal morbidity.
authors: Department of Obstetrics, Leiden University Medical Center, Leiden, The Netherlands.
authors: S H P
authors: SH
authors: Peeters
authors: T T
authors: TT
authors: Stolk
authors: F
authors: F
authors: Slaghekke
authors: J M
authors: JM
authors: Middeldorp
authors: F J
authors: FJ
authors: Klumper
authors: E
authors: E
authors: Lopriore
authors: D
authors: D
authors: Oepkes
mesh_terms: D001724:Birth Weight; D005321:Extraembryonic Membranes / Q000293:injuries*; D005260:Female; D005322:Premature Rupture of Fetal Membranes / Q000209:etiology; D005330:Fetofetal Transfusion / Q000601:surgery*; D005332:Fetoscopy / Q000009:adverse effects; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D007232:Infant, Newborn, Diseases / Q000209:etiology; D053685:Laser Therapy / Q000009:adverse effects*; D054238:Perinatal Mortality; D011247:Pregnancy; D011256:Pregnancy Outcome; D059285:Pregnancy, Twin; D012086:Reoperation; D012189:Retrospective Studies; D016896:Treatment Outcome
keywords: complication; intertwin membrane; laser therapy; septostomy; twin-to-twin transfusion syndrome