title: Influence of chorionicity in intra-partum management of twin deliveries.
abstract: OBJECTIVE
  To analyze morbidity and mortality in twin pregnancies as a function of the type of delivery and chorionicity.
  
  
  METHODS
  Retrospective cohort study.
  
  
  METHODS
  Analysis of the type of delivery, intertwin time interval, and perinatal variables of >1000 twin deliveries during a 10-year period.
  
  
  METHODS
  Influence of delivery type and chorionicity on perinatal outcome.
  
  
  RESULTS
  The rate of cesarean sections was 42.4%. No differences were found as a function of chorionicity or as a function of presentation of the second twin. Cesarean sections were performed after vaginal delivery of the first twin in 1.8% of cases, being more common if the second baby was in a non-cephalic presentation (6.9% vs. 0.4%, p < 0.05). The average twin-to-twin delivery time interval was longer in the cases where the second had a cephalic presentation (8.26 ± 7.75 min vs. 6.81 ± 5.97 min, p < 0.05). The umbilical artery pH was lower the longer the interval between the birth of the twins, both in monochorionic and dichorionic.
  
  
  CONCLUSIONS
  According to the results, vaginal delivery is as safe as elective caesarean section in twin pregnancies where the first twin is in cephalic presentation and the intrapartum management should not vary due to chorionicity.
authors.affiliation: Department of Obstetrics and Gynaecology, Cruces University Hospital, School of Medicine, University of the Basque Country, Biscay, Spain.
authors.forename: Eider
authors.initials: E
authors.lastname: Quintana
authors.forename: Jorge
authors.initials: J
authors.lastname: Burgos
authors.forename: Nekane
authors.initials: N
authors.lastname: Eguiguren
authors.forename: Juan Carlos
authors.initials: JC
authors.lastname: Melchor
authors.forename: Luis
authors.initials: L
authors.lastname: Fernández-Llebrez
authors.forename: Txantón
authors.initials: T
authors.lastname: Martínez-Astorquiza
mesh_terms: D002585:Cesarean Section / Q000706:statistics & numerical data; D002823:Chorion; D015331:Cohort Studies; D036861:Delivery, Obstetric / Q000379:methods*; D005260:Female; D005865:Gestational Age; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007231:Infant, Newborn; D007746:Labor Presentation; D010298:Parity; D011247:Pregnancy; D011256:Pregnancy Outcome; D059285:Pregnancy, Twin; D012189:Retrospective Studies; D013997:Time Factors; D014469:Umbilical Arteries