title: Term twin birth - impact of mode of delivery on outcome.
abstract: BACKGROUND
  The main aims of this study were to compare maternal and neonatal outcomes in term twin birth according to the planned mode of delivery and to study the effects of chorionicity and inter-twin delivery time on neonatal outcome.
  
  
  METHODS
  A single-center cohort study of 495 women with twin deliveries at ≥37+0weeks of gestation. Term twin deliveries were divided into a trial of labor group (TOL, 69.3%) and a planned cesarean section (CS) group (30.7%). The primary outcomes were maternal and neonatal morbidity.
  
  
  RESULTS
  80.8% of women attempting TOL achieved vaginal birth. In the TOL group, mothers had less bleeding [median 500 mL (range 150-2700 mL) vs. 950 mL (range 150-3500 mL), p < 0.001) and fewer surgical complications (3.2% vs. 8.6%, p = 0.011), whereas second twins more often had five-minute Apgar scores of <7 (5.0% vs. 0%, p = 0.002) or umbilical artery pH < 7.05 (5.7% vs. 0%, p = 0.003), compared with the planned CS group. There was a slight, non-significant tendency for more NICU admissions in the TOL group, yet the need for NICU treatment was infrequent in the whole study material. Outcomes among dichorionic (DC) second twins were similar to those in the whole material, but among monochorionic (MC) second twins there were no differences between the TOL and planned CS groups. In secondary analysis, a five-minute Apgar score <7 occurred significantly more often in the DC group among second twins if the inter-twin delivery time exceeded 30 min.
  
  
  CONCLUSIONS
  TOL is a good option for women with twin pregnancy at term, regardless of chorionicity. Active management of labor for the second twin is important, also in DC births. Maternal outcomes were more favorable with TOL and although low Apgar scores and low umbilical blood pH may be more frequent after TOL - especially with the second twin - serious neonatal morbidity is rare and does not differ from that after planned CS.
authors.affiliation: School of Medicine, University of Tampere, Tampere, Finland.|Department of Obstetrics and Gynecology, Tampere University Hospital, Tampere, Finland.
authors.forename: Elina
authors.identifier: http://orcid.org/0000-0001-9547-8733
authors.initials: E
authors.lastname: Ylilehto
authors.affiliation: Department of Obstetrics and Gynecology, Tampere University Hospital, Tampere, Finland.
authors.forename: Outi
authors.identifier: http://orcid.org/0000-0003-0161-7486
authors.initials: O
authors.lastname: Palomäki
authors.affiliation: School of Health Sciences, University of Tampere, Tampere, Finland.
authors.forename: Heini
authors.initials: H
authors.lastname: Huhtala
authors.affiliation: School of Medicine, University of Tampere, Tampere, Finland.|Department of Obstetrics and Gynecology, Tampere University Hospital, Tampere, Finland.
authors.forename: Jukka
authors.initials: J
authors.lastname: Uotila
mesh_terms: D000328:Adult; D002585:Cesarean Section; D015331:Cohort Studies; D036861:Delivery, Obstetric / Q000379:methods*; D005260:Female; D005387:Finland; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D007744:Obstetric Labor Complications; D011247:Pregnancy; D011256:Pregnancy Outcome; D059285:Pregnancy, Twin; D014219:Trial of Labor; D014427:Twins
keywords: Twin birth; chorionicity; inter-twin delivery time; mode of delivery; trial of labor