title: Obesity decreases the chance to deliver spontaneously.
abstract: OBJECTIVE
  To evaluate the impact of maternal obesity on labour, intrapartual assessment and delivery.
  
  
  METHODS
  Retrospective cohort analysis of n = 11,681 deliveries supervised between 01 January 2000 and 31 December 2009. Results were analysed dividing the patients into two main groups according to their body mass index (BMI): group 1, control: BMI 18-24.9 and group 2 BMI, test >25. Subgroups were built: (0) BMI 25-29.9, (I) BMI 30-34.9, (II) BMI 35-39.9, (III) BMI >40. Exclusion criteria were defined as: delivery <37 + 0 weeks p.m., multiple pregnancy, comorbidity other than GDM, abnormal presentation, BMI <18.5, and incomplete data. The main outcome parameter was defined as secondary caesarean delivery rate and mode of delivery.
  
  
  RESULTS
  N = 8,379 patients met the inclusion criteria and were divided in two groups: 1, n = 4,464 patients and 2, n = 3,915. Basic maternal characteristics including foetal vital parameters were equal in all groups. GDM occurred more frequently in obese patients (P < 0.001). For the main outcome parameter a significant decrease in the rate of spontaneous delivery between control/test groups (72-66%, P < 0.001) and control/I-III groups (72 vs. 50%, P < 0.001) could be observed. The rate of secondary c-section increased significantly according to a higher BMI (>40: OR 2.5, 95% CI 1.84-3.61, χ (2) P < 0.001). The groups showed no difference in the rate of injuries during delivery though foetal birth weight increased significantly with a higher BMI (3,412-3,681 g; P < 0.001).
  
  
  CONCLUSIONS
  Obesity decreases the chance to deliver spontaneously. Moreover, the obese patient suffers from a significantly longer trial of labour (7.9 vs. 9.5 h) and an elevated risk of surgical delivery.
authors.affiliation: Division of Perinatal Medicine, Department of Obstetrics and Gynaecology, Schleswig-Holstein University, Campus Lübeck, Ratzeburger Allee 160, 23538 Lübeck, Germany. daniel.beyer@uk-sh.de
authors.forename: Daniel Alexander
authors.initials: DA
authors.lastname: Beyer
authors.forename: Feriel
authors.initials: F
authors.lastname: Amari
authors.forename: Dörte W
authors.initials: DW
authors.lastname: Lüdders
authors.forename: Klaus
authors.initials: K
authors.lastname: Diedrich
authors.forename: Jan
authors.initials: J
authors.lastname: Weichert
mesh_terms: D000328:Adult; D015992:Body Mass Index; D002585:Cesarean Section / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D009765:Obesity / Q000150:complications*; D007744:Obstetric Labor Complications / Q000209:etiology*; D011247:Pregnancy; D012189:Retrospective Studies