title: Effect of antenatal pelvic floor muscle training on labor and birth.
abstract: OBJECTIVE
  To estimate whether women doing pelvic floor muscle training before and during pregnancy have increased risk of perineal lacerations, episiotomy, vacuum/forceps delivery, or acute cesarean delivery.
  
  
  METHODS
  Participants were 18,865 primiparous women in the Norwegian Mother and Child Cohort Study, conducted by the Norwegian Institute of Public Health. Data were collected by self-completed questionnaires at gestational weeks 17 and 30 and analyzed by logistic regression analysis. Data about obstetric outcomes were obtained from the Medical Birth Registry of Norway. Pelvic floor muscle training was categorized as less than once per week, one to two times per week, and at least three times per week both before and during pregnancy. The results are presented as adjusted odds ratios (OR) with 95% confidence intervals (CIs).
  
  
  RESULTS
  Of women who performed pelvic floor muscle training less than once per week, 7.2% sustained a third-degree or fourth-degree laceration compared with 6.3% of women who performed pelvic floor muscle training at least three times per week. A similar pattern was present for rates of episiotomy (29.1% compared with 24.9%), vacuum/forceps delivery (15.9% compared with 15.0%), and acute cesarean delivery (9.5% compared with 7.5%). Adjusting for factors that might be associated with pelvic floor muscle training and the outcomes under study did not distort the effect of pelvic floor muscle training. Exercising at least three times per week was not associated with third-degree and fourth-degree perineal lacerations, episiotomy, vacuum/forceps delivery, or acute cesarean delivery (adjusted OR 0.86 [95% CI 0.60-1.24], 0.82 [0.67-1.01], 0.95 [0.74-1.22], and 0.75 [0.53-1.05], respectively).
  
  
  CONCLUSIONS
  Pelvic floor muscle training before and during pregnancy does not affect labor and birth outcomes or complication rates.
  
  
  METHODS
  II.
authors.affiliation: From the Norwegian School of Sport Sciences, Department of Sports Medicine, Oslo, Norway; and the Norwegian Institute of Public Health, Division of Epidemiology, Oslo, Norway.
authors.forename: Kari
authors.initials: K
authors.lastname: Bø
authors.forename: Caroline
authors.initials: C
authors.lastname: Fleten
authors.forename: Wenche
authors.initials: W
authors.lastname: Nystad
mesh_terms: D000293:Adolescent; D000328:Adult; D005081:Exercise Therapy / Q000009:adverse effects* / Q000379:methods; D005260:Female; D006801:Humans; D007743:Labor, Obstetric / Q000502:physiology*; D008875:Middle Aged; D009119:Muscle Contraction; D007744:Obstetric Labor Complications / Q000209:etiology; D036801:Parturition / Q000502:physiology*; D017773:Pelvic Floor / Q000502:physiology*; D010502:Perineum / Q000293:injuries; D011247:Pregnancy; D016896:Treatment Outcome