title: Does childbirth alter the reflex pelvic floor response to coughing?
abstract: OBJECTIVE
  To determine the prevalence of and to quantify the effect of reflex pelvic floor activation on coughing in nulliparous pregnant women, and to assess peripartal changes and any association with stress urinary incontinence.
  
  
  METHODS
  Between April 2008 and March 2010, 131 nulliparous pregnant women were recruited from an antenatal clinic. All participants were interviewed and underwent four-dimensional translabial ultrasound examination at antepartum (35.8 (mean) weeks' gestation) and postpartum (4.6 (mean) months) visits. Four-dimensional ultrasound volume datasets of the pelvic floor during coughs were obtained at a minimum frame rate of 16 Hz, using a 10° volume acquisition angle. To quantify a reflex levator contraction we measured the midsagittal hiatal diameter at multiple time points. Levator integrity was determined using tomographic ultrasound imaging.
  
  
  RESULTS
  From 131 women recruited, 47 datasets were technically suboptimal, leaving 84. There was a visible pelvic floor reflex in 82 (98%) cases. At the postpartum visit this was reduced to 63/84, i.e. 75% (P < 0.001). The magnitude of a reflex contraction was markedly reduced postpartum, from 4.8 mm to 2.0 mm (P < 0.001), and this effect was associated with delivery mode (P = 0.042). There was a trend towards an association between lower reflex contraction magnitude and stress incontinence (0.87 ± 3.18 mm vs. 2.36 ± 3.5 mm; P = 0.08) at the postpartum follow-up visit.
  
  
  CONCLUSIONS
  Pelvic floor reflexes are altered by childbirth. This alteration may be associated with vaginal delivery. Reflex magnitude may be associated with postpartum stress urinary incontinence. The clinical significance of this finding is uncertain.
authors: Sydney Medical School Nepean, Penrith, Australia. hpdietz@bigpond.com
authors: H P
authors: HP
authors: Dietz
authors: V
authors: V
authors: Bond
authors: K L
authors: KL
authors: Shek
mesh_terms: D000328:Adult; D015992:Body Mass Index; D003371:Cough / Q000503:physiopathology; D036861:Delivery, Obstetric / Q000009:adverse effects*; D005260:Female; D006801:Humans; D010298:Parity; D017773:Pelvic Floor / Q000000981:diagnostic imaging / Q000293:injuries* / Q000503:physiopathology*; D049590:Postpartum Period; D011237:Predictive Value of Tests; D011247:Pregnancy; D011248:Pregnancy Complications; D015995:Prevalence; D011446:Prospective Studies; D015203:Reproducibility of Results; D018570:Risk Assessment; D012307:Risk Factors; D014463:Ultrasonography; D014550:Urinary Incontinence, Stress / Q000000981:diagnostic imaging / Q000209:etiology* / Q000503:physiopathology