Sydney Medical School Nepean, Penrith, Australia.
To determine the prevalence and to quantify reflex pelvic floor activation on coughing in nulliparous women, assess peripartal changes and any association with stress urinary incontinence.
Between April 2008 and March 2010, 131 nulliparous women were recruited from antenatal clinic. All participants underwent an interview and 4D translabial ultrasound at antepartal (mean 35.8 weeks' gestation) and postpartal (mean 4.6 months) appointments. Coughs were registered at a minimum of 16 Hz, using a 10 degree 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.
Of 131 women recruited, 47 datasets were technically suboptimal, leaving 84. There was a visible pelvic floor reflex in 82 (98%). At the postpartum appointment this was reduced to 63/84, ie., 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 reflex magnitude and stress incontinence (0.87 [SD 3.18] vs. 2.36 [3.5], P= 0.08) at the postpartum follow-up appointment.
Pelvic floor reflexes are altered by childbirth. This alteration may be associated with vaginal delivery. Reflex magnitude may be associated with postpartum urinary stress incontinence. The clinical significance of this finding is uncertain.
Dietz HP, Bond V, Shek KL. Are you the author?
Reference: Ultrasound Obstet Gynecol. 2011 Aug 25. Epub ahead of print.