The impact of pregnancy and childbirth on pelvic sensation: a prospective cohort study.

Pelvic organ prolapse, urinary, bowel and sexual dysfunction, collectively called pelvic floor dysfunction (PFD) affects 1 in 3 women and has a significant public health impact. The causes of PFD are not fully understood but involve injury to connective tissue and motor nerve during childbirth. Women with PFD also have sensory nerve impairment, and it is likely this occurs during childbirth, but this has never been investigated. In the current study 150 women underwent quantitative sensory testing for vibration sensation at the vagina and clitoris, and stretch sensation at the vagina and introitus, in the third trimester, 3 and 6 months postnatal. Antenatally vibration sensation was reduced but stretch sensation was normal. Postnatally vibration sensation deteriorated whilst stretch sensation initially deteriorated but recovered by 6 months postnatal to antenatal levels (all p < 0.001). Mode of birth had a significant impact on sensation, with caesarean section appearing neuroprotective, normal vaginal birth resulted in a transient deterioration in sensation that recovered by 6 months, whilst assisted vaginal delivery was prolonged suggesting persistent neurological impairment (all p < 0.015). Further research is required to study the clinical effect of these changes on pelvic floor dysfunction in the medium and long-term.