Changes in anal anatomy following vaginal delivery revealed by anal endosonography.
OBJECTIVE
To investigate changes in anal canal anatomy following vaginal delivery in women without apparent sphincter injury.


METHODS
Prospective controlled observational study.


METHODS
District general hospital.


METHODS
Consecutive parous and nulliparous women attending a gynaecology outpatient clinic.


METHODS
All women were examined using anal endosonography, and parous subjects without apparent sphincter injury compared with age-matched nulliparous controls to determine any differences in general anal canal morphology.


METHODS
Individual anal canal components were measured at defined levels and subjects compared with controls.


RESULTS
Twenty-one of 54 parous women had no anal sphincter scar. Compared with nulliparous women, they had significant anterior sphincter thinning (mean 3.7 mm vs 4.6 mm, P< 0.01) in association with lateral external sphincter thickening (mean 7.0 mm vs 4.4 mm, P<0.01), and longitudinal muscle thickening (mean 2.8 mm vs 2.1 mm, P< 001).


CONCLUSIONS
Specific changes in anal morphology have been demonstrated following vaginal delivery in women without apparent sphincter injury.
Frudinger
A
A
Intestinal Imaging Centre, Department of Obstetrics and Gynaecology, Northwick Park and St. Mark's NHS Hospitals Trust, Harrow, Middlesex, UK.
Halligan
S
S
Bartram
C I
CI
Spencer
J A
JA
Kamm
M A
MA
D000328:Adult; D001003:Anal Canal / Q000033:anatomy & histology* / Q000000981:diagnostic imaging*; D016022:Case-Control Studies; D036861:Delivery, Obstetric; D019160:Endosonography; D005260:Female; D006801:Humans; D008875:Middle Aged; D010298:Parity; D011247:Pregnancy; D011446:Prospective Studies