British Journal of Obstetrics and Gynaecology
Obstetric practice and faecal incontinence three months after delivery
Introduction
Faecal incontinence in women is known to be related to childbirth1, but its relationship with particular obstetric factors is less well known. There is increasing evidence that instrumental delivery is a risk factor2., 3., 4., 5., but the effects of the type of instrument used, forceps or vacuum extraction, are not known. Sultan et al.2., 3. found anal sphincter defects and symptoms of anal incontinence to be more common after forceps delivery and not after vacuum extraction, but the patients were selected by agreeing to undergo anal investigations and numbers were too small to draw conclusions on the relative effects of instrument type. MacArthur et al.4, in a larger study, found that an increased risk of new postpartum incontinence of stool was independently associated with both forceps and vacuum extraction, but since the latter was infrequently practised in the study maternity unit, the number of vacuum deliveries was too small.
To date, therefore, no study has been able to provide evidence on whether forceps or vacuum extraction should be the instrument of choice to reduce the risk of faecal incontinence. Similarly, adequate evidence to support the generally presumed protective effect of caesarean section delivery in relation to symptoms of faecal incontinence is unavailable.
This paper reports on the relationship between faecal incontinence at three months postpartum and maternal and obstetric characteristics, especially mode of delivery, among primiparous births in a large multicentre study.
Section snippets
Methods
All women who were delivered during one year (1993/1994) in three maternity units, in Dunedin (New Zealand), Aberdeen (Scotland), and Birmingham (England) were sent a postal questionnaire at three months postpartum to assess the prevalence of urinary and faecal incontinence. Those with urinary stress incontinence were asked to take part in a randomised controlled trial of the effects of an intensive pelvic floor exercise programme, (reported elsewhere)6. In addition to the questions on urinary
Results
Questionnaires were returned by 7879 of the 10,989 women who had delivered during the study period, a response rate of 71.7%. Casenote data were also available for the non-respondents. Comparisons with the respondents showed that non-respondents were more likely to be under 25 years (39.8% cf 23.2%), multiparous (65.4% cf 55.0%) to have had a spontaneous vaginal delivery (74.0% cf 69.3%) and an intact perineum (56.4% cf 42.6%). There were no other differences in obstetric factors. There was
Discussion
This study has shown that faecal incontinence reported at three months postpartum was significantly more likely to be associated with forceps delivery than with spontaneous vaginal delivery, but was not significantly associated with vacuum extraction. Caesarean section delivery was negatively associated with symptoms, although this was marginal.
This is the first study of childbirth-related faecal incontinence with large enough numbers to provide acceptable evidence that faecal incontinence is
Conclusion
The lack of a standard definition or classificatory system for post-obstetric faecal incontinence has led to various forms of questioning, which in turn affects incidence and prevalence estimates. The primary emphasis of this study as a whole was on urinary incontinence6 so questions on anal incontinence were less detailed. In particular our form of questioning, which was similar to that used in other studies16, did not specify faecal urgency, nor ask about symptom onset. To take account of the
Acknowledgements
The study was funded by a grant from Wellbeing UK. The authors would like to thank Ms J. Cook, Ms J. Harvey, Ms A. McDonald and Ms A. M. Rennie, who were involved in collecting and processing the data. Thanks also to all the women who took part.
References (20)
- et al.
Anal sphincter trauma during instrumental delivery
Int J Gynecol Obstet
(1993) - et al.
Occult anal sphincter trauma following randomised forceps and vacuum delivery
Int J Gynecol Obstet
(1998) - et al.
Caesarean delivery and anal sphincter injury
Obstet Gynaecol
(1998) - et al.
Effect of second vaginal delivery on anorectal physiology and faecal continence: a prospective study
Lancet
(1999) Faecal incontinence. Childbirth is responsible for most cases
BMJ
(1993)- et al.
Anal sphincter disruption during vaginal delivery
N Engl J Med
(1993) - et al.
Faecal incontinence after childbirth
Br J Obstet Gynaecol
(1997) - et al.
Obstetric events leading to anal sphincter damage
Obstet Gynecol
(1998) - et al.
Postnatal incontinence: a multicentre randomised controlled trial of conservative treatment
Urodynamics
(1997) - et al.
Comparison of long term problems following childbirth in Asian and Caucasian women
Br J Gen Pract
(1993)