Introduction
Anal incontinence is a source of distress for patients, with a major
impact on sexual health 1 and quality of life2,3. It is a frequent symptom 4,
with a prevalence 14.8% among women in a population-based study in the
United States 5. Obstetrical anal sphincter injuries
(OASIS) are visible third or fourth-degree perineal lacerations,
reported in 2 to 12% of vaginal deliveries 6,7.
Occult anal sphincter lesions, which are not noticed at the time of
delivery, can be detected by systematic endoanal ultrasonography in up
to 27% of women after their first vaginal delivery8.
Anal sphincter lesions may result in anal incontinence in 9% of women7,8. Instrumental delivery is the most important risk
factor for anal incontinence, with anal sphincter lesions reported in up
to 63% to 82 % of forceps deliveries 8 and anal
incontinence in 23 % 8. Post-delivery anal
incontinence decreases over time, but it contributes to anal
incontinence in the long term 9.
In case of anal sphincter lesions at the first delivery, cesarean
section (CS) is often discussed for subsequent deliveries, with the
purpose of protecting anal function. However, recommendations differ
between countries and centers. 10 1112. Current ACOG guidelines state that women with a
history of OASIS who are asymptomatic and without any evidence of
sphincter compromise may be allowed to have a vaginal delivery, however
it is reasonable to perform a cesarean delivery based on patient
request13. To date there is no high-level evidence
from a randomized trial to inform the decision13 . The
potential benefit needs to be proven, since CS is a major surgical
procedure with risks for the mother and infant 14,
including maternal morbidities and mortality at the time of the surgery
and during subsequent pregnancies15. In recent
retrospective cohort studies comparing CS versus repeat VD in women with
a history of anal sphincter lesions, no significant difference was found
in the incidence of anal incontinence 9,16. However,
the limitations were the potential indication bias inherent to
observational studies and the retrospective design. The potential
benefit of prophylactic CS on urinary incontinence, quality of life and
sexual functions also must be addressed, as they deeply impact quality
of life 2,17. Our main purpose was to evaluate whether
anal incontinence could be prevented by planned CS for the second
delivery, in women with asymptomatic anal sphincter disruption after the
first delivery.