Long-term complications of caesarean section. The niche in the scar: a prospective cohort study on niche prevalence and its relation to abnormal uterine bleeding
Article first published online: 26 DEC 2013
© 2013 Royal College of Obstetricians and Gynaecologists
BJOG: An International Journal of Obstetrics & Gynaecology
Special Issue: Management of pregnancy after caesarean section
Volume 121, Issue 2, pages 236–244, January 2014
How to Cite
Long-term complications of caesarean section. The niche in the scar: a prospective cohort study on niche prevalence and its relation to abnormal uterine bleeding. BJOG 2014;121:236–244., , , , .
- Issue published online: 26 DEC 2013
- Article first published online: 26 DEC 2013
- Manuscript Accepted: 29 SEP 2013
- Abnormal uterine bleeding;
- caesarean section;
- caesarean section scar;
- postmenstrual spotting;
To study the prevalence of niches in the caesarean scar in a random population, and the relationship with postmenstrual spotting and urinary incontinence.
A prospective cohort study.
A teaching hospital in the Netherlands.
Non-pregnant women delivered by caesarean section.
Transvaginal ultrasound (TVU) and gel instillation sonohysterography (GIS) were performed 6–12 weeks after caesarean section. Women were followed by questionnaire and menstruation score chart at 6–12 weeks, 6 months, and 12 months after caesarean section.
Main outcome measures
Prevalence of a niche 6–12 weeks after caesarean section, using TVU and GIS. Secondary outcomes: relation to postmenstrual spotting and urinary incontinence 6 and 12 months after caesarean section; and niche characteristics, evaluated by TVU and GIS.
Two hundred and sixty-three women were included. Niche prevalence was 49.6% on evaluation with TVU and 64.5% with GIS. Women with a niche measured by GIS reported more postmenstrual spotting than women without a niche (OR 5.48, 95% CI 1.14–26.48). Women with residual myometrium at the site of the uterine scar measuring <50% of the adjacent myometrial thickness had postmenstrual spotting more often than women with a residual myometrial thickness of >50% of the adjacent myometrial thickness (OR 6.13, 95% CI 1.74–21.63). Urinary incontinence was not related to the presence of a niche.
A niche is present in 64.5% of women 6–12 weeks after caesarean section, when examined by GIS. Postmenstrual spotting is more prevalent in women with a niche and in women with a residual myometrial thickness of <50% of the adjacent myometrium.