Wound complications and niche after caesarean section

Definition

Niche syndrome

• Definition: a defect of the anterior uterine wall at the caesarean scar with thinned myometrium and fluid collection.
• Cardinal symptom: postmenstrual spotting lasting days — blood collects in the niche and drains late.
• Other complaints: chronic pelvic pain, dysmenorrhoea, secondary infertility.
• Work-up: transvaginal ultrasound, plus sonohysterography or hysteroscopy if needed.

• A caesarean scar niche (isthmocele) is an indentation at the site of the caesarean scar with a depth of at least 2 mm.

Classification

• Wound healing disorders after caesarean section comprise superficial infections, wound dehiscence and fluid collections (seroma, haematoma) at the wound site.
• Niches are subclassified as simple, simple with one branch, and complex with more than one branch.

Occurrence & epidemiology

Epidemiology

• Wound healing disorders affect about 3 to 15 per cent of women after caesarean section.
• Niches are frequently detectable on ultrasound, more often with gel or saline contrast than with plain transvaginal sonography.

Aetiopathogenesis

Aetiology and risk factors

• Risk factors for wound complications include young age at childbirth, smoking, obesity, arterial hypertension, diabetes, chorioamnionitis, increased intrapartum blood loss, prolonged rupture of membranes and emergency caesarean section.

Clinical features

Clinical features and complications

• Obese women have an increased risk of wound complications such as haematomas, seromas, abscesses, dehiscence and wound infections.
• Niches are associated with abnormal uterine bleeding, dysmenorrhoea, complications in subsequent pregnancies and possibly subfertility.

Diagnosis

• The niche is examined with transvaginal ultrasound with or without gel or saline contrast, MRI or hysteroscopy; length, depth, residual and adjacent myometrial thickness and width are measured.

Keep learning in the app

Further reading (selection)

1. Jordans IPM et al.: Sonographic examination of uterine niche in non‐pregnant women: a modified Delphi procedure (Ultrasound Obstet Gynecol 2019, PMC)
2. DocCheck Flexikon, Isthmozele

Cross-references