caesarean scar niche/isthmocele and fibroids Flashcards
Definition (international Niche Taskforce) and incidence
An indentation at the site of the caesarean scar with a depth of at least 2mm and visible by means of a TVUSS.
Prev definition used 1mm.
It is a myometrial defect that forms because of imperfect healing.
~50-60% of women with a history of a caesarean section will have a niche.
Associated symptoms
Asymptomatic
Postmenstrual spotting.
Prolonged menses.
dysmenorrhoea and chronic pelvic pain.
Vaginal discharge.
May also cause secondary infertility.
Theoretical impact on fertility
Accumulation of blood, mucus and fluid in the niche
Impaired myometrial contractility
Can lead to:
Impaired sperm migration and viability
Hostile uterine environment for implantation
Change the microbiome/cause chronic endometritis or inflammation
Evidence of impact on secondary infertility.
CS reduced probability of a subsequent pregnancy by 10% relative to a vaginal birth but none looked specifically at uterine niche.
Retrospective study showed women undergoing their first IVF cycle reported significantly lower live birth rates in those with a previous CS cf a previous vaginal birth.
Retrospective study meta-analysis in F&S November 2023 -
P - Women undergoing IVF cycle
I - Isthmocele
C - Those with a CS without isthmocele and those with a vaginal birth
O - Isthmocele associated with a lower live birth rate than both women with a previous CS without isthmocele and those with a vaginal birth
Results more significant for those who have intra-cavity fluid, if no ICF seen then results were similar to that of no isthmocele
Risks associated
Obstetric:
Casearean scar ectopic
Placenta praevia, accreta, increta and percreta
Scar dehiscence
Uterine rupture
*secondary infertility
Options for management
Nil/conservative
Medical management - mentrual suppression
Surgical repair -
- Hysteroscopic
- Laparoscopic
- Vaginal
- Laparotomy
Hysterectomy
Risk factors for developing a CSD
increasing number of CS
Longer duration of labour
Dilatation beyond 5 cm
Peripartum infection
Increased BMI
Low versus high hysterotomy
Fibroids - indication for myomectomy in infertile women (RANZCOG guideline)
Fibroid size, number and location within the uterus may impact on the utility of myomectomy, and this will need to be considered in the management plan for an individual patient.
The indications for myomectomy in infertile women may be summarized as follows:
* Infertile women and those women undergoing ART who have a demonstrated SM fibroid(s).
* Infertile women with symptomatic fibroid(s), such as heavy vaginal bleeding or pressure symptoms, even though trial evidence does not show clear fertility benefit, the presence of symptoms may justify the intervention.
* Couples presenting with multiple failed cycles ART where the female partner has IM fibroids.
Treatment that should only be done in a research setting
- Uterine artery ligation (temporary or permanent)
- Uterine artery embolisation
- Magentic resonance guided focused ultrasound surgery (MRgFUS)
- Myolysis - application of an energy source directed at the fibroids intending to stop blood flow and cause necrosis whilst not damaging the surrounding tissues (laser myolysis or cryomyolysis are examples)
- Radio-frequency ablation
Medical management of fibroids in the context of research setting
Delays efforts to conceive and not recommended.
Can be considered for:
Short term use of GnRH analogue considered for preoperative correction of anaemia or short term reduction in fibroid volume.
Ulipristil acetate is not recommended due to the risk of significant adverse effects (liver failure)
FIGO classification system for AUB in reproductive years
PALM COEIN
Polyp
Adenomyosis
Leiomyomoa (submucous and other)
Malignancy and hyperplasia
Coagulopathy
Ovulatory dyfunction
Endometrial
Iatrogenic
Not otherwise classified
FIGO classification for leiomyoma
Combination of TVUS and TA USS to identify leiomyomas
Subclassification requires determination of relationship of the endometrium with the leiomyoma (contact or not) - done with TVUS, contrast sonohysterography, hysteroscopy or MRI.
Tertiary subclassification requires the clinican to clarify the relationship of the leiomyomas with the endometrium, endometrial cavity, myometrium and uterine serosa.
Proposed MoA for fibroids affecting fertility.
Thicker capsule - A capsule that surrounds the fibroid can be considered a separate entity. This pseudocapsule consists of compressed
myometrium and contains nerves. An increasein pseudocapsule
thickness may increase the number of neuroendocrine fibers,
influencing muscle contractility and uterine peristalsis.
Cochrane review 2017 GnRHa pretreatment prior to surgery for uterine fibroids
GnRHa resulted in:
reduction in uterine and fibroid volumes.
Increase in preoperative Hb
Resulted in higher rate of adverse events (hot flushes etc)
Hysterectomy - reduced operative time, less operative blood loss, fewer blood transfusions, fewer postoperative complications.
Myomectomy - reduced intraoperative blood loss
Note: Whether pretreatment prior to IVF for intramural fibroids improves LBR has not be studied.
Cochrane 2020 Surgical treatment of fibroids for subfertility.
four RCTs with 442 participants.
Very low-quality with the main limitations being due to serious imprecision, inconsistency and indirectness.
There is limited evidence to determine the role of myomectomy for infertility in women with fibroids as only one trial compared myomectomy with no myomectomy.
