FRCA Notes

Uterine Inversion

This ultimately rather rare condition is included as it is a cause of major obstetric haemorrhage and has been a cause of maternal mortality in previous CEMACH (now MBBRACE) reports.

Resources

  • Uterine inversion is a rare (1 in 3,500 - 20,000) obstetric emergency characterised by the uterus inverting ± prolapsing through the cervix or vaginal vault
  • It usually occurs during vaginal delivery, although has been reported during LSCS
  • It usually presents acutely, although can do so 24hrs post-delivery or sub-acutely many days post-delivery
  • Four grades based on the extent of uterine extension into the cervical or vaginal orifice:
    1. First degree: corpus or wall of uterus extends into the cervix
    2. Second degree: corpus of uterus passes through the cervical ring but does not reach the perineum
    3. Third degree: fundus of uterus extends to the perineum
    4. Fourth degree: uterus and vagina invert past the perineum

  • The pathogenesis is not well understood, with multiple associated risk factors
  • In general, risk is increased by abnormalities of:
    • Uterine wall integrity
    • Placentation
    • Uterine muscle strength

Non-modifiable Modifiable
Short umbilical cord Excessive umbilical cord traction
Fundal placental site Inappropriate fundal pressure
Abnormality of placentation Uterine atony
Uterine anatomical abnormalities Manual removal of the placenta
Connective tissue disorders Prolonged labour
Foetal macrosomia or multiple gestation Use of uterotonics prior to placental separation


Recognition

Clinical features of uterine inversion
Vaginal mass
Severe lower abdominal pain
Non-palpable fundus
Profound bradycardia and hypotension
Post-partum haemorrhage
(38%; typically 1-2L)
Haemodynamic shock disproportionate to blood loss
(Due to parasympathetic activation from traction on the uterine ligaments)

Immediate

  • Immediate replacement of the uterus by our obstetric colleagues
    • Immediate manual replacement is successful in 20 - 40% of cases; delayed replacement reduces the success rate due to uterine oedema
    • Stop any uterotonic agents e.g. oxytocin infusion
    • May require uterine relaxation i.e. tocolytics e.g. IV terbutaline 0.25mg | 4g IV Magnesium | 100μg GTN
    • So-called "hydrostatic repositioning" using a Trendelenburg position and warm saline infused into the uterine cavity

  • Treatment of shock and/or major obstetric haemorrhage
    • Wide-bore access
    • Bloods inc. FBC, U&E, clotting, group and cross-match, VBG and TEG/ROTEM
    • Vasopressors
    • May require atropine to manage profound sympathetic stimulation
    • Blood transfusion (22% of those who had inversion-induced PPH require transfusion)

  • Consider aliquots of alfentanil e.g. 100 - 250μg to help manage pain until more definitive analgesia/anaesthesia can be facilitated (e.g. epidural top-up, GA)

Subsequent

  • If immediate, manual replacement of the uterus fails, will require attempted replacement under GA
  • If manual replacement under GA fails, surgical intervention is required i.e. laparotomy
  • Uterotonics should be administered post-replacement to prevent recurrence of inversion
  • Antibiotic prophylaxis is required due to high incidence of endometritis