Espresso: Uterine Rupture
/What is uterine rupture?
Definition
Spontaneous tearing of the uterine muscles which can lead to expulsion of the fetus into the peritoneal cavity
In the literature, uterine rupture can also incorporate less catastrophic phenomena, like uterine window or asymptomatic scar dehiscence without expulsion of the fetus
Focus today: intrapartum uterine rupture.
The true incidence of uterine rupture across all populations in pregnancy is likely very low.
With no history of surgery, the risk is 1/8000-17,000 deliveries
With one prior low transverse cesarean, the incidence has been reported to be between 0.2-1.5%, though usually quoted as <1%
With two prior low transverse cesareans, the incidence is reported to be between 0.8-3.9%, usually quoted as just over 1%
However, there are things that can modify this risk:
History of prior successful VBAC → reduce the risk of rupture from 1.1% to 0.2%
In other types of incisions such as T-incisions and classical incisions, the rate of rupture can be as high as 4-9%
What are some other risk factors?
By far, the biggest one is previous uterine surgery,
Other risk factors:
Uterine scar presence
Uterine anomalies
Prior invasive molar pregnancy
History of placenta accreta spectrum
Malpresentation
Fetal anomaly
Obstructed labor
Induction of labor with use of prostaglandins
These other risk factors are much less significant than prior uterine surgery/presence of scar
How do I recognize uterine rupture?
Again — only be discussing uterine rupture in labor
There are a few studies looking at thinning of the myometrium on ultrasound, but this is controversial.
It is much more likely that you will encounter uterine rupture at time of labor and birth than during other times
Diagnosis
High index of suspicion - know your patient’s risk factors and be on the lookout for uterine rupture given how catastrophic it can be for both maternal and fetal wellbeing
Some of the classical signs:
Sudden, tearing uterine pain
Vaginal hemorrhage
Cessation of contractions
Destationing of the fetal head
However, these classical signs are actually not necessarily reliable and not always present!
The most reliable presenting clinical symptom is actually fetal distress
One study of 99 patients with uterine rupture showed:
Only 13 patients reported pain and 11 had vaginal bleeding
However, bradycardia or signs of fetal distress (decelerations) were present in the majority.
Ultrasound examination
Not necessarily reliable and if you are truly suspicious of uterine rupture, this should prompt immediate delivery
Why do we need to diagnose uterine rupture promptly?
Maternal complications
Maternal circulatory system delivers 500 cc of blood to the uterus every minute
Uterine rupture increases the risk of hemorrhage, with studies showing that about 50% of cases result in EBL of 2000cc or greater
This can lead to need for blood transfusion, and in more dire circumstances, hysterectomy
Fetal complications
Depends on how quickly the neonate is delivered after recognition of uterine rupture
One study showed a neonatal mortality rate of 2.6%, and increases to 6% if uterine rupture occurs outside of the hospital
Older literature report rates as high as 13%
Many neonates will require resuscitation and admission to the NICU
Management
The best form of management is prevention or setting expectations - ie. counseling
All patients who desires a trial of labor after cesarean section should be counseled about the risks and benefits of TOLAC
Patients should deliver at a location where labor and delivery staff, anesthesia staff, and neonatal staff are available 24 hours in order to facilitate prompt delivery if needed.
Patients who are at high risk of uterine rupture (ie. classical cesarean, T-incision, prior uterine rupture, >2 cesarean sections, history of prior fundal surgery) should be counseled against TOLAC
We did a whole episode on TOLAC counseling back in 2019, so check it out here: https://creogsovercoffee.com/notes/2019/9/22/trial-of-labor
Note that the VBAC calculator we included in those notes is outdated!
There is a new VBAC calculator available that does not include race as a predictor: https://mfmunetwork.bsc.gwu.edu/web/mfmunetwork/vaginal-birth-after-cesarean-calculator
What if it happens? The answer is prompt delivery via cesarean delivery
Urgent delivery - as quickly as possible, but within 30 minutes generally
Patient can be under general anesthesia or if they already have working regional anesthesia, this can also be used
Cesarean delivery should be performed, and if there is a uterine rupture, the neonate can often be delivered via the area of rupture without creating a new hysterotomy
However, if there is just a uterine window, a hysterotomy may be needed
Once the neonate is delivered, pediatrics should be there immediately to facilitate resuscitation
If uterine rupture is confirmed, a full exam of the uterus should be done to assess for other injury
Ie. bladder injury, broad ligament hematoma
If possible, the area of rupture should be repaired
However, if it is not possible to repair the rupture due to significant damage, patient is not stable, or significant hemorrhage, then the next step should be hysterectomy
Follow-up
Debriefing - this should occur with the team who was present for uterine rupture
But also, should discuss with your patient when they are at a place when they can discuss what happened
Counsel patient that if they desire future pregnancy, TOLAC should not be attempted due to increased risk of repeat rupture