The 2004 Landon study in the NEJM (12/2004) is a very good source for UR information. It included nearly 18,000 that had a TOL (trial of labor which may or may not lead to a successful VBAC). The overall rate of UR was 0.7% which translates into 124 uterine ruptures in that group of nearly 18,000. Only 2 of the babies died following a uterine rupture. Keep in mind, the group included women having a TOL after 1, 2, 3 and 4 c-sections. It also included women who classical, invert T and J incision as well as the low tranverse incision (which is most common and considered the safest for a TOL). About 25% of the women in the TOL group had their labors induced (with prostoglandins or pitocin) and/or augmented with pitocin which also increases risk of uterine rupture. About 25% of the women in the TOL group were less than 2 years from their previous c-section. Clearly, there were many other potential risk factors that could come into play here with the risk of UR.
According to this study :
The absolute risk of neontal death is 0.08% with a TOL vs 0.05% in an ERCS; stated otherwise, the risk of neonatal death is 1 in 1250 babies with a TOL vs 1 in 2000 with an ERCS .
The absolute risk of the mother’s death was 0.04% with an ERCS cs 0.02% with a TOL; stated otherwise, 1 in 2500 mothers will die due to an ERCS vs 1 in 5000 mothers will die with a TOL)
This study also separated out the number of women and the number of UR based on incision type:
- Low transverse incision (n=14,483): 105 ruptures (0.7%)
- Low vertical incision (n=102): 2 ruptures (2.0%)
- Unknown type of incision (n=3206): 15 ruptures (0.5%)
- Classical, inverted T or J incision (n=105): 2 ruptures (1.9%)
- Unclassified (n=2)
It also separated out the number of women based on rates/types of induction:
- Spontaneous labor (n=6682): 24 ruptures (0.4%)
- Augmented labor (n=6009): 52 ruptures (0.9%)
- Induced labor (n=4708): 48 ruptures (1.0%)
- With any prostaglandins, with or without oxytocin (n=926): 13 ruptures (1.4%)
- With prostaglandins alone (n=227): 0 ruptures
- With no prostaglandins (n=1691): 15 ruptures (0.9%)
- With oxytocin alone (n=1864): 20 ruptures (1.1%)
- Not classified (n=496): 0 ruptures
A Breakdown of the number of previous cesareans (obtained from a subsequent study by Landon in Obstetrics and Gynecology 7/2006) (the women who had more than 1 c-section were grouped together and had a UR risk of 0.9% while the women who had 1 VBAC had a risk of 0.7%):
• 16,915 (94.5%) had 1 prior cesarean
• 871 (4.9%) had 2 cesareans
• 84 (0.5) had 3 cesareans
• 20 (0.1%) with 4 cesareans
8 women had an unknown prior # of c-sections
Risks of choosing a a TOL (trial of labor) vs an ERCS (elective repeat c-section):
•More likely to suffer a uterine rupture – the rupture rate in the TOL group was 0.7%; there were no ruptures in the ERCS group, however, women who presented in early labor and did not have a documented intention to labor were excluded so it is possible that women went into labor before their scheduled c-section and ruptured but were excluded from this study’s data
•1.4 times more like to have a uterine dehisence (typically a benign, thin area in the uterus)
•1.7 times more likely to need a tranfusion
•1.6 times more likely to develop endometriosis
•1.3 times more like to have another adverse event such as (broad ligament hematoma, cystotomy, bowel injury, ureteral injury)
•1.6 times more likely for the baby to die (doesn't sound like that big of a difference right? Remember that babies only die in about 2-10% of uterine ruptures according to many studies AND babies do die after c-sections.
Risks of choosing an ERCS over a TOL:
•1.5 times more likely to need a hysterectomy
•2.5 times more likely to have a thromboembolic disease (deep venous thrombosis or pulmonary embolism)
•2 times more likely for mother to die
Risks of a successful VBAC delivery (remember that TOL can end in repeat c-sections) vs an ERCS:
• 1.2 times more likel to need a transfusion
Risks of an ERCS vs a succcessful VBAC:
•3 times more likely for mother to need a hysterectomy
•5 times more likely to have a thromboembolic disease (deep venous thrombosis or pulmonary embolism)
•1.5 times more likely to develop endometriosis
•4 times more likely for mother to die
2 things this study does not address regarding newborns is the incidence of respiratory distress in babies born by elective repeat cesarean which can be quite serious. It also does not address the number of babies that have brain damage as a result of a UR. I want to say the chance of brain damage is about 10-15% when you have a UR but I'd have to double check that. Obviously, UR is very rare but it does happen. When it does happen, UR rarely results in fetal death or brain damage though that too can happen. Babies are usually okay after UR. As far as the mother goes, it doesn't address the decrease in hospitals stay, post partum surgical infection, etc.
You only have minutes to do a c-s in the case of a catastrophic rupture. Most ruptures start small so there is time to do a c-section.
See the first study in this link.
