|
|
The Following Was taken From; What About Uterine Scar Ruptures? by Nicette Jukelevics, MA, ICCE
What is a uterine scar rupture?
A complete uterine scar rupture is a potentially life threatening condition for both the mother and/or the baby that requires immediate surgical intervention. Fortunately, uterine ruptures from a prior cesarean with a low-transverse scar is a rare event and occurs in less than 1% of women laboring for a VBAC. It is a tear through the thickness of the uterine wall at the site of a prior cesarean incision. The majority of cesarean uterine incisions are low-transverse. The scar form this type of incision is the least likely to rupture in a subsequent pregnancy, labor, and birth.
Uterine ruptures have also been known to occur in some women who have never had a cesarean. This type of rupture can be caused by weak uterine muscles after several pregnancies, excessive use of labor inducing agents, prior surgical procedure on the uterus, or mid-pelvic use of forceps.
When planning a VBAC it is important to determine if the previous low vertical scar has not stretched to the body of the uterus in the current pregnancy. The risk of rupture for a low vertical scar has been reported to be the same as for a low horizontal scar and as high as 7%.
Rarely, a woman may have a classical (vertical) scar in the upper part (the body) of the uterus. This type of incision is used for babies who are in a breech or transverse position, for women who may have a uterine malformation, for premature babies or in extreme circumstances when time is of the essence.
The risk of rupture for this type of scar has been reported to be between 4% and 9%. A classical scar on the thinner and more vulnerable part of the uterus tends to rupture with more intensity and result in more serious complications for mothers and babies. Mothers who have had several children and have a classical uterine scar are at higher risk for uterine rupture.
How often does a cesarean scar rupture occur?
For women who had a prior cesarean birth the rupture can occur at the site of the previous uterine scar. Dozens of studies report that for women who have had one prior cesarean birth with a low-horizontal incision, the risk of uterine rupture is 0.5% to 1.0%. A woman who has had more than one cesarean with a low horizontal incision may have a slightly higher risk of rupture. One study that looked at the risks of uterine rupture for planned VBACs over a ten-year period at a teaching hospital that was often able to perform an emergency cesarean very quickly found the following results:
10,880 Planned VBACs with one prior scar 83% 0.6% 0.018%
1,586 Planned VBACs with two prior scars 76% 1.8% 0.063%
241 Planned VBACs with three prior scars 79% 1.2% 0
(This study included women with breech babies and twins and use of oxytocin.)
What happens if the scar ruptures?
Although uterine scar ruptures for women laboring for a VBAC are rare, the medical response is a rapid cesarean.
The longer it takes to diagnose and respond to a uterine rupture the more likely it is that the baby and/or the placenta can be pushed through the uterine wall and into the mother's abdominal cavity putting women at increased risk for hemorrhage and babies at increased risk for neurological complications and very rarely, death.
Birthing facilities vary in their guidelines and protocols for VBAC and response time to a uterine rupture and other unforeseen complications of labor. Many US facilities have recently determined that they don't have the capability to respond "immediately" in case of uterine scar rupture and are currently denying women the option to labor for a VBAC.
Caregivers who support VBACs say that the focus should be on improving access to quality of care for women who want a VBAC, not on discouraging them because of negative outcomes publicized in high profile medical malpractice law suits.
In the event of a uterine rupture, what are the outcomes for mothers and babies?
The majority of studies report that in the rare event of a uterine rupture, if the labor was carefully monitored, the birth attendant was trained to attend VBAC births, and if the medical response was rapid, mothers and babies usually do well. One study in a large California hospital which had 24 hour emergency coverage reported that outcomes for babies were better when the response time was 18 minutes or less.
Can the risk for a uterine rupture be reduced?
Although it is not possible to predict which women are likely to experience a uterine rupture while laboring for a VBAC, recent studies have suggested that the risk for uterine rupture is higher when:
*Labor is induced with oxytocin, prostaglandin preparations, or misoprostol (Cytotec).
*The prior cesarean incision was closed with a single-layer of sutures (single-layer closure- often done in recent years to shorten the time in the operating room) as opposed to two layers of sutures (double-layer closure).
*Women become pregnant and labor for a VBAC within less than 24 months after a prior cesarean.
*Women are older than 30 years of age.
*Maternal fever was a consequence of a prior cesarean birth.
*A classical uterine incision was used in a prior cesarean birth.
*A woman has had two or more prior cesarean births.
*According to ACOG, prostaglandins for induction of labor in most women with a previous cesarean should be discouraged. Similarly, the SOGC states that misoprostol "is associated with a high risk of uterine rupture and should not be used" when women labor for a VBAC.
Informed Choice-Informed Refusal
Current US health law and medical-ethical guidelines give childbearing women who once gave birth by cesarean the option of laboring for a VBAC or scheduling an elective repeat cesarean. ACOG states that
"it has become clear that patients are entitled to participate with their physicians in a process of shared decision making with regard to medical procedures, tests, or treatments"; Once the patient has been informed of the material risks, and benefits involved ; that patient has the right to exercise full autonomy in deciding whether to undergo the treatment, test, or procedure or whether to make a choice among a variety of treatments, tests, or procedures. In the exercise of that autonomy, the informed patient also has the right to refuse to undergo any of these treatments, tests, or procedures. This election by the patient to forgo a treatment, test, or procedure that has been offered or recommended by the physician constitutes informed refusal."
Women are encouraged to ask questions, gather information, and discuss their concerns with their care providers to enable them to make an informed choice for a VBAC or a repeat cesarean birth.
|
|