Midwifery & Women’s Health at Elmhurst Clinic
VBAC BUZZ!
In March 2010, the National Institutes of Health held a 3-day Consensus Conference in Washington DC, examining the current situation in maternity care regarding VBAC’s, which have diminished considerably in number over the past 10-15 years. Read the consensus preliminary report, which can be found at http://consensus.nih.gov/2010/vbacstatement.htm.
Why VBAC?
According to the American College of Obstetricians & Gynecologists (ACOG), there is good evidence that most women who have had a low transverse (horizontal) uterine incision and no other risk for vaginal delivery can be offered a trial of labor for vaginal birth on the following pregnancy.
The success rate for VBAC is shown to be from 60-80%. Some things can decrease success, such as C-section for a large baby, maternal obesity, postdates pregnancy, and last delivery less than 19 months prior to estimated due date.
The midwives work in consultation with their supportive collaborating physicians to provide this service to certain clients who meet criteria. It is also possible for some mothers choosing to VBAC to use the alternative birthing center.
Risks and benefits of VBAC and of repeat Cesarean are reviewed with each woman individually because while VBAC is a good option for many women, it is not recommended for ALL women.
VBAC- Trial of Labor (TOL) vs. Elective Repeat Cesarean Delivery (ERCD)
Aside from the obvious benefits of a quicker recovery from childbirth, shorter hospital stay and less risk from abdominal surgery-- much of what is beneficial from VBAC is prevention of complications for the NEXT pregnancy.
There is an association between ERCD and subsequent abnormal placenta position and growth. The incidence of placenta previa (placenta covering the cervix), placenta accreta (growth of the placenta into the uterine muscle) all significantly increases in women with each additional cesarean delivery occurring. By the third pregnancy delivered by cesarean, the risk of previa is 3,000 per 100,000 and risk of accreta is 2,400/100,000. Placental abruption (placenta separates before birth) is also increased in women with previous cesarean delivery.
All of these placental problems pose risks to the baby & mother: risk of bleeding, impaired growth of baby, loss of pregnancy (stillbirth) or uterus (hysterectomy).
Additionally, maternal mortality may be decreased by a VBAC-TOL. Overall estimates of maternal death number 3.8/100,000 for women who undergo a trial of labor versus 13.4/100,000 for ERCD. This may be a result of fewer blood clots in the veins (deep vein thrombosis).
The most talked about risk of VBAC-TOL is uterine rupture. This is where the previous scar on the uterus opens or separates. If this happens, it can result in major blood loss and require emergent delivery by cesarean. Clearly this can put the life of the baby at risk. Thankfully, studies have shown this to be a very rare event.
Uterine rupture occurs around 778/100,000 times for women having a TOL (less than 1%). Induction of labor after 40 weeks may increase this risk. Between 14 - 33 % of women will need a hysterectomy with uterine rupture.
In terms of fetal death and neonatal mortality (these are deaths between 20 weeks pregnant to 28 days of life after birth), TOL is associated with a rate of 130/100,000 (0.13%) compared to having an ERCD which is 50/100,000 (0.05%). It is important to understand that the risk of fetal/infant death in the TOL group is similar to the risk of any first-time laboring woman’s infant in the general population.
There are no reported maternal deaths due to uterine rupture.
Having a ERCD decreases the risk of uterine rupture to 22/100,000, but does not eliminate it. Although cesarean delivery has been studied in conditions such as chronic pain, ectopic pregnancy, stillbirth, and infertility, no studies are conclusive.
It is generally recognized that an increasing number of abdominal surgeries is associated with the following complications: significant adhesions (internal scar tissue), operative complications at time of ERCD, bowel and bladder injuries, and operative complications during hysterectomy later in life.
Infants born by ERCD may have higher rates of respiratory problems, including respiratory distress syndrome (RDS), transient tachypnea of the newborn (fast respirations), and need for oxygen and ventilator support than do infants born by VBAC. There is a lack of data to determine whether substantial differences in respiratory outcomes occur between ERCD and TOL.
--Excerpts taken from the NIH Consensus Statement on VBAC (2010)
Additional Resources on VBAC:
American College of Nurse Midwives
American College of Obstetricians & Gynecologists
Childbirth Connection
International Cesarean Awareness Network
