A Comeback for VBAC?
By Poppy Daniels, MD | May 11, 2011
The year 2010 saw the gathering of national experts at the National Institutes of Health Consensus Development Conference in Bethesda, MD to explore the precipitous drop in vaginal birth after cesarean delivery (VBAC) rates. Subsequently, the American Congress of Obstetricians and Gynecologists (ACOG) released a revision of its Practice Bulletin about VBAC in July 2010. There was increasing awareness that the escalating cesarean rate was having an impact on health care expenditure, morbidity and mortality. Both the NIH Consensus and the ACOG Practice Bulletin concurred that a majority of women with a prior cesarean delivery (CD) could achieve successful VBAC and should be counseled accordingly (1, 20).
The failure of the obstetrics community to face its own shortcomings has been the fallout of overextended physicians, submission to merciless liability pressure, an inflated sense of “ownership” and control over the birthing process, endless documentation demands, and declining reimbursements resulting in pressure to perform more deliveries, surgeries and procedures. Unfortunately, in the case of declining VBAC and rising CD, the consequences are dire. A March 2011 article in the Journal of Maternal, Fetal and Neonatal Medicine utilizing computer modeling indicated that if CD continued at the current rate, by 2020 there will be a 56.2% CD rate, resulting in an additional 6236 placenta previas, 4504 placenta accretas, and 130 maternal deaths annually (28). If such a dismal outlook is to be avoided, those directly involved with birth must begin to focus on real solutions by exploring three main topics in regard to supporting VBAC: pregnant woman, provider and proviso.
Discussions about a woman’s desire for VBAC are preferably begun during the pre-pregnancy period, as a focus on general wellness increases the likelihood of success and begins a proper informed consent discussion. Such an approach allows for logistical planning without the constraints of an impending birth. Addressing obesity is essential as women with a BMI of 30 kg/m2 have significantly lower rates of successful VBAC (16). Efforts should be made to optimize weight, blood pressure, blood sugar, and iron stores as well as educate the patient about proper diet (30). Pre-pregnancy is the best time for folate supplementation and identifying important vitamin/mineral deficiencies. Recent research has associated low Vitamin D levels with higher rates of preterm birth (29) and pre-eclampsia (2). Low magnesium is a common cause of hypertension; most clinicians do not screen for it and when they do it is inaccurate serum magnesium (25). Hormonal imbalances such as commonly seen with polycystic ovarian syndrome, infertility, and recurrent miscarriage should be identified and treated. Normal thyroid, liver and kidney function should be documented as many seemingly healthy young women have multiple problems that could be addressed before becoming pregnant.
Comprehensive perinatal health can be achieved by taking direction from the midwifery model care which clearly outpaces the traditional obstetrical model in regards to time and attention to nutrition and specific guidance for dietary choices. Some evidence suggests that a low glycemic/higher protein (not low carbohydrate) diet can improve outcomes and limit excessive weight gain in pregnancy (9), defined as 40 pounds or higher. Excessive weight gain is more likely to decrease VBAC success than obesity alone (16). Reassessment of previously identified medical problems and vitamin/mineral deficiencies should be undertaken during the course of pregnancy, as frequently as necessary. Often, the routine prenatal panel is simply not complete enough to adequately assess a pregnant woman’s health. I personally advocate for progesterone levels in the first trimester for any patient at risk for progesterone deficiency as normal serum levels are established (15). Must we wait for a preterm birth to occur before offering progesterone therapy (preferably bioidentical rather than synthetic progestin) to at risk women? Evaluation of the placenta by ultrasound should be conducted although high sensitivity and specificity for prediction of accreta is lacking (10).
Mindset and expectations of the pregnant woman are vital to identify early in the course of VBAC discussion (31). Articles by Pang and Fenwick explored women’s feeling about childbirth based on their first pregnancy experience (13, 23). Women who had an emergency CD were more likely to desire a vaginal birth with their next pregnancy, while women who had a scheduled CD were more likely to desire elective repeat cesarean delivery (ERCD). Women who had an unexpected CD were more likely to reframe their idea of normal birth. These women tended to think of themselves as unable to birth or “high risk.” A woman may be deemed selfish for valuing the birthing process at all rather than focusing only on the outcome of a “healthy baby.” A fear factor can be introduced by the provider, anxious family members or television programs. Language is critical as some women reported being counseled that they had “a high risk of splitting open with VBAC” or were asked “do you want a dead baby and a live mother?” Friends and family members are often fond of telling pregnant women horror stories of birth gone wrong. Highly dramatized birthing shows perpetuate fear of the birthing process and “rescue” by the valiant obstetric team. After all, what could be more boring in our sensation-driven media than a normal, uncomplicated vaginal birth?
Ideally, true informed consent should begin with asking non-pregnant women with history of prior CD about her desires for subsequent childbearing and delivery methods. Milne explored the use of a decision board presenting factual information to non-pregnant women regarding the risks and benefits of vaginal birth versus CD (19). The study found that some women who were unsure about mode of delivery for a subsequent pregnancy, became more certain after a neutral presentation of information. Such a model has been replicated online with “A Woman’s Guide to VBAC” which is provided by Birthing with Confidence, an online community created by Lamaze International. The intent of such information should not necessarily be to persuade a woman to pursue VBAC but rather to give her adequate knowledge with which to help her decision-making process regarding the best birth method for her. In the interest of further facilitating the informed consent process, I propose creating a neutral multidisciplinary group involving physician, midwife and perhaps other professionals who would provide several perspectives with which to help inform the non-pregnant or pregnant woman, a process called “the VBAC Evaluation.” Such an evaluation would take into consideration a patient’s prior birth histories in the context of an individualized medical assessment which may include clinical pelvimetry, evaluation of emotional experiences in response to those births, exploring social support and logistical factors, and networking to provide referral to the appropriate providers and facilities. Potential VBAC candidates should be given access to the recent NIH Consensus Statement and ACOG guidelines. Many women have been able to find helpful resources through social media, blogs, and support organizations like the International Cesarean Awareness Network (ICAN) and Childbirth Connection.
Previous ACOG Practice Bulletins about VBAC recommended that emergent delivery be “immediately available.” That proposal was taken to mean that 24 hour in-house obstetrics and anesthesia were required, an impossibility for many rural and even some metropolitan hospitals. Hospitals began to decline to offer VBAC, termed “VBAC bans.” The revised July 2010 Practice Bulletin now suggests that VBAC be offered in facilities “capable of emergent delivery.” Unfortunately, many hospital administrators feel the staffing and anesthesia availability necessary to support VBAC are lacking in their facilities. Many physicians recall when insurance companies were forcing women to have VBACs for cost reduction reasons, a time when risk factors for VBAC patients were poorly understood (e.g. the use of prostaglandins for induction). The rise of uterine rupture resulted in more malpractice suits and higher insurance premiums. Facility risk management may not be aware of the recent change in guidelines for supporting VBAC. Individual provider malpractice concerns are valid in light of the litigation climate for obstetrics (26). Efforts at tort reform have been slow but promising; two types of tort reform which may increase VBAC rates include caps on non-economic damages and pretrial screening panels (20). Provider reluctance to support VBAC may not just be about malpractice. Coleman sent out questionnaires to OBs and found that while 98% of them reporting knowing the risks and benefits of VBAC, only 61% reported feeling competent in determining which patient would have a successful VBAC (6). One wonders how many busy OBs have read the most recent Practice Bulletin, let alone the 2010 NIH Consensus. Administrators and providers are also concerned about public perception. Socol noted that “budgets and balancing resources are important factors but pale in decision making, compared with the ill publicity and medicolegal risk associated with an untoward outcome.” (27)
Private practice OBs are often juggling a busy outpatient practice, full surgery schedule and call. Time management concerns have contributed to the rising rates of elective induction, especially in community hospitals (3). Obstetrical hospitalists or laborists allow a physician to be dedicated to one location and have a more neutral view of patients, an approach which is off-putting to some women who prefer the continuity of their prenatal care provider. Laborists and university hospital attendings are more likely to have their malpractice premiums paid by the hospital. A private physician paying high premiums can perhaps feel a greater pressure from hungry trial lawyers appealing to emotionally charged obstetrical cases. In the current climate of increasing overhead costs and declining reimbursements, private physicians have the pressure of productivity, whereas a salaried laborist may not feel pressure to speed labors along or perform more cesareans.
A hospital-based midwife would seem to be an ideal candidate for a laborist position. Many metropolitan or university hospitals currently do include both physicians and midwives either in a parallel or completely collaborative model. A true collaborative program should allow hospital-based midwives to manage low-risk VBACs, particularly since these women may have prolonged labors usually associated with a primiparous patient. Whether a resident trains in a university or community hospital will obviously impact how such a physican will practice after graduation. University hospitals have higher risk patients and tend to have stricter adherence to guidelines for medical-indicated induction. Elective induction rates are higher in community hospitals. The combination of hospital, provider and nursing culture will influence a particular center’s VBAC rate. Although the impression may be that metropolitan or high volume hospitals would have higher VBAC rates, they may have more hospital policy or risk management pressure than smaller or rural hospitals.
Central to the VBAC discussion should be an understanding of the reason for the primary CD. True cephalopelvic disproportion is frequently considered to be a retrospective diagnosis and efforts should be made to adequately assess pelvimetry by an experienced clinician. Labor dystocia is defined as a failure to dilate or descend, but how frequently is it simply a failure to wait (24)? Too many women are undergoing CD in the latent phase of labor and strict adherence to Friedman’s curve has been called into question (33). Whether labor was induced or not is a key consideration, given that elective induction is associated with a two-fold increased risk of CD (11). If pregnancy complications or medical conditions were the reason for surgical delivery, efforts can be made to optimize these situations. Certainly VBAC should be discussed with women who had a non-recurring reason for CD, like breech presentation.
Certain factors may cause a woman to have a lower chance of successful VBAC and should be discussed but should not automatically preclude a trial of labor. These factors include a low Bishop score, obesity, inter-pregnancy interval of 18 months or less, single-layer uterine closure at prior CD, large for gestational age baby, and low volume hospitals (14, 17). Some conditions once considered contraindications should be assessed individually including more than one CD, beyond 40 weeks gestation (5), prior low vertical uterine incision, macrosomia, unknown scar, or twins (1).
Hospitals and providers must focus on the elimination of elective induction as well as working to reduce the number of early term medical inductions, due to the increased risk of neonatal respiratory complications, NICU admission, and extended hospitalizations (8). Community hospitals in particular may not want to override provider autonomy, but administrators should mandate that elective induction never be done before 39 weeks gestation. Although some mothers are informed and educated about the risks of the rising cesarean rate, many women are not aware of them and are influenced by their own experiences and those of friends and family who may not be upset about CD.
If induction is necessary, than the need for judicious use of induction agents must be stressed. While the highest risk of uterine rupture is with the use of misoprostol (Cytotec, prostaglandin E1), all prostaglandins are probably best avoided. A ripe cervix or high Bishop’s score increases the likelihood of successful VBAC but mechanical dilation with a transcervical Foley catheter may be acceptable. Pitocin inductions should be start low and “go slow.” Recent studies suggest that high dose pitocin protocols are associated with higher rates of uterine rupture (4).
There is no evidence-based indication for continuous monitoring in all VBACs although it is recommended for those receiving induction agents. There is also no evidence for the need for internal fetal monitoring or intrauterine pressure catheters. Although some hospital policies require continuous electronic fetal monitoring (EFM), as long as labor is progressing and fetal heart tones are reassuring, intermittent monitoring may be acceptable. Intermittent monitoring is more commonly practiced by midwives, as continuous EFM tends to make OBs feel better.
Common labor practices such as EFM and IV hydration render a woman relatively immobile which increases the risk of labor dystocia. As long as a woman is not receiving induction agents or considered otherwise high risk, there should be consideration given to a Heplock rather than automatic IV fluids. In general obstetrics, there has been a movement toward allowing women to have more fluids and even food in early labor. Such practices generally cause distress for anesthesiologists, although the chance of aspiration in low risk women is small (12). In the hospital setting, the case of leniency for low risk patients, at least for fluids should be considered.
Continuous labor support as exemplified by doulas has been shown to be associated with lower CD rates (18). A nurse’s support is key for aiding in a successful VBAC so communication of mom’s desires for a vaginal birth should be communicated early. Just as the attitude of “the patient has a birth plan, therefore will have a CD” should be discouraged, so should the attitude that “the patient wants a VBAC, but she can’t or won’t.” Inviting the nurse to be part of the team approach should enable an easier birth experience and avoid hostility between the parties present. The doula should not assume an adversarial role in the birth or make the nurse feel that she or he is an outsider or vice versa. Epidurals are associated with higher rates of operative delivery and many women are unaware of this higher risk (22). Without induction, and with trained labor support and mobility, a woman may be able to delay or avoid an epidural. A dense epidural can also decrease mom’s ability to push effectively.
An overriding theme in supporting VBAC should be to respect the process and respect the scar. If this is a woman’s first vaginal birth, she may have a very prolonged labor similar to a primiparous patient. We must avoid practicing defensive medicine, as we cannot prevent poor outcomes by attempting to circumvent them with surgery. Hospital administrators, staff or family members should not be allowed to “pressure the process” because of their own expectations or fears. Just as we cannot overmedicalize the birthing process, we must recognize that the woman with a scarred uterus carries a higher level of risk and that risk must be respected so that we can achieve the best outcomes.
SOLUTIONS TO THE “VBAC PROBLEM”
Reducing the primary CD rate will begin with efforts to eliminate elective induction. Even those hospitals which continue to allow them should have very strict criteria. Women with low risk medical indications for induction such as oligohydramnios and mild preeclampsia should be closely monitored and not automatically induced. For those who require inductions, there should be adherence to low dose Pitocin protocols with upper limits consistent with the literature recommendations. The incorporation and support of hospital-based midwifery and doula programs will enable low risk pregnant women to be able to receive one-on-one care and support, which will reduce the number of operative deliveries. Collaboration between physicians and midwives will enable women to receive the benefits of both approaches and will create a cohesive network for promoting the best outcomes. A multidisciplinary “VBAC Evaluation” would enable a woman to have a true sense of whether she would be a good VBAC candidate, based not only on her medical and obstetric history, but other important issues like fears, support, and availability of services near her. Tertiary care hospitals who have higher rates of VBAC should consider positioning themselves as VBAC referral centers (21). Since such centers have immediately available resources and specialists that many hospitals do not have, they stand to be able to meet the needs of women who desire VBAC, even if travel is necessary achieve it. Consideration should be given to a laborist/midwife collaboration for provider staffing. Women should not be forced into homebirth because they are unable to find a VBAC supportive provider. The ACOG and NIH guidelines should be widely disseminated among both potential VBAC candidates and clinicians alike. Although it may take time for evidence-based changes to become incorporated into clinical practice, the time seems ripe for bringing VBAC to the forefront. Many women are active in social media and have become involved in organizations like ICAN; however, a focus must be on making a greater impact on the majority of pregnant and potentially pregnant women who are not connected to these forums. Childbirth educators, breastfeeding support groups, “mommy” blogs and websites, advertising of doula and midwifery services are all opportunities to raise awareness.
While the near universal disappearance of VBAC is a multifactorial problem, the need to support vaginal birth as an essentially natural process, albeit potentially complicated one, is a concept with which many OB/GYNS are unfamiliar. Midwives understand that most healthy, low-risk women are able to birth their babies without medical intervention. Even women with a scarred uterus who are managed properly can avoid them. Sometimes those in the natural birth community accept a higher level of risk because of a distrust of the medical system. The goal should be to bring the best of both worlds together in a collaborative way to provide the best birth for each woman, in whatever form that may be. Working together can only help make birthing better for all women.