1. VBAC should be encouraged in patients with one previous Cesarean Section (C/S) and considered in patients with two previous Cesarean Section (C/S) as long as there are no other contraindications.
2. The benefits of a VBAC are significant as compared to the potential complications associated with a repeat C/S.
3. The recommendation of "once a cesarean, always a cesarean" is not valid and is not supported by the literature.
4. The risk of an Uterine Rupture, which is one of the most serious complications of a failed VBAC, occurs between 0.5-1%.
5. The risk of materal death associated with a uterine rupture is extremely low, reaching almost 0%.
6. The risk of fetal death associated with a uterine rupture is between 3-6%.
7. Current hospital policies either banning VBAC outright or restricting VBAC to a single previous C/S is not supported by the literature and can compromise both the health and well-being of both mother and baby.
8. Current hospital policies requiring a physician to be "immediately available" or "in-house" (in the hospital) during the entire labor process has not been shown to improve the overall outcome of the VBAC delivery and has instead lead to the reduction of routine VBAC deliveries to less than 10%.
9. Proper Informed Consent regarding the VBAC requires that your physician provide information regarding the most current recommendations on VBAC from institutions such as the National Institutes of Health (NIH), the Centers for Disease Control (CDC), the United States Department of Health and Human Services, and the American Congress of Obstetricians and Gynecologists (ACOG).
10. Each repeat C/S increases risks of complications, especially after four C/S and should be discussed especially in women considering having large families.

1. National Institutes of Health (NIH):
   "Given the available evidence, trial of labor is a reasonable option for many pregnant women with one prior low transverse uterine incision."
   https://pmc.ncbi.nlm.nih.gov/articles/PMC2953727/
2. U.S. Department of Health and Human Services (HHS), Agency for Healthcare Research and Quality (AHRQ):
   "VBAC is a reasonable and safe choice for the majority of women with prior caesarean and that there is emerging evidence of serious harms relating to multiple caesareans."
   http://www.ahrq.gov *2013
3. American Congress of Obstetricians and Gynecologists (ACOG):
   "Attempting a vaginal birth after cesarean (VBAC) is a safe and appropriate choice for most women who have had a prior cesarean delivery, including for some women who have had two previous cesareans."
   https://www.acog.org
4. National Library of Medicine:
   Vaginal Birth After Cesarean Section
   "Patients attempting VBAC typically undergo a trial of labor after cesarean (TOLAC), a generally safe practice associated with a 60% to 80% success rate."
   https://www.ncbi.nlm.nih.gov
5. U.S. Department of Health and Human Services:
   Recent trends in VBAC 2018
   "The VBAC rate increased during 2016–2018 overall and for women in their 20s and 30s."
   https://www.cdc.gov/nchs/data/databriefs/db359-h.pdf
6. OBGYN Key - Fastest Obstetric, Gynecology and Pediatric Insight Engine:
   Thickness of the Lower Uterine segment to prevent Uterine Rupture
   "The inclusion of lower uterine segment thickness measurement in the decision of the route of delivery allows a low risk of uterine rupture during trial of labor after cesarean delivery."
   https://obgynkey.com

1. Augmentation of Labor - the intentional increase in contraction frequency or intensity when contractions are already present or dilation of the cervix is occurring in order to hasten the process of labor with the goal of achieving a vaginal delivery.
2. Cesarean Section (C/S) - the delivery of a baby by making a surgical incision through the abdomen and the uterus, thus allowing for the delivery of the baby through these incisions and not through a vaginal approach.
3. Elective repeat Cesarean Section (ERCS) - Planned cesarean delivery in a woman who has had one or more prior cesarean deliveries. The delivery may or may not be scheduled.
4. Home Birth After Cesarean Section (HBAC) - the delivery of a baby vaginally at a home, private residence or domicile, after having delivered previously by C/S.
   • HBAnC - (n) representing the number of previous C/S. ie. If a patient had 3 previous C/S, then HBA3C.
5. Induction of Labor - the provoking or intentional production of uterine contractions in a previously non-contracting uterus in order to cause or "induce" labor with the goal of achieving a vaginal delivery.
6. Labor - physiologic process during which the products of conception (ie, the fetus, membranes, umbilical cord, and placenta) are expelled outside of the uterus.
7. Nulliparous - a woman who has never had a pregnancy go beyond 20 weeks or given birth to a viable, or live, infant.
8. Preterm Labor - the presence of uterine contractions of sufficient frequency and intensity to cause progressive effacement and dilation of the cervix prior to term gestation (between 20 and 37 wk).
9. Preterm Pregnancy - estimated gestational age of a baby below 37 weeks.
10. Placenta previa - a complication of pregnancy in which the placenta grows in the lowest part of the uterus and covers all or part of the opening to the cervix. The risk of placenta previa in the general population is 1/200 pregnancies but more common in women with previous C/S. There are three types of placenta previa:
    • Marginal - The placenta is next to cervix but does not cover the opening.
    • Partial - The placenta covers part of the cervical opening.
    • Complete - The placenta covers all of the cervical opening.
11. Placenta accreta - is a general term used to describe a complication of pregnancy in which there is an abnormally deep attachment of the placenta through the endometrium and into the myometrium (muscle of the uterus). This invasion of the placenta then becomes...
12. Placenta increta - a variant of placenta accreta with deeper penetration into the myometrium than placenta accreta.
13. Placenta percreta - a variant of placenta accreta with complete penetration through the myometrium to the serosa and/or adjacent organs to the uterus.
14. Postterm Pregnancy - estimated gestational age of a baby 42 weeks and beyond.
15. Term Pregnancy - estimated gestational age of a baby between 37-42 weeks.
16. Trial of Labor after Cesarean Section (TOLAC) - term used when a patient attempts a vaginal delivery after a previous C/S. It can either be associated with spontaneous labor or with an induction of labor.
    • TOLAC is the term used when the patient is attempting the Vaginal Birth after Cesarean Section (VBAC).
    • Therefore, a VBAC is a successful TOLAC.
17. Unsuccessful trial of labor - Delivery by Cesarean Section in a woman who has had a trial of labor; sometimes referred to as a "failed" TOLAC.
18. Vaginal Delivery - the delivery of a baby through the vagina, either spontaneously or with the assistance of instruments such as a vacuum or forceps.
19. Vaginal Birth after Cesarean Section (VBAC) - the delivery of a baby vaginally after having had a previous C/S. Also known as a successful TOLAC.
    • VBAnC - (n) representing the number of previous C/S. ie. If a patient had 3 previous C/S, then VBA3C.
20. Water Birth After Cesarean Section (WBAC) - the delivery of a baby vaginally in a water pool or tub after having had a previous C/S.
    • WBAnC - (n) representing the number of previous C/S. ie. If a patient had 3 previous C/S, then WBA3C.

In 1916, Dr. E.B. Cragin delivered an address entitled "Conservatism in Obstetrics" to the Eastern Medical Society of New York in which he coined the phrase "Once a caesarean, always a caesarean."

For most of the twentieth century, doctors followed this dogma believing that once a woman delivered by C/S she should deliver all future pregnancies by repeat C/S. Clinical studies starting the 1960s, however, concluded that this practice was not always necessary.

In 1980, the National Institutes of Health (NIH) Consensus Development Conference Panel questioned the necessity of routine repeat Cesarean Section. After extensive research, the panel made recommendations regarding the VBAC. Their recommendations gave support to the practice of the TOLAC and successful VBAC with a significant rise in the number of attempted VBAC from the 1980s through 1996.

A major turning point occurred in 1996 with a study published in The New England Journal of Medicine (MacMahon et al, 1996) which concluded that a vaginal delivery after previous C/S (VBAC) was associated with an increased maternal complications as compared to the Elective Repeat Cesarean Section (ERCS).

The American College of Obstetrics and Gynecology (ACOG) subsequently issued guidelines in its 1999 Practice Bulletin which recommended that "VBAC should be attempted in institutions equipped to respond to emergencies with physicians immediately available to provide emergency care." (ACOG, 1999) This practice bulletin also recommended that a physician "capable of monitoring labor and performing an emergency cesarean delivery" be "immediately available throughout active labor," and that anesthesia and personnel for an emergency cesarean be "available."

Logistical and professional liability issues led many hospitals to restrict or prohibit the practice of VBAC. As a result, the rate at which VBAC was attempted fell from 26% in the early 1990s to less than 10% today.

Figure 1. Rates of Total Cesarean Deliveries, Primary Cesarean Deliveries, and Vaginal Birth After Cesarean (VBAC), 1989 to 2007. Data from the National Center for Health Statistics.

Figure 2. Increasing Rates of Cesarean Section, 1991 to 2007. Data from the US Department of Health and Human Services.

Figure 3. Cesarean delivery rates by age of mother. United States, 1998, 2000 & 2007. Data from the US Department of Health and Human Services.

In March 2010, the National Institutes of Health (NIH) hosted its Consensus Development Conference on the subject of VBAC and concluded, "Given the available evidence, trial of labor is a reasonable option for many pregnant women with one prior low transverse uterine incision.".

Also in March 2010, the U.S. Department of Health and Human Services (HHS), Agency for Healthcare Research and Quality (AHRQ) reported that VBAC is a reasonable and safe choice for the majority of women with a history of prior C/S and that there is emerging evidence of serious harm relating to multiple Cesarean Sections.

In July 2010, The American Congress of Obstetricians and Gynecologists (ACOG) similarly revised their own guidelines to be less restrictive of VBAC, stating, "Attempting a vaginal birth after cesarean (VBAC) is a safe and appropriate choice for most women who have had a prior cesarean delivery, including for some women who have had two previous cesareans."

1. Avoiding another scar on your uterus.
   • The more scars you have on your uterus, the greater the chance of problems with a later pregnancy.
2. Decreased Blood Loss
3. Decreased Risk of Blood Transfusion
   • 900 vs. 1,200 per 100,000
   • Factors that increase this risk include induction of labor with no prior vaginal delivery, high-risk pregnancy, and an increased number of prior cesarean deliveries.
4. Decreased Hospital Stay
5. Decreased Medical Costs
6. Decreased Level of Postoperative Pain
7. Decreased Risk of Cesarean Hysterectomy
8. Decreased Risk of Deep Venous Thrombosis
   • 40 vs. 100 per 100,000
9. Decreased Risk of Infection
10. Decreased Risk of Maternal Death
    • overall estimates at all gestational ages of maternal death number 3.8 (TOLAC)vs. 13.4 (ERCS) per 100,000 live births
    • at term, 1.9 (TOLAC) vs 9.6 (ERCS) per 100,000 live births.
    • lower mortality for TOLAC in high-volume hospitals (more than 500 deliveries per year).
11. Decreased Risk of NICU admission for the baby
    • Decreased risk of respiratory distress or sequela
12. Decreased Risk of placenta previa
    • The incidence of placenta previa (placenta covering the cervix) significantly increases in women with each additional C/S delivery
13. Decreased Risks of placenta acreta, placenta increta and placenta percerta
    • placenta accreta reportedly affecting 50-67% of women with placenta previa having three or more C/S.

1. Increased Risk of Uterine Rupture
   • 0.47% chance among women having a TOLAC versus 0.03% among women having a ERCS
   • 6% risk of fetal death if uterus ruptures
2. If VBAC is unsuccessful (failed TOLAC), increased risks of complications as compared to ERCS
   • Risk of Infection doubles if TOLAC fails and C/S is repeated

1. Baby is in the Vertex (Head Down) Position
   • Breech Presentation is Contraindicated
   • Malposition increases risk of failure
2. Baby Weight less than 4500 grams
3. High Bishop Score
   • Favorable cervix
   • Increased success if cervix 75-90% effaced
4. Hospital
   • Increased success in Public vs. Private Hospital
5. Maternal Body Mass Index (BMI) less than 30 kg/m2
6. Maternal Height (Above average)
7. Maternal Education
   • Increased success with greater than 12 years of education
8. No underlining Maternal Medical conditions that make the patient High-Risk
   • Advanced Maternal Age (AMA)
   • Diabetes
   • Hypertension, Preeclampsia, Eclampsia
9. Only 1 previous C/S and no more than 2 previous C/S
   • Risk of Uterine Rupture is 0.2%-0.9% with 1 Previous C/S
   • Risk of Uterine Rupture is 2% with 2 Previous C/S
   • Risk of Uterine Rupture is 3% with 3 Previous C/S
   • Risk of Uterine Rupture is 10-12% with >3 Previous C/S
10. Pregnancy carrying only (1) Baby
    • Twins increase risk of failure
    • Triplets and Increasing Multiples further increase risk of failure and is not recommended
11. Previous Lower Segment Transverse C/S (LSTCS)
    • Risk of Uterine Rupture is 10-11.5% with a Classical C/S
      • 0.64% with scheduled ERCS
      • 11.5% with unplanned TOLAC
    • Increased Risk of Uterine Rupture with Low Vertical Incision (1.1%), T-shaped, Inverted T-shaped, or J-shaped incision.
12. Previous Successful VBAC
    • 60-74% probability with no previous VBAC
    • 90% probability of success with a previous VBAC
    • 0.1-0.5% Risk of Uterine Rupture
13. Race
    • Increased success with Non-Hispanic White
    • Decreased success with Hispanic and Black Race
14. Spontaneous Labor less than 40 weeks of Gestational Age
    • Increased Risk of failure with spontaneous labor or induction of labor greater than 40 weeks of gestational age
15. Spontaneous Labor compared to Induction of Labor
    • 60-74% success rate with spontaneous labor
    • 63% success rate with induction of labor
    • 54% with Transcervical Balloon
    • 2% Risk of Uterine Rupture with Oxytocin Induction
    • 5-15% Risk of Uterine Rupture with Cytotec/Misoprostol Induction
16. The chances of a successful VBAC increases when the medical situation that lead to the previous C/S or failed TOLAC is not repeated in the current TOLAC.

• ERCS, (all gestational ages) not in labor (1:3900)
  • at term, 37 weeks+ (1:4400)
• ERCS or TOLAC (all gestational ages) in labor (1:300 to 1:100)
  • at term, 37 weeks+ (1:125)
• TOLAC, augmentation of labor using oxytocin (1:250 to 1:100)
• TOLAC, induction of labor using oxytocin (1:65 to 1:50)
  • at term, 37-40 weeks (1:65)
  • greater than 40 weeks (1:30)
  • Using Prostaglandins (1:20)
• Previous Vaginal Delivery and/or Successful TOLAC/VBAC (1:200)
  • Induction with oxytocin (1:100 to 1:50)
• Unscarred uterus in labor (1:30,000 to 1:10,000)

There is an association between C/S delivery and abnormal placental position and growth in subsequent pregnancies. This risk begins following the first C/S and increases with each subsequent C/S, especially after 4 C/S. Therefore, it is important to consider this risk in women wanting to have large families.

The incidence of placenta previa (placenta covering the cervix) significantly increases in women with each additional C/S delivery:

• One C/S: 0.9%
• Two C/S: 1.7%
• Three: 3.0%
• Four: 10%

The presence of placenta previa is also associated with an increased incidence of placenta accreta, increta, and percreta.

Under normal circumstances, the placenta attaches to the uterine wall in the upper portion of the uterus (fundus) and it does so like a suction cup without deeply penetrating into the uterine tissue or muscle. Placenta Accreta, Increta and Percreta are all abnormal and potentially life threatening attachments of the placenta into muscle and sometimes through the entire uterine wall to include adjacent organs such as the bladder and rectum.

Placenta accreta is an invasion of the myometrium which does not penetrate the entire thickness of the uterine muscle. It is the most common form of the condition and accounts for 75-78% of cases.

Placenta increta occurs when the placenta further extends into the myometrium, penetrating deeper into the muscle. This represents 17% of cases.

Placenta percreta represents the worst of this condition, when the placenta penetrates the entire myometrium through the entire uterine wall. This variant can lead to the placenta attaching to other organs such as the rectum or bladder. This represents 5-7% of cases.

Infants born by ERCS are at increased risk for birth trauma such as fetal lacerations caused by the surgical knife used to make the C/S incision.

However, brachial plexus injuries are more common with VBAC as compared to ERCS. The brachial plexus is a network of nerves originating in the spinal cord, and innervating to the shoulder, arm and hand. Brachial plexus injuries are caused by damage to those nerves.

Injury to this area it most commonly associated with shoulder dystocia, an impaction of the infant's shoulder behind the maternal symphysis pubis (pubic bone). The lateral traction on the head, as part of the corrective maneuvers to deliver the infant during a shoulder dystocia, stretches the brachial plexus, leading to injury 4%-40% of the time.

Studies of brachial plexus injury show an overall risk of between 1:2500 to 1:250 live births. An incidence of brachial plexus injury in infants born by VBAC is 1.8:1,000 compared to 3:10,000 among infants born by ERCS.

Therefore, the risk of brachial plexus injuries during VBAC is no greater than that of normal vaginal deliveries, but greater than in ERCS.

A commonly stated reason to perform either an elective Cesarean Section or Elective Repeat Cesarean (ERCS) is to avoid potential fetal brain injury or birth trauma from a delivery through the birth canal.

One of the most severe forms of brain injury, called Celebral Palsy (CP), was at one time thought to be most commonly associated with a vaginal delivery; however, a review of the most recent medical data demonstrates that the causes of CP are multi-factorial with fewer than 10% specifically associated with birth trauma.

Definition of Celebral Palsy (CP):

Celebral Palsy is an broad term which includes a group of permanent, non-progressive, non-contagious motor conditions that cause physical disability in human brain function, most commonly seen by defects in body movement and control. Cerebral refers to the cerebrum, which is the affected area of the brain (although the disorder most likely involves problems with the connection between the cortex and other parts of the brain such as the cerebellum), and Palsy which refers to a disorder of movement.

CP occurs in approximately 1/500 live births. There is no known cure for this condition and medical management is limited to the prevention and treatment of complications arising from the effects of CP.

Causes of Celebral Palsy:

CP is caused by damage to the motor control centers of the developing brain and can occur during pregnancy, during childbirth or after birth up to about age three. These effects cause problems in movement and posture cause activity and are often accompanied by disturbances of cognitive reasoning, speech and communication, sensation, depth perception, and other sight-based perceptual problems.

Approximately one third of children also suffer from epilepsy.

Possible causes of CP during pregnancy:

• Infections such as Toxoplasmosis, Rubella, Cytomegallovirus (CMV), Herpes Simplex and Group B Strep
• Genetic Defects
• Exposure to Radiation
• Maternal Malnutrition
• Maternal use of prescription drugs and illegal drug use
• Multiple Births
• Placental abnormalities to include placental insufficiency and associated Intrauterine Growth Restriction (IUGR) and placental abruption
• Premature Birth (40-50% of all CP cases)
• Sustained umbilical cord compression or blood flow occlusion leading to significant oxygen reduction to the brain of the baby, either hypoxia or asphyxia (Less than 10% of all cases)
• Uncontrolled Maternal Chronic Hypertension, Pre-eclampsia and Eclampsia
• Uncontrolled Diabetes, Thyroid disease to include Hypothyroidism and Hyperthyroidism

Possible causes of CP during labor:

• Sustained umbilical cord compression or blood flow occlusion leading to significant oxygen reduction to the brain of the baby, either hypoxia or asphyxia (Less than 10% of all cases)
• Placenta Abruption
• Placenta Previa
• Shoulder Dystocia with associated Brachial Plexus injury

Possible causes of CP following labor:

• Infections, such as encephalitis and meningitis
• Ingestion of toxins, such as lead poisoning
• Near asphyxiation, such as choking on foreign objects (toys and pieces of food) or near drowning
• Physical brain injury, such as shaken baby syndrome
• Severe jaundice
• Untreated seizures and epilepsy

Based on the current data, neither an elective Cesarean Section nor an ERCS is recommended to specifically reduce the risk of CP. Further, there is no consensus of data that the risk of CP is increased by attempting a VBAC or that ERCS is significantly safer than VBAC in reducing the risk of CP.

There is a limited amount of evidence to suggest that becoming pregnant shortly after having a C/S increases the risk of uterine rupture in the subsequent pregnancy. There are generally three intervals of time with decreasing risk of uterine rupture associated with each group.

An interval of pregnancy of less than 6 months since the previous C/S delivery appears to be associated with the highest risk of uterine rupture.

An interval of between 6 months to 2 years appears to have the next lowest risk of uterine rupture.

And an interval of greater than 2 years appears to have the lowest risk of uterine rupture.

Stamilio (2007), in a study involving 286 women who got pregnant within 6 month of their C/S had a uterine rupture rate of 3.05% as compared to 0.9% (3x higher). Stamiliio stated,

"We hypothesized that short interpregnancy intervals may lead to altered wound healing and an increased risk of uterine rupture in patients who attempt a vaginal birth after cesarean. Our hypothesis is based on previous observational studies that suggest an association between short birth interval and increased adverse perinatal outcomes and wound-healing research that indicates that uterine smooth muscle tissue repair evolves over several months... Importantly, there is radiographic and hysteroscopic evidence that cesarean scar development is incomplete as long as 6 or 12 months postoperatively."

Bujold E, Gauthier RJ (2010), in a studiy of 1768 women, found a uterine rupture rate of 1.3% for interdelivery period of 24 months or longer, 1.9% for interdelivery periods between 18-23 months and 4.8% for interdelivery period of less than 18 months.

Based on this limited data, it is recommended that a patient wait 2 years between a previous C/S and the next pregnancy in order to keep the risk of uterine rupture below 1%. If a patient were to become pregnant less than 6 months, with her last delivery being by C/S, she should be counseled that her risks of uterine rupture are between 1-5% and a ERCS over VBAC should be considered. However, there are no specific contraindications to attempting a VBAC.

The following recommendations are based on Dr. Novoa's 30 years of experience having assisted in over 500 VBACs (Including Previous C/S x 2,3,4) with a VBAC Success Rate at an estimated 90% with no maternal or fetal morbidity or mortality.

1. Pick the right doctor. While thousands of doctors claim to support VBAC, it requires not only a doctor that supports VBAC but one with experience and a high success rate.

   When possible, ask your doctor what is their VBAC Success Rate. The national average is approximately 70%.

2. Avoid elective inductions, even at 39 weeks and beyond.

   Elective inductions have a relatively high failure rate. Elective VBAC inductions can significantly increase your risk of failure or scare your doctor into a premature stoppage of a TOLAC leading to unnecessary Cesarean Section.

   Spontaneous Labor with unassisted progress and Spontaneous rupture of membranes is safer than induction by any method to include AROM, Foley bulb or Pitocin.  Misoprostol is contraindicated.

3. What is the Lower Uterine Segment Thickness (LUST).

   The LUST may be the single most important factor in avoiding a Uterine Rupture.

   The thicker, the better. A thickness of 3mm or greater is optimal.  A thickness less then than 2mm is suboptimal or generally not recommended to attempt a TOLAC due to higher risk of uterine rupture.

   The thickness should be measured by ultrasound a few days before labor or during early labor.

4. Location and type of previous Cesarean section.

   A HORIZONTAL lower uterine segment is optimal.

   A lower VERTICAL incision is acceptable. A HIGH VERTICAL, "CLASSICAL", Previous Uterine surgeries penetrating through the myometrium is subtotal and generally not recommended.

5. Epidural and IUPC

   An Epidural catheter should be placed upon admission. Medication can be gauged by how much the patient wants to feel. It is also prevents any delay with anesthesia in case of a STAT Cesarean section.

   An Intrauterine Pressure Catheter or IUPC can be beneficial in determining the intensity of natural vs artificially induced contractions calculated by Montevideo units. While an IUPC may not predict or confirm an Uterine Rupture,  it can objectively document a change in the contraction pattern or show early intrauterine bleeding with backflow into the catheter.