My goal for this post is to be a single repository of good VBAC information for myself and others. In this entry I intend to make a reasoned case for why pursuing VBAC is important and why providers should support it, as well as collecting good resources and research to this end.
The American College of Obstetrics and Gynecology (ACOG) recommends that women with a single low-transverse uterine scar are good candidates for a VBAC "trial of labor" (VBAC-TOL), and should be offered one at any institution which can safely support it.[1]
Criteria for selecting candidates for VBAC include the following: (1) one previous low-transverse cesarean delivery; (2) clinically adequate pelvis; (3) no other uterine scars or previous rupture; (4) a physician immediately available throughout active labor who is capable of monitoring labor and performing an emergency cesarean delivery; and (5) the availability of anesthesia and personnel for emergency cesarean delivery.
Points 4 and 5 are often cited as grounds to refuse a VBAC-TOL. Personally, I would not feel safe delivering at any institution which is not capable of performing an emergency cesarean. True emergency cesareans are rare, but can occur with any birth. In fact, the incidence of uterine rupture during VBAC is lower than other complications which necessitate emergency cesarean. Placenta Abruption occurs in approximately 1% of pregnancies and is truly an emergency situation. Other complications that can necessitate emergency c-section include prolapsed cord and fetal distress.
[2] While the odds of a VBAC mother needing an emergency cesarean are slightly higher than standard vaginal birth because the risk of uterine rupture is added to the usual risks, the odds of uterine rupture creating the need for an emergency cesarean are less than 1%. In short, VBAC deliveries aren't any more likely to require emergency cesarean than any other birth.
[3][19]
"The probability of requiring an emergency cesarean section for acute other conditions (fetal distress, cord prolapse, or antepartum hemorrhage) in any woman giving birth, is approximately 2.7%, or up to 30 times as high as the risk of uterine rupture with a planned vaginal birth after cesarean... Hospitals whose capabilities are so limited that they cannot deal promptly with problems associated with a planned vaginal birth after cesarean are also incapable of dealing with other obstetrical emergencies."[14]
From
A Guide to Effective Care in Pregnancy and Childbirth, via
Childbirthconnection.orgThe World Health Organization (WHO) has stated that in developed countries, the cesarean rate should be no higher than 10-15%. But the most recent numbers in the U.S. show a rate of 31.8%.
[13] There is a lot of work to be done in lowering initial cesarean sections, and that is the best way to reduce the overall cesarean rate, as a significant portion of cesareans are repeat. When an average of 75-80% of VBAC-TOL attempts are successful, but the overall VBAC rate is low, large numbers of cesareans are performed solely for the reason of prior cesarean delivery, but could likely be a successful vaginal birth instead.
[14]Overall, vaginal birth, even after cesarean is safer, and has better outcomes for mom, baby, and future children as compared to cesarean delivery.
[7][25][26]ACOG's guidelines state that a risk model for VBAC states that "it is reasonable to consider a trial of labor if the chance of success is 50% or greater."
[34] Statistically, all groups of VBAC-TOL in research show a greater than 50% success rate.
[26]
Cesarean Risks
Critically important to the argument in favor of VBAC are the risks associated with cesarean delivery, and repeat cesarean delivery. There is also increasing information about negative effects of cesarean delivery that are not always included in discussions of cesarean risks, but continue to affect cesarean mothers and children.
Risks for the mother include:· Increased recovery time (pain, difficulty in movement)
· Maternal Death (2-4x that of vaginal birth, 1 in 50,000)
· Clotting
· Hemorrhage/transfusion
· Infection (30%)
· Surgical injury
· Hysterectomy
· Adhesions (bowel obstruction, increased risk in future surgeries)
· Fertility problems (Infertility, miscarriage, ectopic pregnancy)
· Postpartum depression/emotional effects
· Increased recovery time
· Prolonged hospital stay, re-hospitalization, admittance to ICU
· Anesthetic complications
· Cardiac arrest
Risks for the baby include:· Neonatal death
· Respiratory issues, including asphyxia
· Persistent pulmonary hypertension
· Surgical trauma (accidental cuts) (2-6%)
· Prematurity
· Increased NICU admission
· Delay or difficulty in breastfeeding initiation
· Asthma
[29]· Delayed neurological development
Increased risks for future pregnancies:· Uterine rupture
· Placental issues (previa, accreta, abruption)
· Malpresentation
· Preterm birth
· Low birth weight
· Stillbirth
· Ectopic pregnancy
· Malformation
· Neonatal death
· Neurological injury
References for this section: [3][6][7][8][9][12][14][29][31][32][33][36]Overall morbidity associated with vaginal birth is 1/5th of elective cesarean failed labor that results in a cesarean delivery have twice the morbidity of elective c-section. Maternal mortality rates are 4 times higher with cesarean section, 2 times higher with elective repeat cesarean as compared to all vaginal births.
[14] Planned cesareans are associated with lower risks than those performed after labor has commenced, or for urgent/emergent needs, but are still associated with a 3 times higher rate of maternal morbidity.
[33]
VBAC vs. Repeat Cesearean
The primary additional risk in a VBAC birth is uterine rupture, and possible consequences from rupture. While the risk of uterine rupture is greatly increased in a scarred uterus over an non-scarred one, the actual risk of uterine rupture during VBAC-TOL varies by study, but is around 0.2-0.6%. However, the existence of a prior cesarean scar is a risk factor for uterine rupture, (0.16-0.28%)
[3] and rupture can occur in any delivery.
[4] The most catastrophic ruptures tend to occur in the non-scarred uterus.
[20] There is no significant statistical increase in fetal death from VBAC over repeat cesarean.
[3]The risk of rupture is also greatly increased by labor augmentation.
[5] However, even when rupture occurs, most are not catastrophic, and do not lead to significant complications. Damage to the baby as a result of rupture is extremely rare: .46 per 1000 VBAC-TOL attempts, or 0.05%.
[3][11] In the event that a uterine rupture occurs, immediate cesarean delivery reduces the risks of complications for mother and baby.
Every VBAC delivery also inherits risks associated with vaginal birth:· Tears in the perineum and vagina
· Hemorrhage and transfusions*
· Readmission to hospital*
· Infection*
· Pain in the vaginal area
· Bowel problems, bowel incontinence*
· Hemorrhoids
· Birth injury to baby
*Overall the the risk of these complications is less than associated with cesarean delivery.Risks specific to VBAC:· Uterine rupture (blood loss, fetal morbidity, hysterectomy, infection)
· Endometritis
Repeat cesarean section carries with it all the risks of cesarean section, but each additional incision greatly increases specific risks:· Placenta issues: previa, accreta (2C: .13%, 4C: 2.13%, 6+C: 6.74%) abruption
[37]· Uterine rupture
· Secondary infertility: miscarriage, ectopic pregnancy
· Emergency hysterectomy (2C: 0.42%, 4C: 2.4%, 6+C: 8.99%)
[37]· Scar tissue issues: adhesions, increased difficulty & injury in subsequent cesareans
[23]· Cardiovascular complications: heart attack, stroke, death
· Netonatal mortality
· Higher risk of surgical injury
Women who successfully deliver VBAC have half the morbidity of elective repeat cesarean. Perinatal mortality rates for VBAC are 3 per 1000.
[14] Benefits of VBAC:
· Faster recovery
· Better breastfeeding initiation and bonding with baby
· Fewer risks in current pregnancy/delivery
· Fewer risks for subsequent pregnancies
· Fewer respiratory issues in the baby
· Fewer long-term respiratory and neurological effects
· Better maternal psychological/emotional outcomes, less post-partum depression
· Fewer infections, clots, and less blood loss.
References for this section: [3][9][10][12][14][29][35][36][37][38]Honesty about factors affecting VBAC
Positive indicators for VBAC:· Non-repeating indication for prior cesarean breech presentation.
· Prior vaginal birth (particularly prior VBAC)
· Low transverse uterine incisions
· 18-24+ months between deliveries
· Maternal age of less than 30 years
· Spontaneous start of labor
Legitimate contraindications:· "Classic" or high vertical uterine incision, inverted-T incision.
· Standard medical indications for cesarean (placenta previa, fetal distress, shoulder dystocia, etc.)
· Combination of factors that comprise an overall high risk for rupture and complication that outweighs cesarean risks.
· Prior uterine rupture
· Abnormal uterine shape
Factors that decrease VBAC success, or increase rupture risk:Note that these are not the same as contraindications, but factors that change the success rates and risks of complications. These should be weighed in the decision as to whether or not an individual is a candidate for VBAC, and finds the risks acceptable.
Where I could find specific data: (success rates){rupture risk factor}
· Labor induction
(67%) {2-5x}
[3][21] especially using multiple agents. Augmentation (73.9%)[
14]
· Manual inspection post-birth for dehiscence. This can introduce infection, or worsen small tears, if the exist.
· Prior cesarean sutured with single-layer, not double layer.[30]· Inter-pregnancy interval of less than 18 months. {2-3%}[21][22]· Advanced Maternal Age[22]· Maternal obesity (56-68%)[18]
· Multiple prior cesareans {3-5x}[21][27][34]· Prior cesarean for failure to progress (63%)[17]
· Baby larger than 4000g, especially larger than 4250g [8lbs 13oz, 9lbs 6oz] (62%)[24]
· Admittance to hospital during early labor (66.8%)
· Postdates pregnancy (64.8%)
· Breech presentation
· Infection following the prior cesarean
· Ultrasound findings indicating a thin uterine scar
References for this section: [14][15][16][17][21][26][27][28][29][34]Myths:· Macrosomia, shoulder dystocia, cephalo-pelvic disproportion, and failure to progress as reasons for prior cesarean cannot VBAC: While these factors stastically reduce VBAC success, they are not associated with increases in uterine rupture, and 50-75% of VBAC-TOLs are successful.
[14][16][27]· Low vertical incisions have too high a risk of uterine rupture: Data is more limited for this incision type, but the existing data shows no signficant difference between low-transverse and low-vertical incisions. The greatest uterine risk comes from incisions that cross the fundus, or upper part of the uterus.
[15][20]· Epidural or narcotic anesthesia can mask symptoms of uterine rupture: There are extremely few recorded cases of this happening. Pain is not a reliable indicator of rupture, but can be predicted and detected by signs of fetal distress, and pain from rupture can be felt through the epidural block. Epidural use can decrease fetal heartrate, and lead to false suspicion of rupture.
[3][30]· Multiple prior cesareans are too risky: While the risk of uterine rupture increases with each additional cesarean, in VBAC2C the risk of rupture is 1-3.7%. Less data exists for 3 or more cesareans, but they can deliver vaginally safely, especially with a prior vaginal birth.
[34]· Maternal Genital Herpes must be delivered via c-section: Current ACOG guidelines indicate cesarean delivery for maternal genital herpes only if a lesion is present.
[28]· Twins must be delivered via c-section: There is no evidence that a twin delivery increases risk of uterine rupture, but there is little data.
[26]· Low rating from a scoring system: Half of mothers scoring low on rating systems successfulyl VBAC.
[26]The Bottom Line
The bottom line is that cesarean deliveries carry myriad risks to mother, baby, and future pregnancies, and should be avoided where possible. VBAC is an overall safe method of delivery that carries fewer risks than repeat cesarean delivery, and should be pursued when the mother is a candidate in order the achieve better outcomes and reduce the number cesarean deliveries, and the complications they cause.
VBAC Resources
·
I-CAN Online·
VBACFacts.com·
The Unnecesarean·
Childbirth Connection &
Resource List·
A Guide to Effective Care in Pregnancy and Childbirth·
Journal of Family Practice·
ACOG &
VBAC Practice Bulletin, 2004·
Vbac.com·
Childbirth.org·
About.com·
Midwifery Today·
AmericanPregnancy.org·
TheBusinessofBeingBorn.com·
Lamaze InternationalComplete list of References
1. http://www.aafp.org/afp/20041001/practice.html
2. http://pregnancychildbirth.suite101.com/article.cfm/emergency_cesareans_
3. http://vbacfacts.com/vbac/
4. http://www.collegeofmidwives.org/news01/CS%20URupt%20Cal%201995%20feb03.htm
5. http://content.nejm.org/cgi/content/full/345/1/3
6. http://vbacfacts.com/2008/06/05/cesarean-risks-overview/
7. http://vbacfacts.com/2009/03/08/study-finds-vbac-as-safe-as-repeat-cesarean/
8. http://ican-online.org/vbac/postion-statement-elective-cesareans-riskier-than-vaginal-birth
9. http://www.ican-online.org/pregnancy/cesarean-fact-sheet
10. http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6W9P-45SR5S6-CX&_user=10&_coverDate=11/30/2000&_rdoc=1&_fmt=&_orig=search&_sort=d&view=c&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=548df3999fa1afadfbe9e8fb2610d921
11. http://content.nejm.org/cgi/content/short/351/25/2581
12. http://en.wikipedia.org/wiki/Caesarean_section
13. http://www.cdc.gov/nchs/data/nvsr/nvsr57/nvsr57_12.pdf
14. http://www.childbirthconnection.org/pdfs/gecpc3ch38.pdf
15. http://vbac.com/uterine.html
16. http://www.childbirth.org/section/CSFact.html
17. http://vbacfacts.com/2008/04/14/two-doctors-respond-to-the-hastings-indian-medical-center-vbac-ban-and-encourage-native-american-women-to-vbac/
18. http://www.ajog.org/article/S0002-9378%2804%2900535-6/abstract
19. http://vbacfacts.com/2009/10/19/response-to-ob-scare-tactics-vs-informed-consent-aka-why-i-started-this-website/
20. http://www.childbirth.org/section/resVBAC.html
21. http://www.jfponline.com/Pages.asp?AID=3307
22. http://forums.obgyn.net/ob-gyn-l/OBGYNL.0206/0008.html
23. http://www.pregnancy-info.net/c-section_adhesions.html
24. http://www.ajog.org/article/S0002-9378%2801%2902142-1/abstract
25. http://www.ajog.org/article/S0002-9378%2806%2900769-1/abstract
26. http://www.childbirthconnection.org/article.asp?ck=10211
27. http://www.birthrites.org/guidelines.html
28. http://www.americanpregnancy.org/labornbirth/vbac.html
29. http://www.childbirthconnection.org/article.asp?ck=10210
30. http://www.childbirthconnection.org/article.asp?ck=10214
31. http://www.ncbi.nlm.nih.gov/pubmed/16846577?dopt=Abstract
32. http://www.ncbi.nlm.nih.gov/pubmed/17261119
33. http://www.cmaj.ca/cgi/content/full/176/4/475
34. http://www.acog.org/acog_districts/dist9/pb054.pdf
35. http://www.obgyn.net/women/articles/VBAC_dah.htm
36. http://www.childbirthconnection.org/pdfs/cesareanbookletinsert.pdf
37. http://vbacfacts.com/2009/08/03/maternal-morbidity-associated-with-multiple-repeat-cesarean-deliveries/
38. http://www.medscape.com/viewarticle/573948