Delivery after previous caesarean section

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Vaginal birth after caesarean
MeSH D016064

In case of a previous caesarean section a subsequent pregnancy can be planned beforehand to be delivered by either of the following two main methods:

Contents

Both have higher risks than a vaginal birth with no previous caesarean section. There are many issues which affect the decision for planned vaginal or planned abdominal delivery. There is a slightly higher risk for uterine rupture and perinatal death of the child with VBAC than ERCS, but the absolute increased risk of these complications is small, especially with only one previous low transverse caesarean section. [1] A large majority of women planning VBAC will achieve a successful vaginal delivery, although there are more risks to the mother and baby from an unplanned caesarean section than from an ERCS. [2] [3] Successful VBAC also reduces the risk of complications in future pregnancies more than ERCS. [4]

In 2010, the National Institutes of Health, U.S. Department of Health and Human Services, and American Congress of Obstetrics and Gynecology all released statements in support of increasing VBAC access and rates. [5] [6] [7] [8] Recently, it is recognized that as the number of cesarean sections a patient undergoes increases so does the risk of significant obstetrical complications [9] It is still suggested to try VBAC over ERCS even with its slightly higher risk of uterine rupture. Both VBAC and ERCS have risks, it is always better to decide delivery based on birthing person's body condition and preferred birthing experience, and advice from health professionals.


Technique

Where the woman is labouring with a previous section scar (i.e. a planned VBAC in labour), depending on the provider, special precautions may be recommended. These include intravenous access (a cannula into the vein) and continuous fetal monitoring (cardiotocography or CTG monitoring of the fetal heart rate with transducers on the mother's abdomen). Most women in the UK should be counselled to avoid induction of labour if there are no medical reasons for it, as the risks of uterine rupture of the previous scar are increased if the labour is induced. Other intrapartum management options, including analgesia/anesthesia, are identical to those of any labour and vaginal delivery. [10]

For ERCS, the choice of skin incision should be determined by what seems to be most beneficial for the present operation, regardless of the choice of the previous location as seen by its scar, although the vast majority of surgeons will incise through the previous scar to optimise the cosmetic result. Hypertrophic (very thick or unsightly) scars are best excised because it gives a better cosmetic result and is associated with improved wound healing. On the other hand, keloid scars should have their margins left without any incision because of risk of tissue reaction in the subsequent scar. [11]

Selection criteria

The choice of VBAC or ERCS depends on many issues: medical and obstetric indications, maternal choice and availability of provider and birth setting (hospital, birthing center, or home). Some commonly employed criteria include: [3]

Factors favoring VBAC

Factors favoring ERCS

According to ACOG guidelines, the following criteria may reduce the likelihood of VBAC success but should NOT preclude a trial of labour: having two prior caesarean sections, suspected fetal macrosomia at term (fetus greater than 4000-4500 grams in weight), gestation beyond 40 weeks, twin gestation, and previous low vertical or unknown previous incision type, provided a classical uterine incision is not suspected. [13]

Criteria where ERCS should be performed

The presence of any of the following practically always mean that ERCS will be performed – but this decision should always be discussed with a senior obstetrician: [14]

Outcomes in VBAC versus ERCS

VBAC and ERCS differ in outcomes on many end-points.

The American Congress of Obstetricians and Gynecologists (ACOG) states that VBAC is associated with decreased maternal morbidity and a decreased risk of complications in future pregnancies than ERCS. [4]

Uterine rupture

A caesarean section leaves a scar in the wall of the uterus which is considered weaker than the normal uterine wall. A VBAC carries a risk of uterine rupture of 22–74/10,000. Slightly lower risk of uterine rupture in women undergoing ERCS (i.e. a section before the onset of labour). [1] Mothers with a previous lower uterine segment cesarean are considered the best candidates for VBAC, as that region of the uterus is under less physical stress during labor and delivery. Although there is higher risk of uterine rupture in VBAC than ERCS, both rates happen to be very low. Sometimes no significant difference in uterine rupture rates is found between the groups of VBAC and ERCS. [15] If a uterine rupture does occur, the risk of perinatal death is approximately 6%. [16] Even it happens, most birthing parents and babies will recover completely after uterine rupture. [17]

Risks to the child

A VBAC carries a 2–3/10,000 additional risk of birth-related perinatal death when compared with ERCS. [1] The absolute risk of such birth-related perinatal loss is comparable to the risk for women having their first birth. [1] Planned VBAC carries an 8/10,000 risk of the child developing hypoxic ischaemic encephalopathy, but the long-term outcome of the infant with HIE is unknown and related to many factors. [1]

On the other hand, attempting VBAC reduces the risk that the child will have respiratory problems after birth such as infant respiratory distress syndrome (IRDS), as rates are estimated at 2–3% with planned VBAC and 3–4% with ERCS. [1]

Conversion from planned VBAC to Caesarean

Of the women who have previously had a Caesarean, only about 8% of them will opt for a VBAC. However, of the 8% that opt for a VBAC, between 75%-80% will successfully give birth vaginally, which is comparable to the overall vaginal delivery rate in the United States in 2010. [2] [3] [18]

The chance of having a successful VBAC is decreased by the following factors: [1]

When the first four factors are present, successful VBAC is achieved in only 40% of cases. In contrast, in women with a previous caesarean section who have had a subsequent vaginal birth, the chance of a successful vaginal birth again is estimated at 87–90%. [1]

Risks in future pregnancies

ERCS, as compared to VBAC, further increases the risks of complications in future pregnancies. Complications whose risks significantly increase with increasing number of repeated caesarean sections include: [1]

Other

Aside from uterine rupture risk, the drawbacks of VBAC are usually minor and identical to those of any vaginal delivery, including the risk of perineal tearing. Maternal morbidity, NICU admissions, length of hospital stay, and medical costs are typically reduced following a VBAC rather than a repeat caesarean delivery.[ citation needed ]

A VBAC, compared with ERCS, carries around 1% additional risk of either blood transfusion (mainly because of antepartum hemorrhage), postpartum haemorrhage or endometritis. [1]

Society and culture

While vaginal births after caesarean (VBAC) are not uncommon today, the rate of VBAC has declined to include less than 10% of births after previous caesarean in the USA. [19] [20] Although caesarean deliveries made up only 5% of births overall in the USA until the mid-1970s, it was commonly believed that for women with previous caesarean sections, "Once a Caesarean, always a Caesarean". A consumer-driven movement supporting VBAC changed medical practice and led to soaring rates of VBAC in the 1980s and early 1990s, but rates of VBAC dramatically dropped after the publication of a highly publicized scientific study showing worse outcomes for VBACs as compared to repeat caesarean and the resulting medicolegal changes within obstetrics. [21] In 2010, the National Institutes of Health, U.S. Department of Health and Human Services, and American Congress of Obstetrics and Gynecology all released statements in support of increasing VBAC access and rates. [5] [22] [23] [8]

Although caesarean sections made up only 5% of all deliveries in the early 1970s, [24] among women who did have primary caesarean sections, the century-old opinion held, "Once a caesarean, always a caesarean." Overall, cesarean sections became so commonplace that the caesarean delivery rate climbed to over 31% in 2006. [4] A mother-driven movement supporting VBAC changed standard medical practice, and rates of VBAC rose in the 1980s and early 1990s. However, a major turning point occurred in 1996 when one well publicized study in The New England Journal of Medicine reported that vaginal delivery after previous caesarean section resulted in more maternal complications than a repeat caesarean delivery. [25] The American Congress of Obstetrics and Gynecology subsequently issued guidelines which identified VBAC as a high-risk delivery requiring the availability of an anesthesiologist, an obstetrician, and an operating room on standby. [26] Logistical and legal (professional liability) concerns led many hospitals to enact overt or de facto VBAC bans. As a result, the rate at which VBAC was attempted fell from 26% in the early 1990s to 8.5% in 2006. [4] [27]

In March 2010, the National Institutes of Health met to consolidate and discuss the overall up-to-date body of VBAC scientific data and concluded, "Given the available evidence, trial of labor is a reasonable option for many pregnant women with one prior low transverse uterine incision." [5] Simultaneously, the U.S. Department of Health and Human Services Agency for Healthcare Research and Quality reported that 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. [16] 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." [28] and this is also the current position of the Royal College of Obstetricians and Gynaecologists in the UK.

Enhanced access to VBAC has been recommended based on the most recent scientific data on the safety of VBAC as compared to repeat caesarean section, including the following recommendation emerging from the NIH VBAC conference panel in March 2010, "We recommend that hospitals, maternity care providers, health care and professional liability insurers, consumers, and policymakers collaborate on the development of integrated services that could mitigate or even eliminate current barriers to trial of labor." [5] The U.S Department of Health and Human Services' Healthy People 2020 initiative includes objectives to reduce the primary caesarean rate and to increase the VBAC rate by at least 10% each. [29]

The American Congress of Obstetricians and Gynecologists (ACOG) modified the guidelines on vaginal birth after previous Caesarean delivery in 1999, 2004, and again in 2010. [30] In 2004, this modification to the guideline included the addition of the following recommendation:

Because uterine rupture may be catastrophic, VBAC should be attempted in institutions equipped to respond to emergencies with physicians immediately available to provide emergency care. [12]

In 2010, ACOG modified these guidelines again to express more encouragement of VBAC, but maintained it should still be undertaken at facilities capable of emergency care, though patient autonomy in assuming increased levels of risk should be respected (ACOG Practice Bulletin Number 115, August 2010).

The recommendation for access to emergency care during trial of labor has, in some cases, had a major impact on the availability of VBACs to birthing mothers in the US. For example, a study of the change in frequency of VBAC deliveries in California after the change in guidelines, published in 2006, found the VBAC rate fell to 13.5% after the change, compared with 24% VBAC rate before the change. [31] The new recommendation has been interpreted by many hospitals as indicating a full surgical team must be standing by to perform a Caesarean section for the full duration of a VBAC woman's labor. Hospitals that prohibit VBACs entirely are said to have a 'VBAC ban'. In these situations, birthing mothers are forced to choose between having a repeat Caesarean section, finding an alternate hospital in which to deliver their babies or attempting delivery outside the hospital setting. [32]

Most recently, enhanced access to VBAC has been recommended based on updated scientific data on the safety of VBAC as compared to repeat caesarean section, including the following recommendation emerging from the NIH VBAC conference panel in March 2010, "We recommend that hospitals, maternity care providers, health care and professional liability insurers, consumers, and policymakers collaborate on the development of integrated services that could mitigate or even eliminate current barriers to trial of labor." [5] The U.S Department of Health and Human Services' Healthy People 2020 initiative includes objectives to reduce the primary cesarean rate and to increase the VBAC rate by at least 10% each. [8]

Position statements

ACOG recommends that obstetricians offer most women with one prior cesarean section with a low-transverse incision a trial of labor (TOLAC) and that obstetricians should discuss the risks and benefits of VBAC with these patients. [4]

This VBAC success calculator is a useful educational tool (noted by the US Agency for Healthcare Research and Quality) for clinicians who are discussing the risks and benefits of VBAC with their patients. [33]

VBAC versus no previous Caesarean section

VBAC, compared to vaginal birth without a history of Caesarean section, confers an increased risks for placenta previa, placenta accreta, prolonged labor, antepartum hemorrhage, uterine rupture, preterm birth, low birth weight, and stillbirth. However, some risks may be due to confounding factors related to the indication for the first caesarean, rather than due to the procedure itself. [34]

See also

Related Research Articles

<span class="mw-page-title-main">Caesarean section</span> Surgical procedure in which a baby is delivered through an incision in the mothers abdomen

Caesarean section, also known as C-section or caesarean delivery, is the surgical procedure by which one or more babies are delivered through an incision in the mother's abdomen. It is often performed because vaginal delivery would put the mother or fetus at risk. Reasons for the operation include obstructed labor, twin pregnancy, high blood pressure in the mother, breech birth, shoulder presentation, and problems with the placenta or umbilical cord. A caesarean delivery may be performed based upon the shape of the mother's pelvis or history of a previous C-section. A trial of vaginal birth after C-section may be possible. The World Health Organization recommends that caesarean section be performed only when medically necessary.

<span class="mw-page-title-main">Ectopic pregnancy</span> Female reproductive system health issue

Ectopic pregnancy is a complication of pregnancy in which the embryo attaches outside the uterus. Signs and symptoms classically include abdominal pain and vaginal bleeding, but fewer than 50 percent of affected women have both of these symptoms. The pain may be described as sharp, dull, or crampy. Pain may also spread to the shoulder if bleeding into the abdomen has occurred. Severe bleeding may result in a fast heart rate, fainting, or shock. With very rare exceptions, the fetus is unable to survive.

<span class="mw-page-title-main">Childbirth</span> Expulsion of a fetus from the pregnant mothers uterus

Childbirth, also known as labour, parturition and delivery, is the completion of pregnancy where one or more babies exits the internal environment of the mother via vaginal delivery or caesarean section. In 2019, there were about 140.11 million human births globally. In the developed countries, most deliveries occur in hospitals, while in the developing countries most are home births.

<span class="mw-page-title-main">Misoprostol</span> Medication to induce abortion and treat ulcers

Misoprostol is a synthetic prostaglandin medication used to prevent and treat stomach and duodenal ulcers, induce labor, cause an abortion, and treat postpartum bleeding due to poor contraction of the uterus. It is taken by mouth when used to prevent gastric ulcers in people taking nonsteroidal anti-inflammatory drugs (NSAID). For abortions it is used by itself or in conjunction with mifepristone or methotrexate. By itself, effectiveness for abortion is between 66% and 90%. For labor induction or abortion, it is taken by mouth, dissolved in the mouth, or placed in the vagina. For postpartum bleeding it may also be used rectally.

<span class="mw-page-title-main">Placenta praevia</span> Medical condition

Placenta praevia is when the placenta attaches inside the uterus but in a position near or over the cervical opening. Symptoms include vaginal bleeding in the second half of pregnancy. The bleeding is bright red and tends not to be associated with pain. Complications may include placenta accreta, dangerously low blood pressure, or bleeding after delivery. Complications for the baby may include fetal growth restriction.

<span class="mw-page-title-main">External cephalic version</span> Process by which a breech baby can sometimes be turned from buttocks or foot first to head first

External cephalic version (ECV) is a process by which a breech baby can sometimes be turned from buttocks or foot first to head first. It is a manual procedure that is recommended by national guidelines for breech presentation of a pregnancy with a single baby, in order to enable vaginal delivery. It is usually performed late in pregnancy, that is, after 36 gestational weeks, preferably 37 weeks, and can even be performed in the early stages of childbirth.

Labor induction is the process or treatment that stimulates childbirth and delivery. Inducing (starting) labor can be accomplished with pharmaceutical or non-pharmaceutical methods. In Western countries, it is estimated that one-quarter of pregnant women have their labor medically induced with drug treatment. Inductions are most often performed either with prostaglandin drug treatment alone, or with a combination of prostaglandin and intravenous oxytocin treatment.

A hysterotomy is an incision made in the uterus. This surgical incision is used in several medical procedures, including during termination of pregnancy in the second trimester and delivering the fetus during caesarean section. It is also used to gain access and perform surgery on a fetus during pregnancy to correct birth defects, and it is an option to achieve resuscitation if cardiac arrest occurs during pregnancy and it is necessary to remove the fetus from the uterus.

Antepartum bleeding, also known as antepartum haemorrhage (APH) or prepartum hemorrhage, is genital bleeding during pregnancy after the 28th week of pregnancy up to delivery.

Cervical dilation is the opening of the cervix, the entrance to the uterus, during childbirth, miscarriage, induced abortion, or gynecological surgery. Cervical dilation may occur naturally, or may be induced surgically or medically.

<span class="mw-page-title-main">Uterine rupture</span> Medical condition

Uterine rupture is when the muscular wall of the uterus tears during pregnancy or childbirth. Symptoms, while classically including increased pain, vaginal bleeding, or a change in contractions, are not always present. Disability or death of the mother or baby may result.

<span class="mw-page-title-main">Prelabor rupture of membranes</span> Medical condition

Prelabor rupture of membranes (PROM), previously known as premature rupture of membranes, is breakage of the amniotic sac before the onset of labor. Women usually experience a painless gush or a steady leakage of fluid from the vagina. Complications in the baby may include premature birth, cord compression, and infection. Complications in the mother may include placental abruption and postpartum endometritis.

<span class="mw-page-title-main">Complications of pregnancy</span> Medical condition

Complications of pregnancy are health problems that are related to, or arise during pregnancy. Complications that occur primarily during childbirth are termed obstetric labor complications, and problems that occur primarily after childbirth are termed puerperal disorders. While some complications improve or are fully resolved after pregnancy, some may lead to lasting effects, morbidity, or in the most severe cases, maternal or fetal mortality.

<span class="mw-page-title-main">Placenta accreta spectrum</span> Medical condition

Placenta accreta occurs when all or part of the placenta attaches abnormally to the myometrium. Three grades of abnormal placental attachment are defined according to the depth of attachment and invasion into the muscular layers of the uterus:

  1. Accreta – chorionic villi attached to the myometrium, rather than being restricted within the decidua basalis.
  2. Increta – chorionic villi invaded into the myometrium.
  3. Percreta – chorionic villi invaded through the perimetrium.

Caesarean delivery on maternal request (CDMR) is a caesarean section birth requested by the pregnant woman without a medical reason.

<span class="mw-page-title-main">Vaginal delivery</span> Delivery through the vagina

A vaginal delivery is the birth of offspring in mammals through the vagina. It is the most common method of childbirth worldwide. It is considered the preferred method of delivery, with lower morbidity and mortality than caesarean sections (C-sections).

<span class="mw-page-title-main">Monoamniotic twins</span> Identical twins sharing the same amniotic sac in the womb

Monoamniotic twins are identical or semi-identical twins that share the same amniotic sac within their mother's uterus. Monoamniotic twins are always monochorionic and are usually termed Monoamniotic-Monochorionic twins. They share the placenta, but have two separate umbilical cords. Monoamniotic twins develop when an embryo does not split until after formation of the amniotic sac, at about 9–13 days after fertilization. Monoamniotic triplets or other monoamniotic multiples are possible, but extremely rare. Other obscure possibilities include multiples sets where monoamniotic twins are part of a larger gestation such as triplets, quadruplets, or more.

The Human Microbiome Project (HMP), completed in 2012, laid the foundation for further investigation into the role the microbiome plays in overall health and disease. One area of particular interest is the role which delivery mode plays in the development of the infant/neonate microbiome and what potential implications this may have long term. It has been found that infants born via vaginal delivery have microbiomes closely mirroring that of the mother's vaginal microbiome, whereas those born via cesarean section tend to resemble that of the mother's skin. One notable study from 2010 illustrated an abundance of Lactobacillus and other typical vaginal genera in stool samples of infants born via vaginal delivery and an abundance of Staphylococcus and Corynebacterium, commonly found on the skin surfaces, in stool samples of infants born via cesarean section. From these discoveries came the concept of vaginal seeding, also known as microbirthing, which is a procedure whereby vaginal fluids are applied to a new-born child delivered by caesarean section. The idea of vaginal seeding was explored in 2015 after Maria Gloria Dominguez-Bello discovered that birth by caesarean section significantly altered the newborn child's microbiome compared to that of natural birth. The purpose of the technique is to recreate the natural transfer of bacteria that the baby gets during a vaginal birth. It involves placing swabs in the mother's vagina, and then wiping them onto the baby's face, mouth, eyes and skin. Due to the long-drawn nature of studying the impact of vaginal seeding, there are a limited number of studies available that support or refute its use. The evidence suggests that applying microbes from the mother's vaginal canal to the baby after cesarean section may aid in the partial restoration of the infant's natural gut microbiome with an increased likelihood of pathogenic infection to the child via vertical transmission.

Trial of labor after caesarean (TOLAC) is the term for an attempted birth in a patient who has had a previous caesarean section. It may result in a successful VBAC (vaginal birth after caesarean) or a repeat caesarean section. In approximately 20-40% of TOLACs, a caesarean is performed. TOLAC is recommended when a patient has had one previous caesarean section using a low transverse uterine incision. The main risks of TOLAC are emergency caesarean section and uterine rupture.

<span class="mw-page-title-main">Uterine niche</span> A medical disorder of the uterus

A uterine niche, also known as a Cesarean scar defect or an isthmocele, is an indentation of the myometrium at the site of a cesarean section with a depth of at least 2 mm.

References

  1. 1 2 3 4 5 6 7 8 9 10 11 12 "Birth After Previous Caesarean Birth, Green-top Guideline No. 45" (PDF). Royal College of Obstetricians and Gynaecologists. February 2007. Archived from the original (PDF) on 2014-12-07.
  2. 1 2 "Vaginal Birth after Cesarean (VBAC)". American Pregnancy Association. Archived from the original on 2012-06-21. Retrieved 2012-06-16.
  3. 1 2 3 Vaginal birth after C-section (VBAC) guide, Mayo Clinic
  4. 1 2 3 4 5 American Congress of Obstetricians and, Gynecologists (Aug 2010). "ACOG Practice bulletin no. 115: Vaginal birth after previous cesarean delivery". Obstetrics and Gynecology. 116 (2 Pt 1): 450–63. doi:10.1097/AOG.0b013e3181eeb251. PMID   20664418.
  5. 1 2 3 4 5 "NIH Vaginal Birth After Cesarean (VBAC) Conference - Panel Statement". NIH Consensus Development Program. March 8–10, 2010. Retrieved 2012-06-16.
  6. ↑ "Vaginal Birth After Cesarean: New Insights: Structured Abstract". Ahrq.gov. 16 September 2010.
  7. ↑ "Page Not Found". www.acog.org. Archived from the original on July 23, 2010.{{cite web}}: Cite uses generic title (help)
  8. 1 2 3 "Maternal, Infant, and Child Health—Healthy People". Healthypeople.gov. 13 September 2012.
  9. ↑ https://www.ncbi.nlm.nih.gov/books/NBK507844/
  10. ↑ "Guideline Synthesis: Vaginal Birth After Cesarean (VBAC)". National Guideline Clearinghouse. Archived from the original on 2012-03-20. Retrieved 2012-06-16.
  11. ↑ Lanneau, Grainger S.; Muffley, Patrick; Magann, Everett F. (2009). "Cesarean Birth: Surgical Techniques". The Global Library of Women's Medicine. doi:10.3843/GLOWM.10133. ISSN   1756-2228.
  12. 1 2 American Congress of Obstetricians and Gynecologists (ACOG). "Guideline on Vaginal birth after previous cesarean delivery: Major Recommendations". guideline.gov. Archived from the original on 2008-01-15. Retrieved 2008-02-09.
  13. ↑ ACOG Practice Bulletin Number 115, August 2010
  14. ↑ Queensland Maternity; Neonatal Clinical Guidelines Program (November 2009). "Queensland Maternity and Neonatal Clinical Guideline: Vaginal birth after caesarean section (VBAC)" (PDF). Archived from the original (PDF) on 30 April 2012. Retrieved 22 September 2012.{{cite journal}}: Cite journal requires |journal= (help)
  15. ↑ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8032534/
  16. 1 2 3 "Vaginal Birth After Cesarean: New Insights". Agency for Healthcare Research and Quality. March 2010. Retrieved 2012-06-16.
  17. ↑ https://www.ontariomidwives.ca/sites/default/files/2017-06/Thinking-about-VBAC-English.pdf
  18. ↑ "NCHS Data Brief: Recent Trends in Cesarean Delivery in the United States Products". Centers for Disease Control and Prevention. March 2010. Retrieved 2012-06-16.
  19. ↑ "Cesarean births, repeat (percent)—Health Indicators Warehouse". Healthindicators.gov. Archived from the original on 2012-03-23. Retrieved 2011-08-15.
  20. ↑ "Rates for Total Cesarean Section, Primary Cesarean Section and Vaginal Birth After Cesarean Section (VBAC), United States, 1989–2006." Archived February 17, 2013, at the Wayback Machine Childbirth Connection Archived 2008-11-02 at the Wayback Machine , 2008. Retrieved 25 September 2008.
  21. ↑ McMahon MJ, Luther ER, Bowes WA, Olshan AF (1996). "Comparison of a Trial of Labor with an Elective Second Cesarean Section". New England Journal of Medicine. 335 (10): 689–695. doi: 10.1056/NEJM199609053351001 . PMID   8703167.
  22. ↑ "Vaginal Birth After Cesarean: New Insights: Structured Abstract". Ahrq.gov. 16 September 2010.
  23. ↑ "Page Not Found". www.acog.org. Archived from the original on July 23, 2010.{{cite web}}: Cite uses generic title (help)
  24. ↑ "Rates of Cesarean Delivery - United States, 1993". Centers for Disease Control and Prevention. Retrieved 2012-06-16.
  25. ↑ McMahon MJ, Luther ER, Bowes WA, Olshan AF (September 1996). "Comparison of a trial of labor with an elective second cesarean section". New England Journal of Medicine. 335 (10): 689–95. doi: 10.1056/NEJM199609053351001 . PMID   8703167.
  26. ↑ Int J Gyn Obs; 1999; vol 66, p. 197
  27. ↑ "Cesarean births, repeat (percent)". Health Indicators Warehouse. Archived from the original on 2012-03-23. Retrieved 2012-06-16.
  28. ↑ "ACOG - Ob Gyns Issue Less Restrictive VBAC Guidelines". Archived from the original on 2012-06-05. Retrieved 2012-07-23.
  29. ↑ "2020 Topics & Objectives: Maternal, Infant, and Child Health". U.S. Department of Health and Human Services. Retrieved 2012-06-16.
  30. ↑ American Congress of Obstetricians and Gynecologists (ACOG). "Guideline on Vaginal birth after previous cesarean delivery". guideline.gov. Archived from the original on 2008-01-15. Retrieved 2008-02-09.
  31. ↑ Zweifler J, Garza A, Hughes S, Stanich MA, Hierholzer A, Lau M (2006). "Vaginal birth after cesarean in California: before and after a change in guidelines". Ann Fam Med. 4 (3): 228–34. doi:10.1370/afm.544. PMC   1479438 . PMID   16735524.
  32. ↑ Rita Rubin (24 August 2005). "Battle lines drawn over C-sections". USA Today. Retrieved 2008-02-09.
  33. ↑ "Vaginal Birth After Cesarean Calculator". Agency for Healthcare Research and Quality. 2013-10-24. Retrieved 2013-07-10.
  34. ↑ Kennare R, Tucker G, Heard A, Chan A (2007). "Risks of adverse outcomes in the next birth after a first cesarean delivery". Obstet Gynecol. 109 (2 Pt 1): 270–6. doi:10.1097/01.AOG.0000250469.23047.73. PMID   17267823. S2CID   5101397.
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