Vaginal birth after caesarean

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Vaginal birth after caesarean (VBAC) refers to the practice of delivering a baby vaginally (naturally) after a previous baby has been delivered through caesarean section (surgically).[1] . A caesarian section leaves a scar in the wall of the uterus. This scar is weaker than the normal uterine wall, so if the woman goes in labor in a subsequent pregnancy there is a higher than normal risk of a ruptured uterus. Because of this risk an attempt at normal vaginal delivery was for most of the 20th century considered unacceptably risky. This opinion was challenged by many studies showing that many women with previous caesaran sections did have successful vaginal deliveries. In the 1980s and 1990s there was a strong movement to encourage attempts at vaginal delivery after caesarean section. Mothers with a previous 'bikini cut' or lower uterine segment cesarian were considered the best candidates, as that part of the uterus does not contract during the birthing process. Nevertheless as there was yet no consensus on the management of such births, tactics such as induction of labour were still applied to VBAC candidates. In addition to that ultrasound was not consistently used to monitor the thinning of the lower uterine segment during delivery. Induction led to an increase of uterine ruptures and lack of consistent ultrasound management of the uterine scar thickness led to women with very thin scars to take unacceptable risks. We know now that induction, especially using prostagladins causes chemical changes in the integrety of the uterine body, increasing the chances of adverse effects. In addition studies on the lower uterine segment thickness have shown that if the thickness at the 38th week of the pregnancy has reached a minimum of 4.5mm, which is the same of the unscarred uterus, then the chance of rupture is essentially non existent. Studies in the 1990s confirmed that vaginal delivery after previous caesaran section was riskier than average. The American College of Obstetrics and Gynecology issued subsequent guidelines which identified VBAC as a high-risk delivery requiring the availability of an anesthesiologist, an obstetrician, and an operating room on standby (Int J Gyn Obs; 1999; vol 66, p197). Nevertheless practices such as induction and lack of ultrasound management still continue

In the 1990s the rate at which VBAC was tried fell from 26% to 13%. Many hospitals could not commit to the new guidlines and in addition a number of health insurance companies would not support it. Today only about 10% of eligible women in the United States try a VBAC

According to the American Pregnancy Association, 90% of women who have undergone cesarean deliveries are candidates for VBAC.[2] From 60-80% of women opting for VBAC will successfully give birth vaginally.[2][3]

Contents

[edit] Drawbacks and benefits

The decision to have a trial of VBAC is made by the mother with the advice of her obstetrician. The decision is guided by an assessment of the known risk factors for complications. In general, an attempt at VBAC is safe if there are no other identified risk factors.

Risks of cesarean section include a higher chance of re-hospitalization after birth, infertility, uterine rupture in the next pregnancy, injury to the baby, premature birth and respiratory problems in the baby, as well as bonding and breastfeeding difficulties.[4] The risk of uterine rupture in a VBAC is 0.2% to 1.5%, being on the lower range in cases of lack of induction or any other intervention during childbirth [2]

The risk of infection doubles if vaginal delivery is attempted but results in another cesarean.[2]. All complications of cesarean section are more likely and more severe if it is done as an emergency after a failed attempt at vaginal delivery rather than as a planned operation.

[edit] Eligibility

There are several common methods of determining eligibility. Some common factors include:[3]

  • If the previous caesarean(s) involved a low transverse incision there is less risk of uterine rupture than if there was a low vertical incision, classical incision, T-shaped, inverted T-shaped, or J-shaped incision.
  • A previous successful vaginal delivery (before or after the caesarean section) increases the chances of a successful VBAC.
  • The reason for the previous caesarean section should not be present in the current pregnancy.
  • The more caesarean sections that a woman has had, the less likely she will be eligible for VBAC.
  • The presence of twins will decrease the likelihood of VBAC. Some doctors will still allow VBAC if the twins are positioned properly for birth.
  • VBAC may be ruled out if there are other medical complications (such as diabetes), if the mother is over 40, if she is past her due date, if the baby is in the wrong position, etc.

For women planning to have many children, VBAC may be a better option because repeat caesarean sections get more complicated each time.

[edit] History

VBAC is not uncommon today. The medical practice until the late 1970s was "Once a caesarean, always a caesarean," but a consumer-driven movement supporting VBAC changed the standard medical practice. Rates of VBAC rose in the 80s and early 90s, however they have fallen since.

[edit] See also

[edit] References

  1. ^ Vaginal Birth After Cesarean (VBAC) - Overview, WebMD
  2. ^ a b c d Vaginal Birth after Cesarean (VBAC) : American Pregnancy Association
  3. ^ a b Vaginal birth after C-section (VBAC) guide, Mayo Clinic
  4. ^ (Midwifery Today Winter No 36 page 47 ACOG, 409 12th St SW, Washington DC 20024}

[edit] External links

Retrieved from "http://en.wikipedia.org/wiki/Vaginal_birth_after_caesarean"