Examples of VBAC
Guidelines.
Guidelines and protocols for
VBAC have similarities and differences. It may be helpful to
compare them with those of your community. Here
is a listing of a few.
Caesarean Guidelines
*Below is an
example of accepted policies, re VBAC, within the average
Australian Hospital.
I have highlighted my own comments/suggestions in regard to
the rigidness of these current accepted
policies.
VAGINAL BIRTH AFTER
CAESAREAN SECTION (VBAC) POLICY
For the majority of women with a
previous Caesarean birth a trial of labour should be
encouraged.
Less morbidity is encountered in
women with successful VBAC compared with those having an
elective repeat Caesarean birth. There are fewer blood
transfusions, fewer postpartum infections and shorter
hospital stays and have no increased perinatal
mortality:(Obstetric and Gynaecology clinics of North
America 26(2) 295-304 1999 Jun).
A woman with a prior Caesarean is
at increased risk regardless of her mode of
birth.
A failed VBAC (non-elective
Caesarean section in labour) has a higher rate of maternal
and neonatal morbidity than a successful VBAC or an elective
repeat Caesarean.
The likelihood of uterine rupture
with attempted VBAC is 0.5%. (0.2% uterine rupture, 1.1%
asymptomatic dehiscence from case control studies). The risk
of hysterectomy and perinatal death from uterine rupture are
0.05% and 0.07% respectively in hospitals equipped to
provide rapid laparotomy. (Australian VBAC study) Major
uterine rupture, before or during labour, after a classical
Caesarean section is 5%.
ANTENATAL
MANAGEMENT
An ultrasound scan should be
performed to check placental localisation to look for
abnormal placentation.
ABSOLUTE CONTRAINDICATIONS TO
VBAC
1. Previous classical caesarean
section
2. Previous inverted T uterine
incision.
3. Previous uterine rupture.
I agree with these first three,
but point out that even in this rare situation a minority of
women may opt for VBAC, recognising the greater risk. Their
right to autonomy must be respected, as well as a hospital's
right to feel protected from litiginous clients. *Suggestion
- in such a special case a more detailed consent form could
be used - see the HBAC Consent Form on this website.
4. Previous cephalo-pelvic
disproportion (CPD) with anticipation of CPD in the current
pregnancy. In order to make this diagnosis; the fetus must
have been occipito anterior (OA) position, with secondary
arrest of progress, and with significant moulding and caput
of the fetal head. Clinical pelvimetry examination should be
used to confirm a small or abnormally shaped maternal
pelvis, and the fetus must be anticipated to be comparable
or larger in size than the previous baby.
CPD is not a reason to repeat
Caesar. The following trial looks exactly at the group
excluded by this policy.
Impey L. and O'Herlihy C. First delivery after caesarean
delivery for strictly defined cephalopelvic disproportion.
Obstet Gynecol 1998;92:799-803.
68% delivered vaginally in the next pregnancy, 47% with a
larger baby. Of 15 women previously delivered by caesarean
at full dilatation 11 (73%) delivered vaginally. In 19
patients pelvimetry had been performed. In 11 (63%)
dimensions were judged to be abnormal. All underwent trial
of labour and 6 (55% - including two with larger babies)
delivered vaginally. - And this trial is a very important
and well known VBAC trial.
Phelan et al. Vaginal birth after
cesarean. AMJOG 1987;157:1510-5.
"Previous indication for cesarean birth bears only little
relationship to the subsequent successful vaginal
delivery".
75% of women with previous cesarean for CPD/failure to
progress delivered vaginally.
*This study looks a group commonly
called "CPD" . Jongen VHWM et al.
"Vaginal delivery after previous caesarean section for
failure of the second stage of labour". BJOG
1998;105:1079-81.
82 (80%) of 103 women with previous delay in descent in
second stage delivered vaginally, including 41 (75%) of 55
who had a history of failed instrumental
delivery.
Where is the evidence that clinical
pelvimetry is useful where there is evidence that
radiological pelvimetry just increases Caesar rates and is a
poor predictor of the outcome of labour? (Thubusi et al.
BJOG 1993; 100:421-4).
The baby's weight is also not
relevant.
Flamm BL and Goings JR. "Vaginal birth after caesarean
section: Is suspected fetal macrosomia a
contra-indication."
4000-4499 range, 139 of 240 patients (58%) delivered
vaginally. Greater than 4500g, 43% delivered vaginally.
Comparison with control group of 301 women with no previous
uterine surgery and macrosomia, showed no significant
difference in perinatal or maternal morbidity.
4. Lack of maternal
cooperation.
*Suggestion - that cooperation
is the wrong word as it has a sense of misbehaviour. It is
important for a woman to take responsibility and be informed
re both VBAC and caesarean birth.
Please note, lack of maternal
agreement is also a good reason
not
to do a caesarean.
5. Development since the previous
delivery of a strong indication for elective Caesarean
section
?? - This is a very unspecific
guideline, which makes if difficult to research the
literature. This just comes across as a "getout" clause, and
such a clause is not present in either the ACOG or SGOC
guidelines.
RELATIVE CONTRAINDICATIONS TO
VBAC
1. More than two previous Caesarean
sections.
SCOG guidelines, which are
above, state... "Labour and vaginal delivery in women with
more than one previous transverse low segment incision is an
acceptable option, although there are less data
available."
ACOG guidelines, also above, state
that
"a woman who has two, or more, previous c/section
deliveries with lower transverse uterine incisions, who has
no other contraindications, and who wishes to attempt
vaginal birth, should not be discouraged from doing
so".
2. Non cephalic presentation
I understand that this may
alter once findings of the term breech trial are digested,
in which VBAC women did participate, but at the moment
limited evidence suggests VBAC breech birth is a reasonable
option.
"Obstetric Myths vs Research
Realities" by Henci Goer. (Pages 111 &endash; 112)
Primiparas, nonfrank breeches, and VBAC candidates should
not be routinely excluded from vaginal birth. (Abstracts
1-3, 5, 41-43)
An alternative to elective
c/section at 38weeks gestation, may be to wait until the due
date to be sure the baby is not going to turn - some babies
do (they've even been known to turn during labour, though
this is not very likely).
Another alternative is ECV (turning the baby manually,
externally. Done by the Obstetrician late in pregnancy).
There are also exercises to try - raising the pelvis above
the head for a few minutes (talk to your caregiver about
these positions before trying) or using sound, or light, to
encourage the baby to turn. The mother plays the music, or
places the light/torch (in a darkened room) on her belly
next to the baby's head, then slowly (very, very slowly)
moves it downwards towards where she wants her baby's head
to be - in the perfect head-down position for birth. It may
spike the baby's interest, and the baby may follow it's
curiosity downwards... It has supposedly worked, and is
worth a try.
3. Significant previous post
Caesarean section sepsis.
Counselling with regards to the
surgical and anaesthetic risks, increased thromboembolic
disease and Respiratory Distress Syndrome in the neonate
versus the risks of VBAC should be provided and carefully
documented in the case notes.
There is a wonderful document,
written by an Obstetrician by the name of Dr. Hill that
would be a good 'handout' for VBAC women (it's address on
the web is http://www.obgyn.net/women/articles/VBAC_dah.htm).
It explains VBAC and c/section birth in simple language,
listing the pros and cons of each method. Maybe a summarised
version, with permission, or something similar would be
valuable.
The decision to proceed with
induction of labour in women with a previous Caesarean
section should be discussed antenatally with the Senior
Registrar/Consultant.
Induction of labour decreases the
success rate of VBAC.
Women should be informed that
it also affects the risks involved. All women undergoing
induction/augmention should be made aware of the increased
risks &endash; that it is no longer 0.5 &endash; 1% as
quoted earlier.
Many women find it a really
difficult time around the due date.
*Suggestion - that a support group, such as Birthrites:
Healing After Caesarean Inc. can have a very positive role
at this time, helping the doctors who would naturally be
trying to avoid "social" induction.
INTRAPARTUM
MANAGEMENT
Patients who have had a previous
Caesarean section are excluded from the Family Birth
Centre.
Patients are being denied the
right to choose where they wish to birth. Their options are
being limited in this way.
The patient should be advised to
present to Delivery Suite early in labour.
Intravenous access should be
established and blood taken for a group and hold serum or
cross matching if appropriate.
A good question would be "Are
there resident medical staff at your hospital, or do the
midwives put in the IV lines? How long it would take to put
in an IV line should an emergency occur?" It may only be a
matter of a few minutes and the patient may be comfortable
with this short delay. It's all about informed decision
making. The pros and cons of an IV bung should be explained,
and the psychological impact of the necessity for IV access
(fear?) should be acknowledged.
The patient should be fasted.
Most caesars are spinals. Most
women don't want to eat in labour so proscriptive rules like
this just damage the relationship between the women and
carers.
*Suggestion - that with an expected VBAC rate of 80% that it
is probably little different to the Caesar rate for primips
(say 10%) so why have a different rule. It would be more
acceptable to allow a "light diet only in early labour.
Fluids only in established labour". This would include
lollies!
Labour should be monitored using
the partogram and any abnormalities should be notified to
the registrar, who should perform an assessment.
I think it is advisable for
each registrar on the shift to try to meet the woman early
in labour, before any exams are needed, to get to know her
views, to read and discuss her birthplan, talk about her
past experience, to see the woman not the labour. This is
the way to get better outcomes for both 'sides'.
Continuous fetal heart rate
monitoring is mandatory.
Please note the SGOC guidelines
(above) state... "One of the most consistent early signs of
scar dehiscence and/or rupture is an abnormal fetal heart
rate pat-tern. Thus, in cases of induction and/or
augmentation, continuous electronic fetal heart rate
monitoring is advised. Intermittent fetal heart monitoring
is to be reserved for cases in which neither induction nor
aug-mentation with oxytocin is performed.
There are other reputable bodies
that are comfortable with this view in non-induced/augmented
labours. Perhaps auscultation with the doptone every 15
minutes in first stage and after each contraction in second
stage might be a reasonable compromise. This is what they
suggested for the breech trial - and many suggest continuous
monitoring for breeches.
There is no contraindication to
epidural analgesia
Any delay in latent/active phase of
labour or fetal heart rate abnormalities should be discussed
with the consultant Obstetrician on call for Delivery Suite
with a view to Caesarean section.
*Abnormalities in the fetal heart
trace, such as variable or late decelerations, prolonged
fetal bradycardia, may warrant Emergency Caesarean section
without recourse to fetal scalp pH measurement, as they may
be the first signs of scar rupture/dehiscence.
Should oxytocin be required, the
available evidence suggests that its use is associated with
a reduced success of vaginal birth and a doubling of scar
rupture/dehiscence. However, oxytocin may be used with
caution in women with a previous Caesarean section,
following discussion with the consultant Obstetrician on
call for Delivery Suite. :
Induction of labour with
amniotomy/oxytocin and/or Foley catheter may be
performed.
Prostaglandins are not licensed in
Australia for use in-patients with a uterine
scar.
Be vigilant for the symptoms and
signs of scar rupture, which may include:
- Suprapubic tenderness and/or
severe constant abdominal pain which continues between
contractions
- Maternal
tachycardia
- Vaginal bleeding
- Fetal tachycardia or fetal
heart decelerations
- No progress in
labour
- Cessation of
contractions
What about a trial/study on the
feelings of control that a woman attempting a VBAC may
require? A comparison between VBAC, elective caesarean and
emergency caesarean in labour, the reactions of the women
and the feelings of control that they were able to maintain
in each situation. Even just a questionaire &endash; our
group could definitely help with that - See the Birth
Survey on this website.
There are many psychological
ramifications of a caesarean birth. These continue on, if
this mode of delivery was unexpected and considered
undesirable by the mother, during the next pregnancy and
birth. The loss of control, and the fear associated with an
earlier birth experience, may result in the need to maintain
control the next time. The amount of technology involved and
the sterile atmosphere may cause a need for a 'natural'
labour and a reduction in unnecessary interventions. When
women choose a VBAC birth, they tend to be making an
extremely informed choice in doing so, this needs to be
acknowledged and respected. |