|
The rise of cesareans and decline of vaginal
births mark a troubling era of intervention-riddled obstetric practice
worldwide. In the United States the cesarean delivery rate
reached 26.1 percent in 2002 (1),
its highest rate ever, and similar increases are occurring in other
countries (2-6).
Along with a technology-driven society, an anti-vaginal birth movement
seems to be underway in the obstetric community. Higher rates of
electronic fetal monitoring, induction, and epidural analgesia have been
implicated in the rise in cesareans, but other factors are fueling the
trend. Randomized controlled trials may be the best form of evidence,
but they are not all without flaws, and some multicenter trials (7,8)
have pushed professional management guidelines and clinical practice
toward higher cesarean section rates. Promotion for elective cesareans
combined with an anti-vaginal-birth theme has become a popular
educational offering at medical conferences (9).
For women who want a vaginal birth after a
previous cesarean (VBAC) or, horrors, a vaginal breech birth, making an
informed choice in this new obstetric era is difficult indeed. Fearful
doctors warn that "the natural process of labor and delivery is fraught
with hazard" (10),
and others claim "it is time to speak out and say that cesarean section
is a normal birth method"
(11.their
italics). Revised and biased informed consent forms for VBAC downplay
risks of cesareans. So women often get the impression that elective
cesareans are safer![-]() safer than they really are and safer than vaginal
birth; some want the convenience of a scheduled birth. I have my own
bias![-]() not only were my two children born by natural
childbirth, I was "twin A," the breech-presenting offspring of a
successful natural, full-term birth of twins, and 8 years later my
mother repeated the feat with a second pair of twins, "twin A" of whom
was also breech. We would have been cesarean certainties in today's
world.
Anecdotes aside, two new multicenter randomized
controlled trials are getting underway in Canada and
Australia that have the potential, ultimately, to further swell the
numbers of women destined for a cesarean delivery. One of these, by the
Maternal, Infant and Reproductive Health Research Unit (MIRU) of the
University of Toronto, Canada, is a comparison between planned cesarean
section (CS) and planned vaginal birth (VB) for twin pregnancies. Jon
Barrett, principal investigator, described the Twin Birth Study at the
MIRU conference of November 7, 2002, "Choosing Delivery by Caesarean:
Has Its Time Come?" (12).
The study's primary research question is "For twin pregnancies of ![>=]() 32 weeks gestation, where twin A is
presenting vertex, does a policy of planned CS decrease the likelihood
of stillbirth or neonatal mortality or serious morbidity, during the
first 28 days after birth, compared to a policy of planned VB?" The
secondary research question is "For twin pregnancies of ![>=]() 32 weeks gestation, where twin A is
presenting vertex, does a policy of planned CS compared to a policy of
planned VB decrease the risk of problematic urinary or faecal/flatal
incontinence for the mother at 2 years postpartum?" Approximately
120 centers from 27 countries are expected to participate, with a
planned sample size of 2800 pregnancies, 1400 per group (12).
It will be interesting to see how the results compare with those from a
recent meta-analysis by the same Toronto researchers, which concluded,
"there is no evidence to support planned cesarean section for twins,"
although it "may decrease the risk of a low 5-minute Apgar score" (13).
The second study is the ACTOBAC Trial (A
Collaborative Trial of Birth After Caesarean), in which women at term
with a previous cesarean section will be randomized to either a vaginal
birth or a planned cesarean (14).
The Maternal and Perinatal Clinical Trials Unit of the University of
Adelaide, South Australia, with principal investigator Caroline
Crowther, will conduct this trial. The primary hypothesis, described in
the information sheet for health professionals, is that "Planned vaginal
birth after caesarean section compared with planned elective repeat
caesarean is associated with an increased risk of death or serious
adverse outcome for the infant." The secondary hypotheses are that
"Planned vaginal birth after caesarean section compared with planned
elective repeat caesarean is associated with reduced risk of serious
maternal outcomes up to six weeks postpartum; decreased physical
wellbeing in the woman as measured by pain, dyspareunia, urinary or
faecal incontinence and success at breast feeding; (and) decreased
emotional wellbeing in the woman as measured by quality of life,
anxiety, depression, bonding with the infant and relationship with her
partner" (14).
The rising prevalence of cesareans has provoked
outrage (15-18,20-22).
The American College of Nurse-Midwives expressed alarm that "cesarean
section rates are off the charts and women are being duped in thinking
that this is all right" (17).
As the College asserted, "A cesarean should be the last resort, not
merely an option based on convenience or defensive practice" (17).
A strong editorial published by the Association of Women's Health,
Obstetric and Neonatal Nurses suggests that "a revolution" and
system-wide changes in care are needed to return normalcy to
childbearing (18).
Consumer groups are speaking out too (15,20-22)
The International Cesarean Awareness Network, Inc. (ICAN) insists on an
"end to forced cesareans," and "a woman's right to make decisions for
herself and her baby" (20).
ICAN's petition, signed by over 3000 individuals, demanded "an immediate
revision of restrictive and harmful vaginal birth after cesarean (VBAC)
guidelines [19]
published by the American College of Obstetricians and
Gynecologists" (20).
The Coalition for Improving Maternity Services (CIMS), alarmed at the
"overuse" and high rate of cesareans in the United States in 2002 (1),
recently published an important fact sheet, "The Risks of Cesarean
Delivery to Mother and Baby" (21).
In Australia, The Maternity Coalition Inc., a
consumer group that combines CARES SA (Cesarean Awareness Recovery
Education Support South Australia), Birthrites, and Maternity Coalition,
has joined forces in a nationwide campaign to oppose the proposed
ACTOBAC trial, which they fear "will have a huge impact on women's
choice and care in the future" (22).
They claim that the trial is unethical, first, because it will randomize
women to major abdominal surgery in the absence of clinical indications,
and second, because women allocated to the repeat cesarean group who go
into labor spontaneously will receive an emergency cesarean irrespective
of labor progress. The Coalition also claims that the trial "sets women
up to 'fail"' and gives biased information by minimizing risks of
cesarean section. Women in South Australia have a right to
be worried![-]() cesareans in their state jumped to 27.8 percent in
2001, compared with a spontaneous vaginal birth rate of 59.5 percent and
VBAC rate of 22.9 percent (5).
High, too, on the agenda of cesarean birth
proponents, in the literature, and at medical conferences is the topic
of preventing pelvic floor damage and urinary and anal incontinence by
elective cesarean section. (Note that this pelvic floor issue used to be
the reason for propagating universal episiotomy in earlier days, also
without good evidence.) Those who favor maternal choice for elective
primary cesarean delivery cite "compelling" supportive evidence for
pelvic floor damage and incontinence, and justify the procedure by
stressing the risks of vaginal birth over those of cesarean birth (23).
A voice of reason suggests, however, that "these adverse side effects
[from vaginal delivery] may be more the result of how current obstetrics
manages the second stage of labor," and urges more research into such
management practices (24).
Evidence on the vaginal-birth side of the debate demands equal attention
and offers less than compelling evidence for elective cesarean
section.
Studying a cohort of 149 nuns in upstate
New York, Buchsbaum et al concluded that the
prevalence of urinary incontinence "in nulliparous, predominantly
postmenopausal nuns is similar to rates reported in parous,
postmenopausal women" and that "these findings appear to be contrary to
the conventional wisdom that nulliparity protects against stress urinary
incontinence" (25).
They also reported "we are undertaking a study in which findings on
physical examination and urodynamic results from nulliparous nuns will
be compared with those of their parous biological sisters" (25).
An implication of this National Institutes of Health-funded study, which
is recruiting 100 pairs of sisters, could be "a reduced rate of elective
cesarean deliveries" (26).
In a Norwegian study of 15,307 women, the risk
of urinary incontinence was "higher among women who have had cesarean
sections than among nulliparous women and is even higher among women who
have had vaginal deliveries," but "there was no association of
incontinence with mode of delivery in older age groups" (i.e., over
50 years of age) (27).
The authors concluded that "attempts to prevent both any incontinence
and moderate or severe incontinence in the population by encouraging the
use of cesarean section would have limited effect," and that a previous
substudy also "did not show an association between parity and
incontinence after 65 years of age." The results, therefore,
"should not be used as an argument for the increased use of cesarean
delivery" (27).
A recent British study compared 184 primiparas
who had cesarean sections with 100 controls who had a noninstrumental
vaginal birth to determine incidence and severity of anal incontinence
(28).
The authors found that "severe anal incontinence followed elective and
prelabor emergency cesarean," and "the risk after elective cesarean is
comparable to that after noninstrumental vaginal delivery with an intact
perineum," concluding that "our study supports those who argue against
routine elective cesarean delivery" (28).
Similar findings were reported in a large Australian study of 1546
women, in whom pelvic floor morbidity, including anal incontinence,
occurred after cesarean delivery with a prevalence comparable to that
after noninstrumental vaginal birth (29).
The Australian investigators concluded that pregnancy, not childbirth
(unless compounded by instrumental vaginal delivery) was responsible for
the frequency of pelvic floor dysfunction. In a BJOG editorial on the Australian
findings, Grant noted "What is remarkable![...]() is the frequency of pelvic floor dysfunction in
the population. Thus one in eight women who have never been pregnant had
some form of pelvic floor dysfunction, compared with one-half of the
women who had a caesarean section or a spontaneous vaginal delivery and
two-thirds of the women who underwent an instrumental vaginal delivery"
(30).
Meanwhile, in the United States,
what is a woman's chance of having a cesarean delivery? Certainly these
days she's at high risk if she's too big or too small; too early or too
late; too old or too fearful; too tired of being pregnant or too tired
of being in labor; if she's having twins, if she's breech, if she's
previously had a cesarean; or if she's due and so is the weekend,
Christmas, Thanksgiving, or New Year's Eve. Then again, she's also at
risk if her doctor is in doubt, scared of a lawsuit, too busy, going out
of town, or convinced that a cesarean is always safer![...]() the reasons go on.
More cesareans beget more cesareans, and more
cesareans mean more risks to the health of mothers and babies. Bernstein
reminds us "One of the most significant risks of cesarean delivery is
the need for a subsequent cesarean delivery![...]() .If elective cesarean delivery becomes an
acceptable alternative, we may never be able to undo the practice" (24).
Perhaps the return to normal childbirth calls for a revolution
indeed. |
image001.gif
image002.gif
image003.gif