4 de fev de 2009

Mitos da Obstetrícia versus Realidade... Capítulo 14: Episiotomia

Fonte: http://www.hencigoer.com/obmyth/epis.html

MITO: um corte bonito e limpo é melhor que uma laceração irregular.

REALIDADE: "Assim como qualquer procedimento cirúrgico, a episiotomia implica em riscos como: perda excessiva de sangue, formação de hematoma e infecção... NÃO HÁ EVIDÊNCIAS de que essa rotina reduza o risco de trauma perineal severo, melhore a cicatrização do períneo, previna trauma fetal ou reduza o risco de incontinência urinária." - Sleep, Roberts, and Chalmers (1989)


- Episiotomias não previnem laceração em direção ou nos esfíncteres anal ou vaginal. Na realidade, lacerações profundas quase nunca ocorrem na ausência de uma episiotomia.

- Mesmo quando corretamente reparadas, lacerações no esfíncter anal podem causar problemas crônicos como dor no ato sexual e incontinência fecal ou de gases em idade mais avançada. Em adição, injúria anal predispõe à fístulas retovaginais.

- Se uma mulher nunca passou por uma episiotomia, é possível que tenha uma laceração pequena, mas, com raras exceções, a laceração pode ser pior que uma episiotomia.

- Episiotomia não previne contra relaxamento (ou queda - nota da Bart) da musculatura do assoalho pélvico. Assim, ela não previne contra incontinência urinária ou melhora a satisfação sexual.

- Uma episiotomia não é mais fácil de reparar que uma laceração.

- Uma episiotomia não cicatriza melhor que laceração.

- Episiotomias não são menos dolorosas que lacerações. Elas podem, inclusive, causar problemas prolongados como dor, especialmente no ato sexual.

- Episiotomias não previnem injuries no nascimento, nem danos à cabeça do bebê.

- Episiotomia aumenta a perda de sangue. - Como qualquer outro procedimento cirúrgico, uma episiotomia pode levar a infecção, incluindo infecção fatal.

- Anestesia peridural aumenta a necessidade de episiotomia. Ela também aumenta a probabilidade de parto a fórceps. Parto a fórceps aumenta a ocorrência de episiotomia e lacerações profundas.

- A posição de litotomia (mulher deitada em decúbito dorsal com as pernas em aparadores - nota da Bart) aumenta a necessidade de episiotomia, provavelmente porque o períneo está estirado. - A filosofia de atendimento ao parto, as técnicas, experiência e habilidade da equipe que auxilia a mulher são os maiores determinantes no sucesso da proteção do períneo.

- Algumas técnicas de redução de trauma perineal que têm sido avaliadas e se mostraram efetivas são: massagem perineal no pré-natal, nascimento suave da cabeça do bebê, apoiando o períneo e mantendo a cabeça do bebê flexionada, deixando sair os ombros um de cada vez, fazendo partos instrumentais sem episiotomia. (Outras técnicas como massagem perineal durante o trabalho de parto ou compressas quentes ainda devem ser estudadas.

- Independente de contrair especificamente a musculatura perineal (como nos os exercícios de Kegel), um programa regular de exercícios para essa musculatura fortalece o assoalho pélvico.

Nota da BART: O texto completo que peguei lá no site citado no item "Fonte" é esse que segue abaixo... Espero um dia traduzi-lo na íntegra. Como ainda não tive tempo, resolvi publicá-lo assim mesmo... Quem tiver como ler um pouco ou muito do Inglês já vai se beneficiando... ;-)


"Routine or prophylactic episiotomy (as opposed to episiotomy for specific indication such as fetal distress) is the quintessential example of an obstetrical procedure that persists despite a total lack of evidence for it and a considerable body of evidence against it. All the authoritative pronouncements in favor of episiotomy descend from a 75-year-old article (DeLee 1920) that produced not a shred of evidence in its support. Most recently, Williams Obstetrics (Cunningham, MacDonald, and Gant 1989) states, "The reasons for [episiotomy's] popularity among obstetricians are clear. It substitutes a straight, neat surgical incision for the ragged laceration that otherwise frequently results. It is easier to repair and heals better than a tear." Human Labor and Birth (Oxorn-Foote 1986) adds that it averts "brain damage" by "lessen[ing] the pounding of the head on the perineum." An earlier edition of William's Obstetrics (Pritchard, MacDonald, and Gant 1985) claims that it reduces the incidence of cystocele (a herniation of the posterior bladder through the anterior rectal wall), rectocele (a herniation of the anterior rectal wall through the posterior vaginal wall), and stress incontinence (involuntary loss of urine in response to laughing, sneezing, etc., although the 1989 edition admits this benefit is unproved). It then lists "important questions for the obstetrician concerning episiotomy," none of which is whether to do one at all. In a branch of medicine rife with paradoxes, contradictions, inconsistencies, and illogic, episiotomy crowns them all. The major argument for episiotomy is that it "protects the perineum from injury," a protection accomplished by slicing through perineal skin, connective tissue, and muscle. Obstetricians presume spontaneous tears do worse damage, but now that researchers have gotten around to looking, every study has found that deep tears are almost exclusively extensions of episiotomies. This makes sense, because as anyone who has tried to tear cloth knows, intact material is extremely resistant until you snip it. Then it rips easily.

By preventing overstretching of the pelvic floor muscles, episiotomies are also supposed to prevent pelvic floor relaxation. Pelvic floor relaxation causes sexual disatisfaction after childbirth (the concern was the male partner, of course, hence, the once-popular "husband's knot," an extra tightening during suturing that made many women's sex lives a permanent misery), urinary incontinence, and uterine prolapse. But older women currently having repair surgery for incontinence and prolapse all had generous episiotomies. In any case, episiotomy is not done until the head is almost ready to be born. By then, the pelvic floor muscles are already fully distended. Nor has anyone ever explained how cutting a muscle and stitching it back together preserves its strength.

Perhaps the most absurd rationale of all is brain damage from the fetal head's "pounding on the perineum." A woman's perineum is soft, elastic tissue, not concrete. No one has ever shown that an episiotomy protects fetal neurologic well-being, not even in the tiniest, most vulnerable preterm infants, let alone a healthy, term newborn (Lobb, Duthie, and Cooke 1986; The 1990, both abstracted below).

Meanwhile, as the authors of this chapter's "Reality" quotation point out, episiotomy, like any other surgical procedure, carries the risk of blood loss, poor wound healing, and infection. Infections are painful. Sutures must be removed to drain the wound, and later the perineum must be restitched. In their literature survey Thacker and Banta (1983, abstracted below) found wound infections and abscess rates ranging from 0.5% to 3%.

Moreover, there are two extremely rare gangrenous infections called necrotizing fasciitis and clostridial myonecrosis reported in the literature. These infections kill many of the women who contract them and maim the survivors. William's Obstetrics (Cunningham, MacDonald, and Gant 1989) says of them in boldface type, "Mortality is virtually universal without surgical treatment, and it approaches 50% even if aggressive excision is performed." While these infections are rare, they make a substantial contribution to maternal mortality. Between 1969 and 1976 they caused 27% (3/11) of the maternal deaths in Kern County, California (Ewing, Smale, and Eliot 1979). A fourth woman survived, spending 23 days in the hospital. Shy and Eschenbach (1979) report on four cases in King County, Washington, between 1969 and 1977. Three women died, representing 20% of the maternal mortality rate during those years. The fourth woman survived, losing most of her vulva to surgical excision and debridement. Nine additional cases are also reported, of which seven women died and two had extensive surgeries and prolonged hospitalizations (Soper 1986; Sutton et al. 1985; Ewing, Smale and Elliott 1979; Golde and Ledger 1977). Since all fatalities were in healthy women who had uncomplicated labors, their episiotomies literally killed them!

Obviously an infection could start in a repaired tear, but substantial numbers of women who do not have episiotomies have intact perineums. There also appears to be an association between the extent of the wound and these deadly infections. Nine of the 17 cases, or more than half, involved third- or fourth-degree injuries (tears or deliberate cuts into or through the anal sphincter). It bears repeating that women with no episiotomy hardly ever suffer deep tears.

Despite two decades of evidence to the contrary, most doctors and some midwives still cling to the liberal use of episiotomy. The Canadian multicenter randomized controlled trial (Klein et al. 1992, abstracted below) could not get doctors to abandon it. Episiotomy rates were reduced by only one-third in the so-called restricted arm of the study. More than half of primiparas in the restricted group (57%) still had episiotomies, as did nearly one-third of multiparas (31%). "The intensity with which physicians adhere to the belief that episiotomy benefits women is well illustrated by the behavior of many of the participating physicians in this trial. Many were unwilling or unable to reduce their episiotomy rate according to protocol."

If episiotomy lacks scientific rationale, what drives its use? As Robbie Davis-Floyd (1992), medical anthropologist, writes, episiotomy fits underlying cultural beliefs about women and childbirth. It reinforces beliefs about the inherent defectiveness and untrustworthiness of the female body and the dangers this poses to women and babies. So DeLee (1920), imbued with these beliefs, writes:

Labor has been called, and still is believed by many, to be a normal function. . . . [Y]et it is a decidedly pathologic process. . . . If a woman falls on a pitchfork, and drives the handle through her perineum, we call that pathologic--abnormal, but if a large baby is driven through the pelvic floor, we say that is natural, and therefore normal. If a baby were to have its head caught in a door very lightly, but enough to cause cerebral hemorrhage, we would say that it is decidedly pathologic, but when a baby's head is crushed against a tight pelvic floor, and a hemorrhage in the brain kills it, we call this normal.

Having invented the problem, he proffers a solution: as soon as the head passes through the dilated cervix, anesthetize the woman with ether, cut a large mediolateral episiotomy, pull the baby out with forceps, and manually remove the placenta, then give the woman scopolamine and morphine for the lengthy repair work and to "prolong narcosis for many hours postpartum and to abolish the memory of labor." Repair involves pulling down the cervix with forceps to examine it and stitch any tears and laboriously reconstructing the vagina to restore "virginal conditions." While few modern obstetricians are willing to go as far as DeLee, these beliefs about women still pervade obstetrics, and they fuel episotomy.

Episiotomy serves another purpose. Davis-Floyd observes that surgery holds the highest value in the hierarchy of Western medicine, and obstetrics is a surgical specialty. Episiotomy transforms normal childbirth--even natural childbirth in a birthing suite--into a surgical procedure.

Davis-Floyd also points out that episiotomy, the destruction and reconstruction of women's genitals, allows men to control the "powerfully sexual, creative, and male-threatening aspects of women." This is what lurks behind DeLee's emphasis on surgically restoring "virginal conditions." It also partially explains why most trials of episiotomy have been done in European countries where normal birth is conducted by female midwives, not in the U.S. or Canada, where birth is conducted (until recently) by male doctors: women are not subconsciously threatened by birth. Klein et al. attribute the greater success of a British "restricted" versus "liberal" use of episiotomy trial in achieving fewer episiotomies and more intact perineums to "the increased comfort of British midwives in attending births with the intention of preserving an intact perineum."

In short, routine episiotomy has a ritual function but serves no medical purpose. If any reader believes otherwise, I challenge him or her to find a credible study done in the past 15 years that supports those beliefs.

Note: There are two types of episiotomies: midline or median (straight down toward the rectum) and mediolateral (down and off to one side) U.S. and Canadian doctors usually do midline episiotomies while European doctors and midwives prefer mediolateral ones. According to Williams Obstetrics,(Cunningham, MacDonald, and Gant 1989) midline episiotomies are less painful, heal better, are less likely to cause dyspareunia (coital pain), and cause less blood loss, but they are more likely to extend into the rectum. Mediolateral episiotomies are the opposite. Because of these differences, I will note which type was performed after the abstract citation.

Because of these differences, I have excluded studies of mediolateral episiotomy where data were available on median episiotomies. For many areas of interest, however, they were unavailable. (For those living in countries where mediolateral episiotomy is the norm, conclusions about the benefits and risks of episiotomy were similar regardless of type.) This is because until very recently, U.S. and Canadian doctors were so convinced of episiotomy's value that they did not feel it necessary to test their theory. This was less true of European midwives, and by extension, the doctors with whom they work."


- Episiotomies do not prevent tears into or through the anal sphincter or vaginal tears. In fact, deep tears almost never occur in the absence of an episiotomy. (Abstracts 1-12, 16, 19-20, 23-28)

- Even when properly repaired, tears of the anal sphincter may cause chronic problems with coital pain and gas or fecal incontinence later in life. In addition, anal injury predisposes to rectovaginal fistulas. (Abstracts 11, 15, 21-22)

- If a woman does not have an episiotomy, she is likely to have a small tear, but with rare exceptions the tear will be, at worst, no worse than an episiotomy. (Abstracts 1, 2, 5, 8-10, 14, 16, 24-25)

- Episiotomies do not prevent relaxation of the pelvic floor musculature. Therefore, they do not prevent urinary incontinence or improve sexual satisfaction. (Abstracts 1-4, 7, 12-16)

- Episiotomies are not easier to repair than tears. (Abstracts 1, 3, 9)

- Episiotomies do not heal better than tears. (Abstracts 1, 5-6, 12-15, 21)

- Episiotomies are not less painful than tears. They may cause prolonged problems with pain, especially pain during intercourse. (Abstracts 1, 2, 7, 12, 14-15, 19-20)

- Episiotomies do not prevent birth injuries or fetal brain damage. (Abstracts 1, 3, 5-7, 12, 14, 17-18, 27)

- Episiotomies increase blood loss. (Abstracts 1, 12, 19)

- As with any other surgical procedure, episiotomies may lead to infection, including fatal infections. (Abstracts 1, 12, 19, 22)

- Epidurals increase the need for episiotomy. They also increase the probability of instrumental delivery. Instrumental delivery increases both the odds of episiotomy and deep tears. (Abstracts 5, 11-12, 21, 25-26)

- The lithotomy position increases the need for episiotomy, probably because the perineum is tightly stretched. (Abstracts 10, 25, 27)

- The birth attendant's philosophy, technique, skill, and experience are the major determinants of perineal outcome. (Abstracts 2, 5-7, 9-10, 25-27)

- Some techniques for reducing perineal trauma that have been evaluated and found effective are: prenatal perineal massage, slow delivery of the head, supporting the perineum, keeping the head flexed, delivering the shoulders one at a time, and doing instrumental deliveries without episiotomy. (Others, such as perineal massage during labor or hot compresses have yet to be studied.) (Abstracts 23-24, 28)

- Independent of specifically contracting the pelvic floor muscles (Kegels), a regular exercise program strengthens the pelvic floor. (Abstract 13)

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