Changes in Episiotomy Practice: Evidence-based Medicine in Action

Justin R Lappen; Dana R Gossett

Disclosures

Expert Rev of Obstet Gynecol. 2010;5(3):301-309. 

In This Article

The Building Controversy: Episiotomy & Severe Perineal Lacerations

The widespread adoption of episiotomy was not without objections. As early as 1948, Kaltreider and Dixon reported a large series of severe obstetric lacerations and noted their association with midline episiotomy.[6] However, it was not until the late 1970s and early 1980s that a significant body of work began to be published on the potential complications of episiotomy. In 1983, Thacker and Banta produced an excellent review of all the published data from 1860 to 1980 and concluded that there was poor evidence to support the routine use of episiotomy.[4] They found no evidence to suggest that episiotomy effectively reduces severe perineal lacerations or pelvic relaxation, and no evidence of benefit to the neonate. In contrast, they highlighted the risks of episiotomy including increased maternal blood loss, increased postpartum pain and increased dyspareunia. They concluded that there was a need for additional research, but that the routine use of episiotomy was unjustified and the risks of the procedure had been largely overlooked. Following their publication, there were an increasing number of prospective studies of episiotomy, as well as a greater focus on its risks.

With early evidence questioning the protective effect of episiotomy, further studies began to evaluate and compare 'routine' episiotomy (performed for essentially all nulliparous parturients) and 'restrictive' episiotomy (performed at provider discretion for maternal or fetal indications). A small study in 1984 compared routine use of episiotomy with more limited use in 181 nulliparous women.[7] The authors found that outcomes for women in both groups were generally similar, but that in the group for whom episiotomy was restricted, 21% had an intact perineum, and these women had the best outcomes with respect to pain and healing postpartum. The authors questioned the routine use of episiotomy; however, they concluded that, "the final decision (regarding episiotomy) can be made only by the accoucheur at the time of imminent delivery". Another small prospective study published in 1987 compared selective versus routine use of episiotomy.[8] This nonrandomized trial compared two groups of women: the first group were delivered by a single author using episiotomy only for fetal distress or operative vaginal delivery, and the second group were delivered by residents "at their own discretion". They found a significant decline in third and fourth degree perineal lacerations with 'selective' use of episiotomy. In fact, no severe lacerations occurred in any woman who had not had an episiotomy.

A large observational study published in Obstetrics and Gynecology in 1989 reviewed almost 3000 deliveries, and noted that while certain patient characteristics (nulliparity, larger infant birth weight) increased the risk of severe (third or fourth degree) lacerations, the greatest increase in risk was related to performance of a midline episiotomy, with an odds ratio (OR)of 8.9 compared with no episiotomy.[9] Interestingly, delivery by a physician, rather than by a trained midwife, also increased the risk of severe laceration more than twofold. A large review of historical data published in 1990 (using data from 1959 to 1966) showed a four- to 12-fold increase in severe perineal lacerations among women undergoing midline episiotomy.[10] The authors concluded that the risks of episiotomy should be evaluated in a randomized clinical trial.

Other studies continued to show an association of midline episiotomy and severe perineal lacerations.[11–14] These investigators found that the most significant modifiable factor related to third and fourth degree lacerations was midline episiotomy, and they recommended curtailing its routine use.

In the aforementioned studies conducted in the USA, the vast majority of patients had midline episiotomies. However, several additional studies performed outside the USA examined the role of mediolateral episiotomy in prevention of severe perineal lacerations. The Argentine Episiotomy Trial, a large prospective randomized trial conducted from 1990 to 1992, found that while overall rates of third and fourth degree lacerations were low, there was a small decline when episiotomy use was restricted.[15] Furthermore, they found reduced rates in need for any repair, in postoperative pain, and in healing complications and dehiscence in the 'restricted' group. Their rates of episiotomy were 83% in the 'routine' group and 30% in the 'restricted' group. They concluded that routine episiotomy should be abandoned, and that rates over 30% could not be justified.

More recently, two large retrospective studies evaluating risk factors for severe obstetric lacerations reached conflicting conclusions regarding the impact of mediolateral episiotomy. In 2006, Baumann and colleagues published a series of more than 40,000 deliveries in Germany where anal sphincter laceration had occurred (5.2% of all deliveries during the study period).[16] In the logistic regression analysis, the risk factors most strongly associated with anal sphincter laceration included episiotomy and forceps delivery with ORs of 3.23 and 2.68, respectively. The authors concluded that iatrogenic factors, namely episiotomy and operative vaginal delivery, place a parturient at the highest risk of severe obstetric laceration. Conversely, a population-based retrospective series of over 284,000 deliveries from the Dutch National Obstetric Database published in 2001 reported a strong protective effect of mediolateral episiotomy against severe obstetric lacerations (OR: 0.21).[17] The episiotomy rate in this study was 35.1%; however the incidence of third and fourth degree perineal lacerations was lower than published rates in countries of comparable socioeconomic status (1.94 vs 4–5%). The authors of this study concluded that mediolateral episiotomy may serve as a primary method of prophylaxis against severe obstetric lacerations.

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