Prevalence and contributing factors of severe perineal damage following episiotomy-assisted vaginal delivery

ObjectiveThis study was conducted to investigate the risk factors of third- and fourth-degree lacerations following vaginal deliveries in Taiwanese women, and to offer clinical guidance for the reduction of severe perineal lacerations.Materials and methodsA total of 1879 women who underwent vaginal deliveries assisted by midline episiotomy at a tertiary hospital were included. Obstetric risk factors were analyzed for women with and without third- and fourth-degree lacerations.ResultsTwo hundred and five deliveries (10.9%) resulted in third- or fourth-degree lacerations. Parity, duration of first and second stages of labor, rate of instrument-assisted vaginal deliveries, the newborn's birth weight and head circumference, and the ratio of the newborn's birth weight to maternal body mass index were significantly different between women with and without severe perineal lacerations. Logistic regression demonstrated that nulliparity (odds ratio = 3.626, p < 0.001), duration of second stage of labor (odds ratio = 1.102, p = 0.044), instrument-assisted vaginal delivery (odds ratio = 4.102, p < 0.001), and newborn's head circumference (odds ratio = 1.323, p < 0.001) were independent risk factors of severe perineal lacerations. Instrument-assisted vaginal delivery was a common independent risk factor for severe lacerations shared between primiparous and multiparous women.ConclusionsWith regard to severe perineal lacerations during vaginal delivery, there are multiple obstetric contributory factors despite routine episiotomy, among them, nulliparity, longer labor duration, greater newborn head circumference, and instrument-assisted vaginal delivery. The latter should only be performed after careful evaluation.     

Risk factors for severe perineal tear: can we do better?

Our aim was to investigate the risk factors associated with severe perineal tears defined as either third- or forth-degree tears and, ultimately, find strategies for prevention. We carried a retrospective analysis of a computerized perinatal database, collected prospectively, from a single county hospital between January 1, 1993 and June 30, 1998. Singleton vaginal vertex deliveries were analyzed for potential risk factors using univariate and multiple logistic regression analysis including all two-way interactions. Severe perineal tear occurred in 1905 (8.2%) of 23,244 vaginal deliveries. In the multiple logistic regression analysis, the following factors carried a significantly higher risk for severe laceration: midline episiotomy, primary vaginal delivery, use of pudendal block, forceps deliveries, and birth weight more than 4000 g. The study of interactions demonstrated that mediolateral episiotomy was associated with an increased risk for severe tear only during the first vaginal delivery, but not during a repeat vaginal delivery. Our data suggest that primary vaginal delivery, fetal weight above 4000 g, and the use of pudendal analgesia can help identify in advance patients at highest risk for severe perineal tear. During the delivery of these patients usage of vacuum (instead of forceps) and restricting the use of midline episiotomy might reduce the incidence of severe perineal tear. In cases where episiotomy seems crucial, the use of a mediolateral episiotomy may reduce the likelihood of severe perineal tear.     

Midline episiotomies: more harm than good?

The association between episiotomy and severe (third- and fourth-degree) perineal lacerations was studied in 24,114 women. The overall rates of severe lacerations were 8.3 and 1.5% for primiparous and multiparous women, respectively. Women who had midline episiotomies were nearly 50 times more likely and women who had mediolateral episiotomies were over eight times more likely to suffer a severe laceration than were women who did not undergo an episiotomy. Severe lacerations were also more common after use of forceps, in occiput transverse and posterior presentations, among women with smaller pelvic outlet measurements or lower prepregnant weight, and with larger fetuses. The same factors that caused a woman to have an increased risk of laceration also made performance of an episiotomy more likely. After statistical adjustment for these risk factors, mediolateral episiotomy was associated with a 2.5-fold reduction in the risk of severe lacerations among primiparous women, and a statistically nonsignificant 2.4-fold increase among multiparous women, compared with no episiotomy. Midline episiotomy was associated with statistically significant 4.2- and 12.8-fold increases in the risk of lacerations among primiparous and multiparous women, respectively. We conclude that the risks and benefits of midline episiotomy should be evaluated in a randomized clinical trial that compares policies of "usual" versus conservative use of episiotomy.     

Selected use of midline episiotomy: effect on perineal trauma

A prospective, nonrandomized controlled study was performed to determine the effect of using midline episiotomy only for mothers who experienced fetal distress and/or operative vaginal delivery. Such a policy resulted in a significant decline in third- and fourth-degree lacerations in nulliparous women. This reduction was most pronounced in nulliparous women delivering infants larger than 3400 g. No third- or fourth-degree laceration occurred without antecedent episiotomy in any woman. A policy of using episiotomy selectively appears to lower the incidence of perineal trauma.     

Management of the perineum during forceps delivery. Association of episiotomy with the frequency and severity of perineal trauma in women undergoing forceps delivery

OBJECTIVE: To examine the association of the frequency and severity of perineal trauma with episiotomy performed at forceps delivery. STUDY DESIGN: This retrospective study analyzed all forceps deliveries at the Semmelweis Women's Hospital Vienna between February 1999 and July 1999. Evaluation of a possible association of episiotomy with the frequency and severity of perineal trauma was the main objective of the study. Episiotomy was not performed routinely and was either midline or mediolateral. RESULTS: In conjunction with forceps delivery episiotomy, 76/87 women (87%) underwent forceps delivery episiotomy; among those, 49/76 (64%) had a mediolateral episiotomy and 27/76 (36%) a midline episiotomy. The frequency and severity of perineal tears were significantly lower in forceps deliveries when an episiotomy was performed. When analyzing the type of episiotomy, the data revealed a statistically significantly lower frequency of perineal trauma when mediolateral episiotomy was performed as compared to midline episiotomy. CONCLUSION: If obstetric indications necessitate forceps delivery, performance of an episiotomy decreases the risk of perineal tears of all degrees. When analyzing the type of episiotomy, mediolateral episiotomy seems to be more protective against perineal trauma in women undergoing forceps delivery.     

Factors predicting severe perineal trauma during childbirth: role of forceps delivery routinely combined with mediolateral episiotomy

OBJECTIVE: Anal sphincter injury and its sequelae are a recognized complication of vaginal childbirth. The aim of the present study was to identify risk factors for third- and fourth-degree perineal tears in patients undergoing either spontaneous or vaginal-assisted delivery by forceps routinely combined with mediolateral episiotomy. STUDY DESIGN: We retrospectively reviewed 5377 vaginal deliveries based on the analysis of the obstetric database and patient records of our department during a 5-year period from 1999 to 2003. Cases and control subjects were chosen randomly and patients' records were reviewed for the following variables: maternal age, parity, gestational age, tobacco use, gestational diabetes or pregnancy-induced hypertension, use of peridural anesthesia, duration of first and second stages of labor, use of mediolateral episiotomy, forceps combined with mediolateral episiotomy, induction of labor, infant head diameter, shoulder circumference, and birth weight. RESULTS: Of 5044 spontaneous vaginal deliveries 32 (0.6%) and of 333 assisted vaginal deliveries 14 (4.2%) patients sustained a perineal defect involving the external sphincter. An univariate analysis of these 46 cases and 155 randomly selected control subjects showed that low parity (P = .003; Mann-Whitney U test), prolonged first and second stages of labor (P = .001, P = .001), high birth weight (P = .031), episiotomy (P = .004; Fisher exact test), and forceps delivery (P = .002) increased the risk for sphincter damage. In multivariate regression models, only high birth weight (P = .004; odds ratio [OR] 1.68, 1.18-2.41, 95% confidence interval [CI]), and forceps delivery combined with mediolateral episiotomies (P < .001; OR 5.62, 2.16-14.62, 95% CI) proved to be independent risk factors. There was a statistical significant interaction of birth weight and head circumference (P = .012; OR 0.99, 0.98-0.99, 95% CI). Although the use of episiotomy conferred an increased risk toward a higher likelihood of severe perineal trauma, it did not reach statistical significance (P = .06; OR 2.15, 0.97-4.76, 95% CI). CONCLUSIONS: In consistence with previous reports, women who are vaginally delivered of a large infant are at a high risk for sphincter damage. Although the rate of these complications was surprisingly low in vaginally assisted childbirth, the use of forceps, even if routinely combined with mediolateral episiotomy, should be minimized whenever possible.     

Risk factors for third-degree perineal tears in vaginal delivery, with an analysis of episiotomy types

OBJECTIVE: To determine the risk factors for third-degree perineal tears during vaginal delivery and to investigate the relation between different types of episiotomy and the occurrence of such tears. STUDY DESIGN: This retrospective multicenter study consisted of an analysis of data from the delivery databases of the University Hospital of Vienna and Semmelweis Frauenklinic Wien between February and July 1999. The study was restricted to a sample that included all women with uncomplicated pregnancy as well as uncomplicated first and second stages of labor, gestational age > 37 weeks and a pregnancy with cephalic presentation. Women with multiple gestations, noncephalic presentation, cesarean deliveries, shoulder dystocia and gestational age < or = 37 weeks were excluded from the study. RESULTS: Among the 1,118 births, 37 women (3.3%) experienced third-degree perineal tears. The use of episiotomy per se and the type of episiotomy (midline) as well as forceps delivery, primiparity, large infant head diameter, prolonged second stage of labor and use of oxytocin were identified as risk factors for third-degree perineal tears during vaginal delivery. When analyzing different types of episiotomy, there was approximately a sixfold-higher risk of third-degree perineal tears in women undergoing midline episiotomy as compared to mediolateral episiotomy. A stepwise logistic regression analysis revealed that episiotomy, prolonged second stage of labor and large infant head diameter remained independent risk factors for third-degree perineal tears. CONCLUSION: We found several risk factors for third-degree perineal tears. The use of midline episiotomy was associated especially with an increased risk of severe anal sphincter tears. To prevent women from long-term sequelae due to third-degree perineal tears, avoidable risk factors should be minimized whenever possible.     

Episiotomy increases perineal laceration length in primiparous women

OBJECTIVE: The aim of this study was to determine the clinical factors that contribute to posterior perineal laceration length. STUDY DESIGN: A prospective observational study was performed in 80 consenting, mostly primiparous women with term pregnancies. Posterior perineal lacerations were measured immediately after delivery. Numerous maternal, fetal, and operator variables were evaluated against laceration length and degree of tear. Univariate and multivariate regression analyses were performed to evaluate laceration length and parametric clinical variables. Nonparametric clinical variables were evaluated against laceration length by the Mann-Whitney U test. RESULTS: A multivariate stepwise linear regression equation revealed that episiotomy adds nearly 3 cm to perineal lacerations. Tear length was highly associated with the degree of tear (R = 0.86, R(2) = 0.73) and the risk of recognized anal sphincter disruption. None of 35 patients without an episiotomy had a recognized anal sphincter disruption, but 6 of 27 patients with an episiotomy did (P <.001). Body mass index was the only maternal or fetal variable that showed even a slight correlation with laceration length (R = 0.30, P =.04). CONCLUSION: Episiotomy is the overriding determinant of perineal laceration length and recognized anal sphincter disruption.     

Severe perineal lacerations during vaginal delivery: the University of Miami experience

OBJECTIVE: After childbirth-related third- or fourth-degree perineal lacerations, the estimated incidence of wound disruption, fecal incontinence, or fistula ranges from 1% to 10%. Risk factors associated with severe laceration were analyzed at a single large teaching institution.Study Design: This study consisted of an analysis of data from the delivery database of Jackson Memorial Hospital, University of Miami, from 1989 through 1995. Included were vaginal deliveries for which complete information was available on maternal age, parity, ethnicity (white, black, or Hispanic), birth weight, episiotomy versus no episiotomy, type of episiotomy, and delivery (normal spontaneous, vacuum, or forceps). Multiple gestations, cases of shoulder dystocia, cesarean deliveries, patients with a history of cesarean delivery, and babies weighing <500 g at birth were excluded from this study. Both univariate and multivariate analyses were performed with variables such as maternal age, race, birth weight, type of episiotomy if any, and type of vaginal delivery. RESULTS: Among the 71,959 women who were delivered at our institution during the 7-year study period, 50,210 met the inclusion criteria. Through time there had been a decline in the use of episiotomy in general and of midline episiotomy in particular. The annual total number of deliveries also decreased. The episiotomy procedure per se and the type of episiotomy as well as birth weight, assisted vaginal delivery, and older maternal age were identified as independent risk factors associated with third- and fourth-degree perineal lacerations. CONCLUSION: Although episiotomy is an important risk factor for severe lacerations after vaginal delivery, there are other significant independent risk factors, such as maternal age, birth weight, and assisted vaginal delivery, that should be considered in counseling and making decisions regarding delivery modality. Older patients who are being delivered of a first child are at higher risk for severe laceration. Midline episiotomy and assisted vaginal delivery should therefore be avoided in this population whenever possible, especially in the presence of a large baby.     

Episiotomy and the risk of severe perineal injuries among Korean women*

Purpose: We examined the frequency of severe perineal injuries according to the use of episiotomy in vaginal deliveries of Korean women.

Materials and methods: This is a retrospective cohort study in which 358 consecutive parturients were included. Women were divided into episiotomy (n?=?115) and no episiotomy (n?=?243) groups. The main outcome was the occurrence of severe (third or fourth degree) perineal injuries. Delivery records and medical documents were reviewed to collect the data. Parametric and nonparametric tests were used as appropriate.

Results: There were no significant differences in the frequency of severe perineal injuries between two groups (6.1% (7/115) in episiotomy versus 3.7% (9/243) in no episiotomy group, p?=?0.308). Anterior perineal laceration was more frequent (40.3% (98/243) vs. 18.3% (21/115), p?Conclusions: There was no difference in the occurrence of severe perineal injuries according to the use of episiotomy.     

Does the angle of episiotomy affect the incidence of anal sphincter injury?

OBJECTIVE: Mediolateral episiotomy is associated with lower rates of significant perineal tears than midline episiotomy. However, the relationship between precise angle of episiotomy from the perineal midline and risk of third-degree tear has not been established. This study quantifies this relationship. DESIGN: Case-control study. SETTING: National Maternity Hospital, Dublin, Ireland. SAMPLE: One hundred primiparous women who had undergone right mediolateral episiotomy 3 months previously. METHODS: Two groups of primiparous women were compared. Cases had sustained clinically apparent anal sphincter injury during delivery, while controls had not. The angle of episiotomy measured from the midline was marked on a superimposed sheet of transparent plastic film and measured using a protractor. Data were analysed using Student's t test, chi-square test and logistic regression analysis. MAIN OUTCOME MEASURES: Angle of mediolateral episiotomy from the perineal midline. RESULTS: Fifty-four cases and 46 controls were assessed. Cases were more likely to have undergone assisted delivery and consequently to have been delivered by an obstetrician than by a midwife. The mean angle of episiotomy measured significantly smaller in cases (30 degrees, 95% CI 28-32 degrees) than in controls (38 degrees, 95% CI 35-41 degrees; P<0.001). Analysis showed a 50% relative reduction in risk of sustaining third-degree tear for every 6 degrees away from the perineal midline that an episiotomy was cut. CONCLUSIONS: These results show that a larger angle of episiotomy is associated with a lower risk of third-degree tear and mediolateral episiotomy incisions should be made at as large an angle as possible to minimise the risk of sphincter disruption.     

Incidence and risk factors for severe perineal laceration after vaginal delivery in Japanese patients

Objective: The aim of this study was to assess the frequency of severe perineal lacerations defined as either third- or fourth-degree lacerations during normal spontaneous vaginal delivery and to evaluate potential risk factors in Japanese patients. Materials and methods: An electronic audit of the perinatal database at the Tama-Nagayama Hospital of Nippon Medical School and Yamaguchi Hospital from 1997 through 2004 was completed. Singleton vaginal vertex deliveries were analyzed for potential risk factors using univariate and multivariate logistic regression analysis. Results: From the database, 7,946 deliveries were identified, with 135 deliveries resulting in severe lacerations (1.7%). In the multivariate logistic regression analysis, severe lacerations were associated significantly with primiparous (odds ratio, 4.36; 95% CI, 2.17–9.57), oxytocin use (odds ratio, 2.19; 95% CI, 1.27–3.73), midline episiotomy (odds ratio, 4.68; 95% CI, 2.09–11.55), forceps-assisted delivery (odds ratio, 7.11; 95% CI, 1.95–20.59), vacuum-assisted delivery (odds ratio, 5.93; 95% CI, 3.38–10.36), and shorter attendant experience (odds ratio, 2.88; 95% CI, 1.12–9.81). Conclusions: The present study demonstrated that operator factors, such as midline episiotomy, oxytocin use, assisted delivery and attendant experience, are independent risk for severe perineal lacerations after vaginal delivery in Japanese patients. The results suggest that midline episiotomy and assisted vaginal delivery, especially forceps-assisted delivery should be avoided in patients who are being delivered of a first child whenever possible.     

Risk Factors for Obstetric Anal Sphincter Injury: A Prospective Study

Abstract: Background: Anal incontinence is an embarrassing condition that is largely underreported. Obstetric anal sphincter injuries are the major etiological factor. Recognition of risk factors may minimize the development of sphincter injuries. The objective of this study was to identify risk factors for sphincter injuries and measure dimensions of mediolateral episiotomies. Methods: Women expecting their first vaginal delivery were invited to participate, and an experienced research fellow performed a perineal and rectal examination and classified tears according to the new international classification. Dimensions of episiotomies were measured and obstetric variables recorded prospectively. Results: Of the 241 women recruited, 59 (25%) sustained sphincter injuries. Univariate analysis revealed that forceps delivery OR 4.03 (1.63–9.92), vacuum extraction OR 2.64 (1.25–5.54), gestation > 40 weeks OR 3.18 (2.35–4.29), and mediolateral episiotomy OR 5.0 (2.64–9.44) were associated with these injuries. In addition, compared with women who had no injuries, sphincter injuries were more common with higher birthweight (3.51 vs 3.17 kg, p < 0.01), larger head circumference (34.3 vs 33.3 cm, p < 0.01), and longer second stage of labor (76 vs 51 min, p < 0.01). Multiple logistic regression revealed higher birthweight and mediolateral episiotomy OR 4.04 (1.71–9.56) as independent risk factors. Episiotomies angled closer to the midline were significantly associated with such injuries (26 vs 37 degrees, p = 0.01). No midwife and only 13 (22%) doctors performed truly mediolateral episiotomies. Conclusions: Mediolateral episiotomy is an independent risk factor for anal sphincter injuries. Although a liberal policy of mediolateral episiotomy does not appear to reduce the risk of such injuries, it may be related to inappropriate technique. A concerted approach to educate trainees in appropriate episiotomy technique and identification of sphincter injuries is imperative to enable reexamination of the true merits or disadvantages of mediolateral episiotomy. (BIRTH 33:2 June 2006)     

Trends in major modifiable risk factors for severe perineal trauma, 1996–2006

OBJECTIVE: To examine what effect the major modifiable risk factors for severe perineal trauma have had on the rates of this trauma over time. METHODS: A retrospective observational cohort study of singleton vaginal deliveries taken from a perinatal database for the period 1996 through 2006. RESULTS: A total of 46,239 singleton vertex vaginal deliveries met the inclusion criteria. Major risk factors for severe perineal trauma were increased maternal age (odds ratio [OR] 1.28, 95% confidence interval [CI] 1.1-1.5), non-African American ethnicity (OR 1.5, 95% CI 1.3-1.7), nulliparity (OR 4.8, 95% CI 4.11-5.6), fetal birth weight (OR 2.2, 95% CI 1.9-2.4), forceps (OR 8.3, 95% CI 5.4-10.8), vacuum (OR 2.9, 95% CI 1.9-4.4), and midline episiotomy (OR 5.7, 95% CI 5.0-6.4). Evaluation of the changes in rates of these factors over the study period revealed that the decline in the rates of episiotomy and the use of forceps accounted for a reduction in severe lacerations of more than 50%. CONCLUSION: Reduction of severe perineal trauma by restricted use of the 2 modifiable clinical variables, episiotomy and forceps, is evident over time.     

Hospital Variation in Episiotomy Use and the Risk of Perineal Trauma During Childbirth

Background: Episiotomies are the most frequently performed surgical procedure among United States women, but there are no published epidemiological studies of the extent of variation in episiotomy use among different obstetrical providers, or the outcomes associated with different levels of use. The objective of this study was to assess the extent of hospital variation in the use of episiotomy and the relationship between hospital episiotomy use and the incidence and risk of perineal trauma among women residing in a large urban area in the United States. Methods: Linked birth certificate and hospital discharge data pertaining to births to nulliparous women without prolonged labor or obstructed deliveries, and with infants weighing between 2500 and 4000 g, were analyzed for 18 major maternity hospitals. The relationship between episiotomy use and perineal trauma at the hospital level was examined using regression analysis. Results: Hospital episiotomy rates ranged from approximately 20 to 73 percent. The rate of third or fourth degree perineal lacerations varied from a low of 4 percent to a high of more than 13 percent among hospitals. Rates of episiotomy were significantly correlated with rates of a third or fourth degree perineal laceration (r = 0.70; p < 0.01), and with the hospital‐specific, adjusted odds ratios for such lacerations (r = 0.65; p < 0.01). Conclusions: Findings from the analysis of epidemiological data for this study population were consistent with those from clinical studies, indicating that liberal as opposed to restrictive use of episiotomy is unwarranted, and probably even harmful. Hospital episiotomy rates exceeded 20 percent in all cases, but such rates appear difficult to justify in face of the evidence. (BIRTH 29:2 June 2002)     

The effects of mediolateral episiotomy on pelvic floor function after vaginal delivery

OBJECTIVE: To evaluate the effect of mediolateral episiotomy on puerperal pelvic floor strength and dysfunction (urinary and anal incontinence, genital prolapse). METHODS: Five hundred nineteen primiparous women were enrolled 3 months after vaginal delivery. Puerperae were divided in 2 groups: group A (254 women) comprised the women who received mediolateral episiotomy and group B (265 women) the women with intact perineum and first- and second-degree spontaneous perineal lacerations. Each woman was questioned about urogynecological symptoms and examined by digital test, vaginal perineometry, and uroflowmetric stop test score. Data were subjected to Student t test and Fisher exact test to assess, respectively, the difference between the mean values and the proportions within the subpopulations. Using a simple logistic regression model to test an estimate of relative risk, we expressed the odds ratios of the variables considered with respect to the control population (group B). RESULTS: No significant difference was found with regard to the incidence of urinary and anal incontinence and genital prolapse, whereas dyspareunia and perineal pain were significantly higher in the episiotomy group (7.9% versus 3.4%, P =.026; 6.7% versus 2.3%, P =.014, respectively). Episiotomy was associated with significantly lower values, both in digital test (2.2 versus 2.6; P <.001) and in vaginal manometry (12.2 versus 13.8 cm water; P <.001), but not in uroflowmetric stop test. CONCLUSION: Mediolateral episiotomy does not protect against urinary and anal incontinence and genital prolapse and is associated with a lower pelvic floor muscle strength compared with spontaneous perineal lacerations and with more dyspareunia and perineal pain. LEVEL OF EVIDENCE: II-2     

Minimizing genital tract trauma and related pain following spontaneous vaginal birth

Genital tract trauma is common following vaginal childbirth, and perineal pain is a frequent symptom reported by new mothers. The following techniques and care measures are associated with lower rates of obstetric lacerations and related pain following spontaneous vaginal birth: antenatal perineal massage for nulliparous women, upright or lateral positions for birth, avoidance of Valsalva pushing, delayed pushing with epidural analgesia, avoidance of episiotomy, controlled delivery of the baby's head, use of Dexon (U.S. Surgical; Norwalk, CT) or Vicryl (Ethicon, Inc., Somerville, NJ) suture material, the "Fleming method" for suturing lacerations, and oral or rectal ibuprofen for perineal pain relief after delivery. Further research is warranted to determine the role of prenatal pelvic floor (Kegel) exercises, general exercise, and body mass index in reducing obstetric trauma, and also the role of pelvic floor and general exercise in pelvic floor recovery after childbirth.     

Episiotomy – risk factors and outcomes*

Objective: To identify risk factors for mediolateral episiotomy, and evaluate the risk of obstetrical anal sphincter injury (OASI) among women with an episiotomy.

Methods: A retrospective cohort study of all singletons vaginal deliveries at term between 2007 and 2014. Spontaneous and operative vaginal deliveries were compared separately, as well as nulliparous and multiparous women.

Results: Overall, 41,347 women were included in the spontaneous vaginal delivery group: 12,585 (30.4%) nulliparous and 28,762 (69.6%) multiparous women. Risk factors for episiotomy (nulliparous) were maternal age (aOR 0.98), gestational age (GA, aOR 1.07), regional analgesia (RA, aOR 1.18), labor induction (aOR 1.17), meconium (aOR 1.37) and birth weight (BW, aOR 1.04). Episiotomy was associated with PPH (aOR 1.49). Among multiparous, risk factors were maternal age (aOR 1.04), previous vaginal delivery (aOR 0.38), GA (aOR 1.06), RA (aOR 1.22), meconium (aOR 1.22) and BW (aOR 1.05). Episiotomy was associated with 3rd degree perineal tear (aOR 2.26, 95% CI 1.03-4.97). Only birth weight (nulliparous) and previous vaginal deliveries (multiparous) were contributors for episiotomy in the OVD group.

Conclusion: Several risk factors for mediolateral episiotomy exist. Episiotomy does not protect nulliparous women, and may be associated with an increased risk for multiparous, for OASI. Therefore, the practice of routine episiotomy should be abandoned, and the practice of selective episiotomy reconsidered.     

Asistencia obstétrica y trauma perineal

Objectives

In our center, the overall frequency of episiotomy has markedly decreased while the frequency of midline episiotomy has increased. The aims of the present study were two-fold: a) to determine whether restrictive episiotomy is associated with a lower frequency of perineal injury, and b) to identify perineal injury due to the predominant use of midline episiotomy.

Material and method

A total of 90,030 vaginal deliveries in the Hospital Universitario Materno Infantil de Canarias from January 1, 1992 to December 31, 2005 were studied. The frequency and type of episiotomy, the frequency of tears and their severity, and the association between type of episiotomy and the frequency and severity of perineal tears were analyzed. In addition, the same variables were studied in forceps deliveries. The chi-squared test was used and statistical significance was set at a probability value of less than 5%. When statistically significant differences were detected, odds ratios with 95% confidence intervals were calculated. The SPSS V.11 statistical package was used.

Results

The frequency of episiotomy decreased from 73.3% in 1992 to 38.2% in 2005. The frequency of mediolateral episiotomy decreased from 59.3% in 1992 to 18.2% in 2005 while that of midline episiotomy increased from 14% to 20%. The number of grade I and II tears increased while no significant changes in the frequency of grade III and IV tears were observed. The frequency of grade I and II tears was significantly higher when episiotomy was not performed. No statistically significant differences were found in the frequency of grade I and II tears between midline and mediolateral episiotomy or in the frequency of grade III and IV tears between these two procedures. In forceps deliveries, the frequency of tears, both grades I and II (49.5%) and grades III and IV (8.4%), was higher when episiotomy was not performed and significant differences were found in comparison with the frequency of tears in women with midline episiotomy (8.4% grade I or II tears and 4.2% grades III or IV) or mediolateral episiotomy (10.2% grade I or II tears and 4% grades III or IV tears). No differences were found in the frequency of grade III and IV tears between midline and mediolateral episiotomy.

Conclusions

a) A restrictive episiotomy policy should be followed in vaginal deliveries; b) midline episiotomy should be performed whenever, in the obstetrician’s opinion, the course of labor and expulsion and the perineal characteristics allow this procedure, since it does not increase the frequency of grade III-IV tears, and c) episiotomy should be performed more frequently in forceps deliveries, with a preference for midline episiotomy since, if correctly indicated, this procedure does not increase the frequency of grade III-IV tears.