TRENDS IN MAJOR RISK FACTORS FOR ANAL SPHINCTER LACERATIONS: A I 0-YEAR STUDY

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1 TRENDS IN MAJOR RISK FACTORS FOR ANAL SPHINCTER LACERATIONS: A I 0-YEAR STUDY N. L. McLeod, MD, FRCSC, I D. T. Gilmour, MD, FRCSC, 2 K. S. Joseph, MD, PhD, 3 S. A. Farrell, MD, FRCSC,4 E. R. Luther, MD, FRCSCs Department of Obstetrics and Gynaecology. Dalhousie University, Halifax NS 3Perinatal Epidemiology Research Unit: Department of Obstetrics and Gynaecology and Department of Pediatrics. Dalhousie University, Halifax NS Abstract Objectives: (I) To identify independent risk factors for anal sphincter laceration. (2) to determine the trend in rates of anal sphincter laceration over a 10-year period, and (3) to examine the impact of temporal trends in risk factors on anal sphincter laceration rates. Methods: Population-based data were obtained from the Nova Scotia Atlee Perinatal Database, on women who had a singleton vaginal live birth ~500 g for the years 1988 to Risk factors for anal sphincter laceration were identified using stepwise logistic regression. A multivariate model was used to study temporal changes in laceration rates after controlling for changes in parity, episiotomy rates. operative vaginal deliveries. birth weight. prolonged second stage of labour, and other determinants. Results: Nulliparity (relative risk [RR] :::: 6.97). occiput posterior position (RR :::: 2.44). non-vertex presentations (RR :::: 2.27), second stage ~ 120 min (RR range :::: ), delivery by an obstetrician (RR :::: 1.30), and birth weight ~3000 g (RR range :::: ) increased the risk of laceration. Instrument-assisted delivery involved risks that ranged from a 2-fold increase for a vacuum-assisted delivery (RR :::: 2.15) to a greater than 5-fold increase for a forceps delivery after an unsuccessful vacuum extraction (RR :::: 5.69). Episiotomy. particularly midline incisions. increased the risk of laceration (RR :::: 2.57). The risk of a sphincter lacera~ion increased 2-fold from 1988 to despite controlling for risk factors. Conclusions: Sufficient evidence exists about the risk factors for anal sphincter laceration to permit modification of management of labour and delivery to minimize the risk of anal sphincter laceration. Increased awareness of the clinical importance of recognition and repair of anal sphincter laceration may explain the rising incidence. Key Words Anal sphincter, laceration. risk factors, maternal and neonatal morbidity Competing interests: None declared. Received on August Revised and accepted on October Resume Objectifs : (I) Cerner les facteurs de risque independants de laceration du sphincter externe de I'anus; (2) determiner les tendances des taux de laceration du sphincter externe de I'anus sur une periode de loans; (3) examiner I'effet, sur les taux de laceration, de ces tendances temporelles quant aux facteurs de risque. Methodes : Des donnees stratifiees representatives ont ete recueillies aupres de la base de donnees perinatales ATLEE de la Nouvelle-Ecosse; elles portaient sur femmes ayant accouche d'un enfant unique et vivant de 500 g ou plus. par voie vaginale, de 1988 a On a identifie les facteurs de risque de laceration du sphincter externe de I'anus au moyen d'une analyse de regression sequentielle. Un modele a variables multiples a ete utilise pour etudier les changements temporels des taux de laceration apres avoir tenu compte des changements suivants : la parite, les taux d'episiotomie, les accouchements par voie vaginale avec chirurgie, Ie poids de naissance, un second stade du travail prolonge et certains aut res facteurs determinants. Resultats : Les facteurs suivants ont fait augmenter Ie risque de laceration: nulliparite (risque relatif [RR] :::: 6,97), presentation occipito-posterieure (RR :::: 2,44), presentations autres que du sommet (RR :::: 2.27), deuxieme stade ~ 120 min. (etendue du RR :::: de 1,47 a 2,02), accouchement en presence d'un obstetricien (RR :::: 1,30), poids de naissance 2: 3000 g (etendue du RR = de 1,43 a 6,63). Les accouchements OU I'utilisation d'instruments a ete necessaire comportaient des risques accrus allant du double, pour un accouchement par extraction sous vide (RR :::: 2,15), a plus du quintuple, pour un accouchement par application de forceps apres I'echec d'une extraction sous vide (RR = 5,69). L'episiotomie, surtout I'incision du plan median, a fait augmenter Ie risque de laceration (RR :::: 2.57). Le risque de laceration du sphincter externe a double de 1988 a 1997, et ce, en depit de la neutralisation de I'effet des facteurs de risque. Conclusions: Les donnees existantes sur les facteurs de risque de laceration du sphincter externe de I'anus sont suffisantes pour permettre la modification de la prise en charge du tra-. vail et de I'accouchement dans Ie but de minimiser Ie risque de laceration du sphincter externe de I'anus. 1/ se peut que I'augmentation graduelle de son incidence, que nous avons constatee, s'explique par une sensibilisation accrue a I'importance clinique de deceler et de reparer les lacerations du sphincter externe de I'anus. J Obstet Gynaecol Can 2003;25(7): JOGe JULY 2003

2 INTRODUCTION Obstetrical perineal trauma may lead to significant short- and long-term morbidities. 1 Clinically detected anal sphincter lacerations occur in 0.5% to 3.3% of vaginal deliveries. 1-7 Previous studies have identified nulliparity,3,5j-9 instrument-assisted vaginal delivery with either vacuum 10,11 or forceps,9,12-14 episiotomy,9,12-14 and increased birth weight3,5,6,9 as being significant risk factors for anal sphincter laceration. There have been limited or conflicting reports concerning other associated factors including epidural anaesthesia,5,7,9,10,12 duration of the second stage oflabour,7,15 and type of physician performing the delivery.12 These studies had small sample sizes5,7,12,16 and conflicting results concerning many of the risk factors. 5,12 The objectives of this study were to use the data from a large perinatal database to identify independent risk factors for anal sphincter laceration, determine the trend in rates of anal sphincter laceration over a 10-year period, and examine the impact of temporal trends in risk factors on anal sphincter laceration rates. METHODS We conducted a population-based retrospective cohort study over the 1 O-year period of 1988 to All singleton vaginal births resulting in a live neonate weighing ~500 g were included. Data were obtained from the Nova Scotia Arlee Perinatal Database, which contains information on maternal, labour and delivery, and neonatal characteristics for all births that occur in the province of Nova Scotia. Trained health-records personnel abstracted information from the database, and the data quality in the Nova Scotia Arlee Perinatal Database was assured by periodic data abstraction and validation studies to monitor data quality. 17 Third-degree lacerations were defined as those that extended partially or completely through the external anal sphincter. Fourth-degree lacerations were defined as those that extended through the rectal mucosa. Unless otherwise indicated, for this analysis, third- and fourth-degree lacerations were combined and referred to as anal sphincter laceration. For the purposes of this analysis, the criteria for fetal distress included one or more of: "fetal distress" documented in the chart by the attending physician; prolonged tachycardia, bradycardia, or fetal heart rate decelerations, which required interventions such as vacuum extraction or forceps delivery; and a scalp ph <7.2. The type of hospital was defined as: a tertiary care hospital, having obstetricians, pediatricians, and a level II neonatal intensive care unit (NICU); a regional hospital, having obstetricians and pediatricians, but no level II NICU; and a community hospital, having no obstetricians, pediatricians, or NICU. The second stage of labour was defined as the time from full cervical dilatation to delivery. Temporal trends in vaginal parity, episiotomy, spontaneous and operative vaginal deliveries, birth weight, and prolonged second stage were determined for the 10-year period. A single stepwise logistic regression was used to quantify the increased risk associated with individual factors while controlling for confounding variables. Relative risk (RR) and 95% confidence intervals (CI) were calculated, and a Pvalue of <0.05 was considered statistically significant. A multivariate model was used to examine temporal trends in anal sphincter laceration rates, after controlling for changes in relevant determinants. RESULTS During the 10-year study period, of the women in Nova Scotia who had a vaginal delivery of a liveborn singleton infant weighing ~500 g, 3244 (3.6%) were foufld to have an anal sphincter laceration. Women received episiotomies during 47.5% of the deliveries. Eighty-five percent of episiotomies were mediolateral incisions (n = 36792) and 15% (n = 6534) were midline. The maternal risk factors associated with anal sphincter laceration are presented in Table 1. Having no previous vaginal birth was the greatest risk of anal sphincter laceration (RR = 6.97, 95% CI = ). A prepregnancy maternal weight of <50 kg was associated with an increased risk oflaceration relative to a prepregnancy weight of 50 kg to 59 kg (RR = 1.34, 95% CI = ). Protective against anal sphincter laceration were both maternal age <25 years and a prepregnancy weight of ~60 kg, relative to maternal age of 25 to 29 years and a prepregnancy weight of 50 kg to 59 kg. The results of the analysis oflabour factors and risk of anal sphincter laceration are shown in Table 2. While a second stage duration ofless than 20 minutes was protective, a second stage of 120 minutes or longer was associated with an increased risk of sphincter laceration relative to a second-stage duration of 20 to 39 minutes. The risk increased for each hour beyond 2 houts. Fetal malposition at delivery and non-vertex presentation were each associated with a 2-fold increased risk oflaceration. Delivery by an obstetrician compared with delivery by a general practitioner (RR = 1.30, 95% CI = ) and the presence of fetal distress at the time of delivery (RR = 1.36,95% CI = ) both increased the risk of anal sphincter laceration. The use of epidural or spinal anaesthesia had a small protective effect. Table 3 illustrates delivery risk factors associated with anal sphincter laceration. All types of instrument-assisted vaginal delivery were associated with an increased risk of anal sphincter laceration compared to spontaneous vaginal delivery. Vacuum-assisted vaginal delivery was associated with a 2-fold increased risk (RR = 2.15, 95% CI = ). Forceps rotation also increased the risk (RR = 1.38,95% CI = ). With forceps-assisted vaginal deliveries, the risk increased with higher station at delivery (low forceps: RR = 3.53, 95% CI = ; mid-forceps: RR = 4.46, 95% CI = ). The highest risk of anal sphincter laceration from instrument-assisted vaginal deliveries was found for a forceps delivery following an unsuccessful JOGC JULY 2003

3 attempt at vacuum extraction (RR= 5.69, 95% CI = ). Episiotomy increased the risk, with midline incisions having more than twice the risk (RR = 2.57, 95% CI = ) of mediolateral incisions (RR = 1.14, 95% CI = ). Delivery in a tertiary-care hospital increased the risk of anal sphincter laceration (RR = 1.19,95% CI = ), when compared to a community hospital. Newborn risk factors are shown in Table 4. The risk of anal sphincter laceration increased progressively with increasing birth weight. Although delivery from 38 to 40 weeks was associated with increased risk of sphincter laceration relative to delivery at 37 weeks (38 weeks: RR = 1.48,95% CI = ; 39 weeks: RR = 1.43,95% CI 0= ; 40 weeks: RR 0= 1.35, 95% CI = ), delivery beyond 41 weeks' gestation was not associated with an increased risk. The temporal trend in anal sphincter laceration for the 1 O-year period is shown in Figure 1. Temporal trends in operative vaginal delivery, episiotomy, birth weight ;:::3000 g, and prolonged second stage are depicted in Figure 2. We observed an increase in the anal sphincter laceration rate from 2.8% (95% CI 0= ) in 1988 to 3.6% (95% CI = ) in 1997 (Pvalue for trend <0.001). This increase in laceration rates was confined to an increase in third-degree lacerations only; which increased from 2.1 % in 1988 to 3.1 % in The increase in laceration rates occurred despite a decrease in episiotomy rates from 66.7% (95% CI = ) in 1988 to 28.0% (95% CI = ) in 1997 (Pvalue for trend <0.001). The overall rate of instrument-assisted vaginal deliveries decreased over the 10-year study period. While the rate of forceps deliveries as a percentage of all vaginal deliveries decreased from 16.3% to 8.2%, vacuum-assisted deliveries increased from 0.3% to 4.6%. The proportion of singleton live births weighing ;:::3000 g increased from 82.8% to 83.4% over the 10-year study period. The percentage of women with a second stage longer than 2 hours increased over the study interval, from 11.3% in 1988 to 16.4% for vaginal deliveries of singletons in The proportion of women having had no previous vaginal birth did not change during the study period. After controlling for changes in all risk factors, we observed a 2-fold increase in anal sphincter laceration rates between 1988 and 1997 (P <0.001). DISCUSSION The large Nova Scotia Arlee Perinatal Database and the span of 10 years allowed a comprehensive evaluation of risk factors for anal sphincter laceration. The susceptibility to laceration in women undergoing their first vaginal delivery3,5,7-9 may be modifiable by massage,18 and is possibly due to differences in TABLE I MATERNAL RISK FACTORS ASSOCIATED WITH ANAL SPHINCTER LACERATION*t Risk Factor Crude RR (95% CI) Adjusted RR (95% CI) PValue Vaginal parity ( ) 6.97 ( ) <0.001 I 2.48 ( ) 2.23 ( ) < :: ( ) 0.47 ( ) 0.02 Maternal age (y) < ( ) 0.60 ( ) < ( ) 0.76 ( ) < ( ) ( ) ( ) 0.91 ( ) :: ( ) 0.84 ( ) 0.56 Prepregnancy weight (kg) < ( ) 1.34 ( ) < ( I) 0.89 ( ) ( ) 0.86 ( ) :: ( ) 0.75 ( ) <0.001 RR: relative risk; CI: confidence interval. 'Singleton vaginal delivery of liveborn 2::500 g. tanal sphincter lacerations included third- and fourth-degree lacerations. :J:Vaginal parity is defined as the number of prior vaginal deliveries. JOGC 2003

4 the elasticity and strength of connective tissue in the perineum. In our study population, all types of instrument-assisted vaginal delivery increased the risk of anal sphincter laceration compared to spontaneous vaginal delivery. Some authors 18 believe the placement of forceps on the fetal head, presumably increasing the presenting cranial diameter, predisposes to increased risk of perineal trauma when compared to vacuum delivery. Overall, there was a decrease in the number of instrument-assisted vaginal deliveries over the 10-year study period. While the rate of forceps delivery declined from 16.3% of all vaginal deliveries in 1988 to 8.2% in 1997, the rate of vacuum-assisted delivery increased 15-fold from 0.3% to 4.6% over the same time period. In this study, vacuum-assisted delivery carried approximately one-half the risk of anal sphincter laceration associated with mid-forceps delivery. The rate of episiotomy declined from 66.7% in 1988 to 28% in Previous work has demonstrated that episiotomy is highly associated with third- and fourth-degree obstetrical lacerations. 9,11-14 It should be anticipated that a significant decline in laceration rate would accompany such a change in episiotomy practice, yet this was not observed. Furthermore, 85% of the episiotomies in our study were by mediolateral incisions, and although our study and others 15,18 have demonstrated a risk oflaceration even with mediolateral incisions, this technique carries a lower risk than midline episiotomy. In this study, the risk of laceration increased progressively with increasing birth weight, in accordance with several previous studies. 3,5,6,9 With increasing fetal size, there is increasing risk of trauma to the mother. Ultrasound estimation of fetal weight may be helpful in counselling women about the route of delivery for macrosomic infants. In our study, increasing duration of the second stage of labour increased the rate of anal sphincter lacerations in our study population after the first 2 hours and there was a progressive TABLE 2 LABOUR RISK FACTORS ASSOCIATED WITH ANAL SPHINCTER LACERATION*t Risk Factor Crude RR (95% CI) Adjusted RR (95% CI) PValue Duration second stage (min) < ( ) 0.62 ( ) I ( ) 0.88 ( ) ( ) 1.09 ( ) ( ) 1.06 ( ) ( ) 1.47 ( ) < ( ) 1.79 ( ) < ( ) 2.02 ( ) <0.001 Position Occiput anterior Occiput posterior 3.30 ( ) 2.44 ( ) <0.001 Non-vertex 0.88 (Q ) 2.27 ( ) Type of physician General practitioner Obstetrician 3.10 ( ) 1.30 ( ) <0.001 Fetal distress No Yes 3.06 ( ) 1.36 ( ) <0.001 Labour augmentation No Yes 2.05 ( ) 0.91 ( ) 0.06 Epidural No Yes 3.28 ( ) 0.89 ( ) 0.03 RR: relative risk; CI: confidence interval. 'Singleton vaginal delivery of liveborn 2500 g. tanal sphincter laceration includes third- and fourth-degree lacerations. JOGC JULY 2003

5 TABLE 3 DELIVERY RISK FACTORS ASSOCIATED WITH ANAL SPHINCTER LACERATION*t Risk Factor Crude RR (95% CI) Adjusted RR (95% CI) PValue Rotation No rotation Manual 3.88 ( ) 0.95 ( ) 0.64 Forceps 8.60 ( ) 1.38 (1.12-1,48) <0.001 Method of delivery Spontaneous Vacuum 5.11 ( ) 2.15 (I ) <0.001 Outlet forceps 8.62 ( ) 3.62 ( ) <0.001 Low mid-forceps 9.68 ( ) 3.53 ( ) <0.001 Mid-forceps ( ) 4.46 ( ) <0.001 Forceps after vacuum ( ) 5.69 ( I) <0.001 Episiotomy None Mediolateral 4.15 ( ) 1.14 ( ) 0.03 Midline 6.38 ( ) 2.57 ( ) <0.001 Type of hospital Community Regional 1.19 ( ) 0.89 ( ) 0.21 Tertiary 1.86 ( I) 1.19 ( ) 0.04 RR: relative risk; CI: confidence interval. 'Singleton vaginal delivery of liveborn ;::500 g. tanal sphincter laceration includes third- and fourth-degree lacerations. TABLE 4 NEWBORN RISK FACTORS ASSOCIATED WITH ANAL SPHINCTER LACERATION*t Risk Factor Crude RR (95% CI) Adjusted RR (95% CI) PValue Birth weight (g) < ( ) 0.52 ( ) ( ) 0.84 ( ) ( ) 1.43 ( ) < ( ) 2.00 ( ) < ( ) 2.95 ( ) < ( ) 3.51 ( ) <0.001 ;:: ( ) 6.63 ( ) <0.001 Gestational age (wk) < ( ) 0.88 ( ) ,47 ( ) 1,48 ( ) ( ) 1.43 ( ) ( ) 1.35 ( ) ( ) 1.30 ( ) ( ) 1.31 ( ) 0.07 ;:: ( ) 0.89 (0.54-1,46) 0.64 RR: relative risk; Ci: confidence interval. 'Singleton vaginal delivery of liveborn 2':500 g. tanal sphincter laceration includes third- and fourth-degree lacerations. JOGe JULY 2003

6 ... c:: II) u l- II) a ~ ~ Year ---- Anal sphincter laceration rate Figure I. Temporal trends in anal sphincter laceration rates ~ c:: II) u l- II) 50 a r ~----~~==~ 20 +~ _ ~~I 10~::~jl====~====='-~==~~::::=~,t::::!:===~-::::::::-:::::r o Year -+-- Birth weight> 3000 g Second stage> 120 min Episiotomy ~Forceps ~Vacuum Figure 2. Temporal trends in risk factors for anal sphincter lacerations. JOGe JULY 2003

7 increase in risk with every hour beyond 2 hours in the second stage. Other investigators 1 5 have not found duration of the second stage to be related to anal sphincter laceration, but some authors 7 have suggested a protective effect of maternal pushing for less than 30 minutes. Over the 10-year study period, the number of women who experienced a second stage longer than 2 hours increased from 11.3% in 1988 to 16.4% in Delivery by an obstetrician increased the risk of anal sphincter laceration. Since information on trainee supervision was not available within our data source, we could not ascertain whether this increased risk associated with obstetricians was due to the confounding effect of trainees. However, Combs et al 12 found no significant difference in third- or fourth-degree lacerations at instrument-assisted vaginal delivery, when delivery by residents was compared to delivery by faculty. In this large population of women, although the overall incidence of anal sphincter laceration was consistent with other reports in the literature,i-7 the incidence increased over the 10-year study period despite decreasing rates of episiotomy and instrument-assisted vaginal delivery, and constant rates of first vaginal delivery and birth weight ~3000 g. There was an increase in the rate of women experiencing a second stage longer than 2 hours. The multivariate model used in our analysis allowed us to control for these confounders, while examining the change in risk of anal sphincter laceration. Our observed 2-fold increase in the risk of sustaining an anal sphincter laceration over the study period (RR = 1.94,95% CI = ), was not explained by changes in duration oflabour or rates of any of the recognized risk factors. Other unrecognized factors or practices may therefore be important determinants of risk. Recognition of the importance of avoiding perineal trauma has grown over the last decade l4,19 and a clinical trial has assessed strategies to minimize this trauma. 20 Increased awareness among physicians of the potential implications of vaginal birth for urinary and anal incontinence, pelvic floor function, and perineal pain has prompted questions about the wisdom of attempting vaginal delivery when severe perineal or pelvic floor trauma is likely to occur,4,21,22 and probably a higher rate of recognition of perineal injury at the time of delivery. This phenomenon may have resulted in the higher rate of sphincter lacerations found in our study. The fact that the increase in anal sphincter laceration rates appears to be restricted to third-degree tears would tend to support this hypothesis. Requests by women for elective Caesarean delivery to protect the pelvic floor are increasing and greater numbers of physicians are complying with these requests. 23 While the risk factors identified in our study do not explain the increased rate of anal sphincter laceration observed over the study period, they do provide guidance to physicians and midwives. Prevention of sphincter lacerations and their subsequent morbidities requires the delivery attendant to identify the woman at risk, and modify management to optimize the birth outcome. Parity and birth weight are non-modifiable factors. Intervention may alter the duration of the second stage, and the use of episiotomy and instrument-assisted delivery are choices. Our data support the recommendation that episiotomy should be avoided whenever possible, and when absolutely necessary, a mediolateral technique should be used. Manual rotation (if required), careful selection of instrument for operative vaginal delivery, and optimal management of the second stage of labour may reduce the risk of anal sphincter laceration. Women with multiple risk factors for anal sphincter laceration should be counselled regarding the implications of such an injury, as well as the potential benefits and risks of choosing Caesarean delivery as an alternative. REFERENCES I. Sultan AH. Anal incontinence after childbirth [review]. Curr Opin Obstet Gynecol 1997;9:32H. 2. Haadem K, Ohrlander S, Lingman G. Long term ailments due to anal sphincter rupture caused by delivery: a hidden problem. Eur J Obstet Gynecol Reprod Bioi 1988;27: Sultan AH, Kamm MA, Hudson CN, Bartram CI. Third degree obstetric anal sphincter tears: risk factors and outcome of primary repair. BMJ 1994;308(6933): Tetzschner 1; Sorensen M, Lose G, Christiansen J. Anal and urinary incontinence in women with obstetric anal sphincter rupture. Br J Obstet Gynaecol 1996; I 03( I 0): I S. Poen AC, Felt-Bersma RJF, Dekker GA, Deville W, Cuesta MA, Muewissen SGM. Third degree obstetric perineal tears: risk factors and the preventive role of mediolateral episiotomy. Br J Obstet Gynaecol 1997; I 04(5):563~. 6. Buekens P. Lagasse R, Dramaix M,Woliast E. Episiotomy and third degree tears. Br J Obstet Gynaecol 1985;92: Samuelsson E, Ladfors L,Wennerholm UB, Gareberg B, Nyberg K, Hagberg H. Anal sphincter tears: prospective study of obstetric risk factors. Br J Obstet Gynaecol 2000; I 07: Sorensen M,TetzschnerTT. Rasmussen 00, Bjarnsen J, Christiansen J. Sphincter rupture in childbirth. Br J Surg 1993;80: Zetterstrom J, Lopez A, Anzen B, Norman M, Holmstrom B, Mellgren A. Anal sphincter tears at vaginal delivery: risk factors and clinical outcome of primary repair. Obstet Gynecol 1999;94:21~. 10. Robinson IN, Norwitz ER, Cohen AP. McElrath TF, Liberman ES. Epidural analgesia and third or fourth degree lacerations in nulliparas. Obstet Gynecol 1999;94: I I. Ezenagu LC, Kakarua R, Bofill JA. Sequential use of instruments at operative vaginal delivery: is it safe? Am J Obstet Gynecol 1999; 180: Combs CA, Robertson PA, Laros RK Jr. Risk factors for third-degree and fourth-degree perineal laceration in forceps and vacuum deliveries. Am J Obstet Gynecol 1990; 163( I Pt I): I OH. 13. Labrecque M, Baillargeon L, Dallaire M, Tremblay A, Pinault Jj, Gingras S. Association between median episiotomy and severe perineal lacerations in primiparous women. Can Med Assoc J 1997; 156:797~ Klein MC, Gauthier RJ, Robbins JM, Kaczorowski J,Jorgensen SH, Franco ED, et al. Relationship of episiotomy to perineal trauma and morbidity, sexual dysfunction, and pelvic floor relaxation. Am J Obstet Gynecol 1994; 171 : Bek K, Laurberg S. Intervention during labor: risk factors associated with complete tear of the anal sphincter. Acta Obstet Gynecol Scand 1992;71 :52H. 16. Haadem K, Dahlstrom JA, Ling L, Ohrlander S. Anal sphincter function after delivery rupture. Obstet Gynecol 1987;70:53~. JOGC JULY 2003

8 17. Dodds LA, Smith L. Nova Scotia Atlee Perinatal Database: chart review. Halifax (NS): Reproductive Care Program of Nova Scotia; Eason E, Labrecque M, Wells G, Feldman P. Preventing perineal trauma during childbirth: a systematic review. Obstet Gynecol 2000;95: Logue M. Putting research into practice: perineal management during delivery. In: Robinson S, Thomson AM, editors. Midwives, research and childbirth. 2nd ed. London: Chapman and Hall; p House MJ, Cario G,Jones MH. Episiotomy and the perineum: a random controlled trial. J Obstet Gynecol 1986;7: I 07-1 O. 21. Farrell SA, Allen VM, Baskett TF. Parturition and urinary incontinence in primiparous women. Obstet Gynecol 200 I ;97: Farrell SA, Allen VM, Baskett TF. Anal incontinence in priparas. J Soc Obstet Gynaecol Can 200 I ;23: Sultan AH, Stanton SL. Preserving the pelvic floor and perineum during childbirth-elective Caesarean section? Br J Obstet Gynaecol 1996;103: The Use of Fetal Doppler in Obstetrics Programmes in 2003 Ma;llu1lallCt! of Certificatiotl Program of th Royal o//' of Physicilms and urgeon,s of,uuja. UpCOMING progbammes Toronto Sep mber Vantouv r <ktobef 24 & 25 Toronto 0\1 mber 14 & 15 Don't miss thi valuable self-directed learning module on The Use of F tal Doppler in Obstetrics. Supported by an un tricted u donaj grant from For mont orma ow qc.org or CX)II Ihe SOGC at (613) ext 248 JOGe