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LITERATURE REVIEW
Specific obstetrical risk factors for urinary versus anal incontinence 4 years after first delivery 夽
Facteurs de risque obstétricaux spécifiques de l’incontinence urinaire ou de l’incontinence anale quatre ans après le premier accouchement
X. Fritel
a,∗, B. Khoshnood
b, A. Fauconnier
caPoitiersUniversityHospital,InsermCIC0802,86000Poitiers,France
bInserm,UMRS953,Paris-6University,Epidemiologicalresearchunitonperinatalhealthand women’sandchildren’shealth,HôpitalCochin,75014Paris,France
cVersailles-St-QuentinUniversity,EA7285Riskandsafetyinclinicalmedicineforwomenand perinatalhealth,CHIPoissy-Saint-Germain-en-Laye,78000Poissy,France
Received6May2013;accepted17June2013
KEYWORDS
Urinaryincontinence;
Analincontinence;
Delivery
Summary
Aim.—Deliverycanbecomplicatedbyurinaryoranalincontinence(UIorAI).Wehypothesized thatthemechanismsofinjurymaydifferforUIandAI.Hence,obstetricalriskfactorsmaybe specificfordifferenttypesofincontinence.
Design.—Dataonmaternalcharacteristicswerecollectedatfirstdelivery.Dataonincontinence wereobtainedbyaquestionnairecompletedby627women4yearsafterfirstdelivery.UIwas definedby‘‘Doyouhaveinvoluntarylossofurine’’andAIby‘‘Doyouhaveinvoluntarylossof flatusorstool’’.Amultinomiallogisticregressionanalysiswasconductedtoassessriskfactors forUIonly,AIonly,andUI+AI.
Results.—Twenty-twopercentofwomenreportedUIonly,6.5%AIonly,and6.5%both.Risk factorsassociatedwithUIonlywereage(atfirstdelivery)≥30(OR2.27[95%CI1.47—3.49]), pre-existingUI(6.44[2.19—19.0])andpregnancyUI(3.64[2.25—5.91]).Riskfactorsassociated withAIonlywerelengthofthesecondactivestage>20minutes(2.86[1.15—7.13])andthird degree perineal tear(20.9 [1.73—252]). Significantpredictors ofUI+AI were age≥30 (2.65 [1.29—5.46]),noepidural(4.29[1.65—11.1]),thirddegreeperinealtear(20.0[1.28—314]),and UIbeforepregnancy(32.9[9.00—120]).Cesareandeliverywasnotsignificantlyassociatedwith
夽 Levelofevidence:3.
∗Correspondingauthor.
E-mailaddress:xavier.fritel@univ-poitiers.fr(X.Fritel).
1166-7087/$—seefrontmatter©2013ElsevierMassonSAS.Allrightsreserved.
http://dx.doi.org/10.1016/j.purol.2013.06.009
UI,AI,orUI+AI,althoughforallthreeoutcomes,theadjustedoddsratiosweresubstantially lessthanone.
Conclusion.—Wefoundspecificassociationsbetweenobstetricalriskfactorsandurinaryversus analincontinence4yearsafterfirstdelivery.Ourresultsareconsistentwiththehypothesisthat theunderlyingmechanismsofinjurydifferforUIandAI.
©2013ElsevierMassonSAS.Allrightsreserved.
MOTSCLÉS Incontinence urinaire;
Incontinenceanale; Accouchement
Résumé
Objectif.—L’accouchement peutse compliquer parune incontinence urinaireou anale(IU ou IA). Notre hypothèse est que si les mécanismes lésionnels sont différents pour chaque incontinence,les facteurs de risqueobstétricaux devraient être spécifiques à chaquetype d’incontinence.
Méthodes.—Les donnéessur la mère ontété recueilliesàla première naissance.Les don- néessurl’incontinenceontétéobtenuesparunquestionnaireremplipar627femmes,quatre ansaprèslepremieraccouchement.L’IUétaitdéfiniepar«Avez-vousdesfuitesinvolontaires d’urine?»etl’IApar«Avez-vousdespertesinvolontairesdegazoudeselles?».Unerégression logistiquemultinomialeaétéconduiteafind’estimerlesfacteursderisquepourl’IUisolée, l’IAisolée,etIU+IA.
Résultats.—Vingt-deux pourcent desfemmesavaientuneIUisolée,6,5%uneIAisolée,et 6,5%lesdeuxàlafois.Lesfacteursderisqueassociésàl’IUisoléeétaientunâge(aupremier accouchement) supérieur ou égal à 30ans (OR 2,27 [IC 95% 1,47—3,49]), une IU préexis- tante(6,44[2,19—19,0]),etuneIUdelagrossesse(3,64[2,25—5,91]).Lesfacteursderisque associésàl’IA isoléeétaientune duréedesefforts expulsifssupérieuresà20minutes(2,86 [1,15—7,13])et un périnée complet (20,0 [1,28—314]). Les facteurs de risques pour IU+IA étaientunâgesupérieur ouégalà30ans(2,65 [1,29—5,46]),l’absence depéridurale(4,29 [1,65—11,1]), unpérinée complet (20,0 [1,28—314]),et une IUpréexistanteà la grossesse (32,9[9,00—120]).L’accouchementparcésariennen’étaitpassignificativementassociéeàl’IU isolée,àIAisolée,ouIU+IA,bienquepourlestrois,lesORajustésétaientsensiblementinférieur àun.
Conclusion.—Nousavonstrouvédesassociationsspécifiquesentredesfacteursobstétricauxet l’incontinenceurinaireouanalequatreansaprèslepremieraccouchement.Nosrésultatssont compatiblesavecl’hypothèsequelesmécanismeslésionnelsdiffèrentpourl’IUetl’IA.
©2013ElsevierMassonSAS.Tousdroitsréservés.
Introduction
First childbirth may become complicated by urinary or anal incontinence (UI or AI). The exact pathophysiology ofpostnatal incontinence is notwell understood. Observ- ablelesionssuchasthirddegreeperinealtearscanexplain AI but this occurs in only a minority of deliveries. Other occult injury to the pelvic floor, e.g., pudendal neurop- athyorlevatoranimuscleavulsioncouldaffecturinaryor analcontinence[1].Thepudendalnerveinnervatesstriated musclesof thepelvic floor,includinglevatorani,urethral sphincterandanalsphincter.Riskfactorsforpudendalnerve damageduringchildbirtharebirthweight>4kgandasec- ondactivestagelongerthan30minutes[2].Thelevatorani muscle,which is involved in the maintenance of the uri- naryandanalcontinence, canalsobeinjuredat thetime ofchildbirth.UsingMRIfindings,DeLanceyreportedinjuries ofthelevatorani in20% ofprimiparous womenandDietz foundlesionsin36%ofwomenusingsonography[3,4].Risk factorsfor thelesionsof thelevator aniduring childbirth areadvancedmaternalage,forcepsdeliveryandthedura- tionofthe secondstage [5].The twosphincteric (urinary andanal)complexes arealsoboundbycrossedreflexlike thevesico-analreflex[6].
Previous literature has not elucidated to what extent postnatal UIandpostnatal AIresultfromthesameunder- lying mechanisms of injury. The analysis of risk factors associated with postnatal incontinence suggests that cer- tainriskfactorssuchasadvancedmaternalageandparity may be common to both UI and AI [7,8]. Other risk fac- tors may be more specifically associated with one type of incontinence. For example, UI during pregnancy has been found to be a specific risk factor for postnatal UI and instrumental vaginal childbirth for postnatal AI [9,10].
Wehypothesizedthatpregnancyanddelivery-associated traumatic mechanisms at the origin of postnatal incon- tinence differ at least to some extent for UI and AI.
Therefore, specific obstetrical risk factors are likely to be associated with different types of incontinence. The analysis of risk factors related to stress UI was pub- lished previously for a portion of the population [11].
To complete this objective, we performed a secondary analysis in the whole sample of primiparous to identify both risk factors that may be common to UI and AI, and those that may be specifically associated with different typesofpostnatal incontinence,4yearsafterafirstdeliv- ery.
Materials and methods
Ourdatawereinitiallycollectedforastudyaimedatcom- paring the risk of incontinence for women delivering in two maternity units [12]. One maternity had a policy of systematic episiotomy and the other a restrictive policy for episiotomy. The study population include nulliparous womenwhodeliveredalive-bornsingletonat37—41weeks in cephalic presentation in 1996. Mothers whose current mailingaddresswasnotknown(andthosedeceased)were excluded. Data on maternal characteristics (age, height, weight),pregnancy(gestationalage,epidural,secondactive stageduration,deliverymode,newborns’birthweight)were collected at the time of childbirth. Women were asked to provide information about pelvic floor disorders using apostalquestionnaire,which wassent 4yearsafterchild- birth.Intheabsenceofresponsetothefirstmail,asecond andif necessary athird mail wassent.The questionnaire collecteddataaboutprofessionandeducationlevelofthe mother,interventions onthe pelvicfloor sincechildbirth, newpregnanciesandpelvicfloorsymptoms.UIwasdefined byapositiveresponse(Yes)tothequestion ‘‘Doyouhave involuntarylossofurine?’’andAIwasdefinedbytheanswer
‘‘Yes’’to‘‘Doyouhaveinvoluntarylossofflatusorstool?’’
ThetypeofUIwasdefinedusingavalidatedquestionnaire (Bristol Female Lower Urinary Tract Symptoms question- naire), [13] severity of UI was measured with Sandvik’s score,[14]andAIwasassessedusingPescatori’sscore,[15]
as detailed in a previous publication [12]. The complete questionnaire used for the study is available online. The choiceof cutoffvaluesforcontinuous variables(maternal age<30,BMI<25kg/m2,gestational age<40weeks,active second stagelength>20minutes,newbornweight<4000g) wasdoneapriori.Wefoundnoevidenceofadifferencein theriskofUI4yearsafterfirstchildbirthforwomendeliv- eringinthetwomaternityunits.However,theriskofAIwas slightly higherfor womenwho deliveredin thematernity withapolicyofsystematicepisiotomy[12].Usingdatafrom thisenquiry,wefirstexaminedriskfactorsassociatedwith eachtypeofincontinence(UIorAI)usingtwoseparatelogis- ticregressionmodelsadjustedonmaternity.Allsignificant riskfactorsforUIorAIwerethenincludedinamultinomial logitanalysistoassess specificrisk factorsfor thefollow- ingoutcomes:UIonly,AIonly,andUI+AI.Variablesformode of delivery,third degree perinealtearand maternity unit were forced in the model irrespective of their statistical significanceinthelogisticmodels.Weusedestimatesofthe oddsratios in the multinomial model for each risk factor andoutcomeinordertoexaminetheextenttowhichspe- cificriskfactorsmaybeassociatedwithdifferenttypesof incontinence.
We complied with French laws ondata confidentiality, andrestrictionsontypeofdatacollected(e.g.noreligious or racial data). Informed consent was obtained from all studyparticipants.
Results
Among the 1323 primiparous women who met inclusion criteria, postal address wasno longervalid for 548 (41%) and one had died, 774 (59%) women received the postal
questionnaireand627 (81%)completed it.The firstdeliv- erywasspontaneousvaginalin368 cases,instrumentalin 209cases (95 by vacuum)and by cesarean section for 50 women.Continencedisorders4yearsafterfirstchildbirthof the627womenwhorespondedaresummarizedinTable1.
Theprevalence ofUI was29%(n=181)andthat ofAI13%
(82),22%ofwomen(140)reportedUIonly,6.5%(41)AIonly, and6.5%(41)bothUIandAI.
Risk factors for UI (with or without AI) were maternal age≥30atfirstdelivery(adjustedOR,2.3[95%CI1.5—3.4]), UIbeforefirstpregnancy (10.2[3.7—28.1]),andUI during firstpregnancy(3.3[2.1—5.1]).RiskfactorsforAI(withor without UI) were UI before first pregnancy (adjusted OR 5.2[95%CI2.3—11.8]),noepidural(versusyes)duringfirst delivery (2.4[1.2—4.8]), second activestage>20min (2.5 [1.2—5.1]), and occurrence of third degree perineal tear duringfirstdelivery(13.3[2.1—83.0]).Otherfactorstested andnon-significantwere:educationlevel,aBMIgreaterthan 25kg/m2,gestationalageat firstdelivery,afirstnewborn over4000g,pelvicfloorexercisesafterfirstdelivery,epis- iotomy at first delivery, a second delivery (this concerns 381 women), and an ongoing pregnancy (supplementary material,seeonlineadditionalTablesS1andS2).
Table2 presentstheresults ofthe multinomiallogistic regressionanalysistoassessspecificriskfactorsassociated withUI only, AIonly, and UI+AI.Estimates suggested that differentrisk factorswere associatedwith thethreeout- comes.RiskfactorsassociatedwithUIonlywerematernal ageatdelivery≥30(adjustedOR2.3[95%CI1.5—3.5]),pre- existingUI (6.4 [2.2—19.0]) and UI during pregnancy (3.6 [2.2—5.9]),whereasriskfactorsforAIonlyweredurationof thesecondactivestage>20min(2.9[1.1—7.1]),andthird degreeperinealtear(20.9[1.7—252]).Riskfactorssignifi- cantlyassociated with UI+AI were maternal age>30years (2.6[1.3—5.5]),UI beforepregnancy(32.9[9.0—120]), no epidural (4.3 [1.6—11.1]) and third degree perineal tear (20.0[1.3—314]).
Discussion
Toourknowledge,thisisoneofthefewstudiesthateval- uatedspecificriskfactorsassociatedwithUIandAI4years afterfirstdelivery.Onepreviousstudy,whichlookedatspe- cificriskfactorsforUIandAI,wasbasedondatacollected 6months after firstchildbirth [16]. This study found that riskfactorsweredifferentforpostnatalUI(shoulderdysto- ciaandvaginaldelivery)vs.postnatalAI(ageover35years, smoking,durationofthesecondstageoflabormorethanan hourandthirddegreeperinealtear).
Wefoundthatdifferentriskfactorswereassociatedwith UIonly(i.e.,withoutAI),AIonly,andUI+AI4yearsafterfirst delivery.RiskfactorsforUIonlywerematernalageatfirst delivery≥30,pre-existingUIandpregnancyUI.Riskfactors associatedwith AI only were length of the second active stage>20minutesandthirddegree perinealtear.Riskfac- torsassociatedwithUI+AIwereage≥30,noepidural,third degreeperinealtear,andUIbeforepregnancy.
The relatively long period of follow-up in our study (4yearsafter first delivery) is an important advantage as theprevalence of postpartum UI tends todecrease spon- taneouslyin thefirst postpartum year[17]. Nevertheless,
Table1 Continencecomplaints4yearsafterfirstchildbirth.Wherepercentagesdonotaddto100%,thereweresome missingdata(from0to3.3%).
Continencetroubles4yearsafterfirstchildbirth
n=627 n(%)
Urinaryincontinence(UI) No 438(71)
Yes 181(29)
SeverityofUI(Sandvikscore) NoUI 438(71)
Slight 110(18)
Moderate 42(7)
Severe 16(3)
TypeofUI(%amongwomenwithUI) Stress 55(30)
Urgency 12(7)
Mixed 109(60)
UIbothersome(%amongwomenwithUI) Notaproblem 24(13)
Abitofaproblem 107(59)
Quiteaproblem 27(15)
Aseriousproblem 17(9)
Analincontinence(AI) No 525(84)
Yes 82(13)
TypeofAI(%amongwomenwithAI) Flatusonly 64(78)
Stool 18(22)
AIbothersome(%amongwomenwithAI) Notaproblem 1(1)
Abitofaproblem 36(44)
Quiteaproblem 13(16)
Aseriousproblem 30(37)
ourstudy has certain limitations. The sample size of the study was based on the number of subjects needed to havesufficientpower forshowingadifferenceintheout- comes between the two maternities that had different policiesforepisiotomy in ourinitialstudy [12].The study wasnot specifically designed tohave sufficient power to explore the specific effects associated withdifferent risk factors.Indeed,theconfidenceintervalsfortheestimates ofthe effects for severalrisk factors werewideand lack ofsufficientpowermayexplaintheabsenceofstatistically significantresultsforsomeoftheriskfactorsinthepresent study.In particular, the lack of statistical significance for theassociations between mode of delivery and outcomes (differenttypesofincontinence)islikelytobeduetoinsuf- ficient power. It is worth noting that the point estimates (oddsratios)suggestedalower,albeitnotstatisticallysignif- icant,riskforallthreeoutcomes(UIonly,AIonlyandUI+AI) forwomenwhodeliveredfollowingacesareansection.For reasonsofstatisticalpowerwe alsorenouncedconductan analysisbasedonthetypeofinstrumentusedfor delivery (forcepsorvacuum).
Our findings of specific associations between obstetric risk factors and prevalence of UI only, AI only and UI+AI may be due to differences in the underlying mechanisms ofinjuryfordifferenttypesofincontinence.Thetwomain mechanismsproposedtoexplainpostnatalAIaresphincter injuryandpudendalneuropathy.In ourstudy,thespecific riskfactorsforAI(thirddegreeperinealtearandprolonged secondactivestage)arecompatiblewiththesemechanisms.
Prolongedactivesecondstageisassociatedwithpudendal
nervedamage[2].Evenfollowingrepair,thirddegreeperi- nealtearisassociatedwithAIyearsafterdelivery[18].
ConcerningpostnatalstressUI,themechanismsofinjury are still largely unknown [17]. Vaginal birth is likely to increasethemobilityoftheurethraor tobeaccompanied bylesionsofthelevatorani[3,4].However,urethramobil- ityreturns toprenatalvaluesa fewmonthsafterdelivery [19].Wijmaetal.foundnorelationbetweenurethramobil- ity and postnatal UI [20]. Dietz and Lanzarone found no link between levator ani avulsion and postnatal stress UI [4]. DeLancey et al. reported that only 16% of postnatal stress UI couldbe explainedbyurethra mobility,whereas urethraclosingpressurecouldaccountfor25%ofpostnatal de novo stressUI [21]. The relation between urethraclo- sure pressure and pregnancy remains unclear. Iosif et al.
foundclosurepressuretoincreaseduringpregnancyandto decrease after delivery,while Le Coutour etal. reported oppositefindings[22,23].Inourstudy,thefindingofanasso- ciation between maternal age and UI could be explained byalowerurethraclosurepressureasthelatterisknown todecreasewithincreasingmaternalage[24].Wearenot awareofanystudiesthathaveexaminedthelinkbetween pregnancyUIandurethraclosurepressureorurethralmobil- ity[17].
Inconclusion,ourresultssuggest thatUIandAI4years afterfirstdeliverydonotsharethesamesetofriskfactors.
These results are consistent with thehypothesis that the underlyingmechanismsofpostnatalincontinencedifferfor UI versus AI.This implies in turn thatdifferent strategies maybeneededforpreventionofUIandAI.
Table2 Risk factors for urinary incontinence (UI) only, anal incontinence (AI) only, and UI+AI. Multinomial logistic regression adjusted onmaternity.Other factorstested andnon-significant were:education level,a BMIgreater than 25kg/m2,gestationalageatfirstdelivery,afirstnewbornover4000g,pelvicfloorexercisesafterfirstdelivery,episiotomy atfirstdelivery,aseconddelivery,andan ongoingpregnancy.Casenumbersmaynotaddupbecauseofsomemissing dataforgivenriskfactors(from0to4.6%).
Variable n UIonlyadjusted
OR(CI95%)
AIonlyadjusted OR(CI95%)
IU+IAadjustedOR (CI95%)
Ageatfirstchildbirth
<30years 415 1 1 1
≥30years 212 2.27(1.47—3.49) 1.34(0.65—2.73) 2.65(1.29—5.46)
UIbeforepregnancy
No 565 1 1 1
Yes 33 6.44(2.19—19.0) 2.02(0.21—18.9) 32.9(9.00—120)
UIduringpregnancy
No 468 1 1 1
Yes 133 3.64(2.25—5.91) 1.57(0.64—3.90) 1.87(0.77—4.55)
Epidural
No 101 0.96(0.51—1.78) 1.52(0.59—3.92) 4.29(1.65—11.1)
Yes 526 1 1 1
Secondactivestage
≤20minutes 561 1 1 1
>20minutes 59 1.26(0.62—2.57) 2.86(1.15—7.13) 2.29(0.73—7.15)
Modeofdelivery
Spontaneous 368 1 1 1
Instrumental 209 1.16(0.74—1.81) 1.11(0.54—2.31) 0.96(0.43—2.11)
Cesarean 50 0.54(0.22—1.31) 0.61(0.14—2.79) 0.28(0.05—1.70)
Thirddegreeperinealtear
No 621 1 1 1
Yes 6 3.67(0.22—61.3) 20.9(1.73—252) 20.0(1.28—314)
Boldcharactersindicateasignificantassociation(P<0.05).
Disclosure of interest
Theauthorsdeclarethattheyhavenoconflictsofinterest concerningthisarticle.
Appendix A. Supplementary material
Supplementary material associated with this article can be found, in the online version, at doi:10.1016/j.purol.
2013.06.009.
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