Contraception Fact Sheet
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KEN ROPER BSc(Med) MBBS FRANZCOG Obstetrics, Gynaecology, Colposcopy and Laparoscopic Surgery Conjoint Lecturer UNSW Provider Number 458915B 32/20‐24 Gibbs St Miranda, NSW 2228 Ph: 9524 2129 www.drkenroper.com.au 31 st January 2012 Contraception Fact Sheet The main purpose of contraception is to avoid conceiving during sexual activity. This can be achieved by a number of ways. Classifications of contraception are many and varied. These include natural versus hormonal, permanent versus reversible, those requiring action only during intercourse and those independent of intercourse. There are certain health conditions, pregnancy history and age of the couple that may preclude particular contraceptive methods. The following information is to be seen as a guide only and is not a substitute for consultation with a medical practitioner. Pearl Index The Pearl Index of a contraceptive technique refers to its effectiveness. It is calculated as the number of women who will become pregnant per 100 women per year having regular sexual activity. For example a Pearl Index of 2 means that for a 100 couples who are regular intercourse 2‐3 times per week using a particular form of contraception for 12 months that there will be two of them who will become pregnant during that time. Therefore the lower the Pearl Index the greater degree of contraception is being achieved. Withdrawal/Coitus Interruptus This is a surprisingly frequently used form of contraception in many age groups. It has the benefits of being simple, cheap and readily employable but the marked disadvantage of potentially reduced sexual enjoyment through fear of unintended pregnancy. Timing is critical and unfortunately there are sperm that are released from the male penis prior to ejaculation and this may be a contributing factor to its failure rate. As testimony to its success are those patients who immediately conceive after cessation of using this technique. Billing’s Method This method relies upon the observation of the cervical mucous. Around the time of ovulation this mucous becomes clear, more slippery and heavier. This will usually occur 14 days prior to the next menstrual period (not necessarily 14 days after the previous menstrual period as the first part of the menstrual cycle can vary in its length). During this time of perceived ovulation intercourse can either be avoided or alternative measures such as barrier methods or withdrawal used. This technique is particularly useful for those couples where the women has a regular menstrual cycle and is also able to observe these changes in her cervical mucous. Condoms These are a readily available form of contraception which have the added benefit of a degree of protection against some sexually transmitted infections. It is important that condoms are used properly. They can deteriorate if stored in a hot environment (eg glove box of the car), or if they rupture during sexual activity, or if they slip off after ejaculation when the male penis is no longer erect. The quoted Pearl Index for condoms is 5‐15. Diaphragm The contraceptive diaphragm is used less frequently these days. They do have the advantage of being able to be inserted well before sexual intercourse takes place and thereby not interfere with foreplay. The obvious disadvantage is when sexual intercourse had not been foreseen and the diaphragm not close at hand. Diaphragms need fitting by a health care professional such as a general practitioner, gynaecologist or a Family Planning Clinic. They have a similar Pearl index to condoms of 5‐15.
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Transcript of Contraception Fact Sheet
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KEN ROPERBSc(Med)MBBSFRANZCOGObstetrics,Gynaecology,ColposcopyandLaparoscopicSurgeryConjointLecturerUNSWProviderNumber458915B
32/2024GibbsStMiranda,NSW2228
Ph:95242129www.drkenroper.com.au
31stJanuary2012
ContraceptionFactSheet
Themainpurposeofcontraceptionistoavoidconceivingduringsexualactivity.Thiscanbeachievedbyanumberofways.Classificationsofcontraceptionaremanyandvaried.Theseincludenaturalversushormonal,permanentversusreversible,thoserequiringactiononlyduringintercourseandthoseindependentofintercourse.Therearecertainhealthconditions,pregnancyhistoryandageofthecouplethatmayprecludeparticularcontraceptivemethods.
Thefollowinginformationistobeseenasaguideonlyandisnotasubstituteforconsultationwithamedicalpractitioner.
PearlIndex
ThePearlIndexofacontraceptivetechniquereferstoitseffectiveness.Itiscalculatedasthenumberofwomenwhowillbecomepregnantper100womenperyearhavingregularsexualactivity.ForexampleaPearlIndexof2meansthatfora100coupleswhoareregularintercourse23timesperweekusingaparticularformofcontraceptionfor12monthsthattherewillbetwoofthemwhowillbecomepregnantduringthattime.ThereforethelowerthePearlIndexthegreaterdegreeofcontraceptionisbeingachieved.
Withdrawal/CoitusInterruptus
Thisisasurprisinglyfrequentlyusedformofcontraceptioninmanyagegroups.Ithasthebenefitsofbeingsimple,cheapandreadilyemployablebutthemarkeddisadvantageofpotentiallyreducedsexualenjoymentthroughfearofunintendedpregnancy.Timingiscriticalandunfortunatelytherearespermthatarereleasedfromthemalepenispriortoejaculationandthismaybeacontributingfactortoitsfailurerate.Astestimonytoitssuccessarethosepatientswhoimmediatelyconceiveaftercessationofusingthistechnique.
BillingsMethod
Thismethodreliesupontheobservationofthecervicalmucous.Aroundthetimeofovulationthismucousbecomesclear,moreslipperyandheavier.Thiswillusuallyoccur14dayspriortothenextmenstrualperiod(notnecessarily14daysafterthepreviousmenstrualperiodasthefirstpartofthemenstrualcyclecanvaryinitslength).Duringthistimeofperceivedovulationintercoursecaneitherbeavoidedoralternativemeasuressuchasbarriermethodsorwithdrawalused.Thistechniqueisparticularlyusefulforthosecoupleswherethewomenhasaregularmenstrualcycleandisalsoabletoobservethesechangesinhercervicalmucous.
Condoms
Theseareareadilyavailableformofcontraceptionwhichhavetheaddedbenefitofadegreeofprotectionagainstsomesexuallytransmittedinfections.Itisimportantthatcondomsareusedproperly.Theycandeteriorateifstoredinahotenvironment(eggloveboxofthecar),oriftheyruptureduringsexualactivity,oriftheyslipoffafterejaculationwhenthemalepenisisnolongererect.ThequotedPearlIndexforcondomsis515.
Diaphragm
Thecontraceptivediaphragmisusedlessfrequentlythesedays.Theydohavetheadvantageofbeingabletobeinsertedwellbeforesexualintercoursetakesplaceandtherebynotinterferewithforeplay.Theobviousdisadvantageiswhensexualintercoursehadnotbeenforeseenandthediaphragmnotcloseathand.Diaphragmsneedfittingbyahealthcareprofessionalsuchasageneralpractitioner,gynaecologistoraFamilyPlanningClinic.TheyhaveasimilarPearlindextocondomsof515.
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EmergencyContraception
Themedication,Postinor2,isaprogesteronebasedtabletthatcanbeusedinthecontextofanemergencywheretherehasbeenunintendedunprotectedintercoursearoundthetimeofthecyclewhenthewomanbelievesshemaybefertile.Itismosteffectiveassoonafterintercoursehasoccurredbutstillmaybeeffectiveupto72hoursafterwards.Itdoesnotrequireaprescriptionandcanbeobtainedfrommostpharmacists.Thisformofcontraceptionisnottoberelieduponasaroutinecontraceptionbecauseofitspotentialforfailurebutalsobecauseofitspotentialforcausingmenstrualirregularities.
CombinedOralContraceptivePill
Thecombinedoralcontraceptivepillhasbeenavailableforapproximately50yearsandcontainsbothoestrogenandprogesterone.Theoestrogencomponentofthepillisresponsibleforinhibitingovulation.Theprogesteronecomponentwillpreventtheliningofthewomb(endometrium)frombecomingtoothick.Indeedoneofthebenefitsofthepillistocausereducedmenstrualbleedinginapredictablefashionandalsoreduceperiodpain.Itisimportanttotakethepillasdirected.WhileithasaPearlIndexof0.8thiscanbemadelesseffectivebyomissionofthepill,malabsorptionofthepillbecauseofvomitingordiarrhoea,theuseofcertainantibioticsandtheconcurrentuseofmedicationsthateffectthemetabolismofthepillintheliver(someanticonvulsantdrugsandmedicationsusedtotreattuberculosis).Thepilliscomparativelysafebuttherearesomewomenforwhomitsuseisdangeroussuchasapasthistoryofdocumenteddeepveinthrombosis/pulmonaryembolism,recentbreastcancer,highbloodpressure,heartdiseaseandmaybeanaddedriskfactorforhardeningofthearteries.Oneoftenutilisedadvantageofamonophasicpill(apillwhichhasthesamestrengthandproportionofhormoneineverysingletablet)isthatitispossibletomanipulatethelengthofyourmenstrualcyclebystayingonthepillforgreaterthantheusualthreeweeksandtherebypostponingaperiodforimportanteventssuchasexamsandholidays.Therearesomewomenwhoinattemptingcyclemanipulationwillstilldevelopaperiodandsimplyisnotgoingtobeeffectiveforthem.Thistechniqueisgenerallynotsuitableforwomenwhoareonatriphasicpill(onethathasthreedifferentstrengthsofhormonesthroughoutthecycle).Thecombinedoralcontraceptivepillcannotbeusedinlactationbecauseofthepotentialforsuppressionofmilkproductionbytheoestrogenthatisinthepill.
Nuvaring
Thisisarecentlydevelopedcontraceptionwherebyaplasticringthatisimpregnatedwithbothoestrogenandprogesteroneisplacedbythewomanherselfwithinhervagina.Theplasticringwillleachoutbothhormonesforbetween2124daysbeforeitisremovedforafullsevendaysandanewringinsertedthefollowingweek.Thebenefitsofthistechniqueisalowerhormonaldoseandagreaterlikelihoodofcompliance.Thesedevicesgenerallydonotfalloutnorcauseinfectionbutanumberofwomenfeelawkwardabouthavingthisdeviceinsidetheirvagina.Itdoesnotinterferewithsexualintercourse.ItisaPearlIndexsimilartothatoftheoralcontraceptivepillof0.8.
ProgesteroneOnlyPill(Minipill)
Theprogesteroneonlypillistypicallyusedinthecontextofabreastfeedingmotherbutalsoforwomenwhohaveahistoryofthrombosisorcardiacdiseaseforwhomanoestrogencontainingpillwouldcontributefurthertoworseningofthoseunderlyingmedicalconditions.UnfortunatelyithasahigherPearlIndexof45.Thispillistakeneverysingleday.Itisbelievedthatitscontraceptiveactionisduetothickeningofthecervicalmucousandpreventingpenetrationofspermintotheuterinecavity.Thetimingofdosageoftheprogesteroneonlypillisfarmorecriticalthanthatofthecombinedoralcontraceptivepill.Theprogesteroneonlypillwillneedapproximatelythreehourstobeeffectiveanditwillwearoutthreehourspriortothenextday'stablet.Itthereforeneedstobetakenatthesametimeeverysingledaybutalsointercourseavoidedboththreehoursbeforeandthreehoursaftertakingthispill.
Implanon
Thisisahighlyeffectiveandquicklyreversiblecontraceptiveoption.Thisisaplasticrodthesizeofamatchstickthatisinsertedeitherbyageneralpractitionerorgynaecologistintheupperarmunderlocalanaesthetic.IthasaPearlIndexof0.2whichmakesitoneofthemorereliablereversibleformsofcontraception.ItiseffectiveforthreeyearsandbeingonthePharmaceuticalBenefitsSchemecostsapproximately$34.Amajorreasonfordiscontinuation,however,istroublesomeandprolongedmenstrualbleeding.Somewomenmayalsodevelopfluidretention,weightgainand
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headaches.Inthosewomenwhodonotsufferthesesideaffectsitisindeedaverycommendableformofcontraception.Itisparticularlyusefulforthosewomenwhohaveneverbeenpregnantandforthosewhoareforgetfulintakingthecontraceptivepill.
MirenaIntrauterineSystem
Thisdevicehasrevolutionisedcontraceptionandmanagementofheavyperiods.Historicallyintrauterinedeviceswereassociatedwithheavypainfulperiodsandwereinfrequentlyrequestedasaformofcontraception.Theydidhavetheadvantageofalongdurationofactionanddidnotrequireanyspecificactivitytoensuretheircontraceptiveactionincontrasttoothercontraceptivessuchascondomsortheoralcontraceptivepill.Howevertheywerenotpopularbecauseofthetendencytoincreasemenstrualbleedingandperiodpain.TheMirenadevicewasdevelopedinthe1980sandbecamecommerciallyavailableinpartsofEuropein1990andfinallyavailableinAustraliain1999andplacedonthePharmaceuticalBenefitsSchemein2003therebymakingtheseacheap,reliablealternativecontraception.
TheMirenaisimpregnatedwithaprogesteronehormonecalledLevonorgestrel.Ithastwomainbeneficialactions.Firstlyitwillcauseathickeningofcervicalmucoustomakethemucousimpenetrabletopassageofspermandsecondlythereisamarkedthinningoftheendometrium(liningofthewomb)whichresultsinextraordinarilylightmenstrualbleedingwherebyinsomewomenitwillbenonexistentaftertheinitialsixmonths.
ThePearlIndexoftheMirenadeviceis0.3whichisoneofthemoreeffectivereversibleformsofcontraceptionavailable.TheMirenahasafargreaterdegreeofacceptabilitybecauseofthereducedmenstrualbleedingthatisassociatedwithit.TypicallyinthefirstthreemonthsaftertheinsertionofaMirenadevicetherewillbeaprogressivethinningoftheendometriumwhichwillresultinapersistentandsometimestroublesomebrowndischargewhichwillsettledownwithtimeandperseverance.Thisbrowndischargeisalmostuniversallyabsentbysixmonths.Withinthisfirstthreemonthsthevolumeofmenstrualbloodthatislostisequivalentto15%ofwhatithadpreviouslybeen.By12monthsthisvolumeofmenstruallossisgreatlyreducedtojust3%.ItisnotuncommonforwomentoreporthavingverylittleinthewayofanyperiodatallforseveralyearswiththeMirenadeviceinplace.Thisisnotunhealthy.Normalmenstrualbleedingisduetothesheddingofendometriumthathasbecomethickduringanormalmenstrualcycle.Thisthickeningoccursinpreparationforthereceptionofafertilisedeggandifpregnancydoesnotoccurinthatparticularcyclethentheendometriumisshedtogetherwithlossofsomeblood.InthesituationofaMirenadevicebeingpresenttheendometriumissoextraordinarilythinthatthereissimplyverylittleornothingtoshed.Whilethisabsenceofmenstrualbleedingmayconcernsomewomenasasignofundiagnosedpregnancy,mostwomenwillenjoyhavinglessmenstruallossthanbefore.IntheunlikelyeventofpregnancywithaMirenadevicethewomanwillusuallyexperienceothersymptomssuchasbreasttenderness,nausea,changeintasteforcommonthingssuchascoffeeandtoothpaste.Ifanyofthesesymptomsweretooccurthenitwouldbeadvisabletodoahomepregnancytest.
ThetechniqueofinsertionofaMirenadeviceisrelativelystraightforward.Theoptimaltimeforinsertioniswithinthefirstthreedaysofamenstrualperiod.Inthissituationthecervixissofterandslightlydilatedascomparedtoothertimesthroughthemenstrualcycle.Thereisalsotheaddedreassurancethatitishighlyunlikelythatthewomanwillbepregnantatthattime.TherearesomewomenforwhomtheMirenaislessappropriate.Thesearewomenwhohaveneverbeenpregnantandthosethathavenotexperiencedlabour.Inthesesituationsthecervixcanbequitetightandtheinsertiontoopainfultoconductasanoutpatient.IfawomanwouldstillliketoutiliseaMirenadeviceforcontraceptionthenthisprocedurecanbedoneundergeneralanaesthesiainhospital.
Thereareasmallnumberofwomen,approximately1%,whoexperienceexpulsionoftheMirenadevice.ThiscanbedetectedbytheregularcheckingforthepresenceoftheMirenastringonamonthlybasis.Thisisdonebyinsertingafingerintothevaginatodetectthecervix(whichhasthesameconsistencyastheendofyournose)andfeelingforthestring.Itisimportantthatthestringisnotpulledonasthismaydislodgethedevice.Ifthestringisunabletobefeltthenyoushouldattendyourgeneralpractitionerormyselfassoonaspossibleforasimplespeculumexaminationtoseeifthestringispresent.Therearetimeswhenthestringmaycurluponitselfandretractwithintheuterinecavity.ApelvicultrasoundshouldbedoneatthattimetoseewhetherornottheMirenaisstillintheuterinecavity.TheriskofinfectionwithyourMirenadeviceisverylow.Thiscanoccurinthefirst20daysafterinsertionduetothetransgressionofthedevicethroughthethickcervicalmucous.Othersourcesofinfectionincludesexualtransmission.Itisimportantthatthesedevicesbeavoidedinthosepatientswhoarenotinastablesexualrelationshipbutareobviouslyideallysuitedforwomenwhoareinastablerelationship.IntheunlikelyeventofpregnancyoccurringitisimportantthattheMirenadeviceberemovedassoonaspossiblebecauseoftheriskofsepticmiscarriage.
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TheMirenadeviceshouldnotinterferewithsexualactivityinanyway.Theperformanceofpapsmearsisunchanged.IftheMirenadeviceprovestobeunsuitableforyouthenitsremovalisusuallyverystraightforwardandpainlessasanoutpatient.
PERMANENTCONTRACEPTION
LaparoscopicSterilisation
Thisprocedureisdoneundergeneralanaesthesiaasdaysurgeryinhospital.Asmallincisionismadewithintheumbilicusandacameraintroducedintotheabdominalcavity.Carbondioxidegasisthenusedtoinflatetheabdomensothataspaceiscreatedthroughwhichotherinstrumentscanbepassedthroughasecondsmallincisionapproximately35cmabovethepubicbone.Throughthisincisionanapplicatorisintroducedandaclipisappliedtoeachtube.Thisclipeffectivelyblocksthefallopiantubesothatspermandeggsareunabletomeet.
Thisshouldbeconsideredasapermanentprocedure.TherearecircumstanceswhereitmaybereversedbutthisrequiresseveralhoursofmicrosurgeryandMedicareandHealthFundsoffernofinancialrebateinthesecircumstances.Itshouldthereforebedoneinthecontextofsomeonewhoisabsolutelycertainthattheirfamilyiscomplete.Itisusefultoconsiderunpleasantscenariossuchasdeathofapartner,divorcefromapartner,disasteroccurringinfamilymemberssuchaschildhoodmalignancyorSuddenInfantDeathSyndrome.Thereisalsoacertaindegreeofregretassociatedwithpermanentformsofcontraceptionandthiswillobviouslyvarywiththeindividualcircumstance.Thelikelihoodoffallingpregnantevenafterthisprocedurehasbeensuccessfulisapproximately1:300duringthefirst10yearsaftertheprocedureisperformed.Thisiscomparabletothepregnancyratefollowinganapparentlysuccessfulvasectomy.
Essure
Thistechniqueinvolvestheplacementofametalandfabricdeviceintothefallopiantubeswheretheyjointheuterinecavity.Itisperformedundergeneralanaesthesiausingatechniquecalledhysteroscopy.Thisiswhereatelescope/cameraispassedthroughthecervicalcanalandthesedevicesintroducedintotheopeningofeachtube.Thisdoesnotrequireanincisionintheabdomen.Followingplacementofthesedevicescontraceptionneedstobecontinuedforthreemonthsuntilanxrayisdonetoconfirmthatthedeviceshavenotmigratedfromtheoriginallocation.Itisduringthesefirstthreemonthsthatthedevicecausesdenseadhesionstooccludethetube.Thisprocedureistotallyandutterlyirreversibleduetotechnicalreasons.Itisalsoassociatedwithasubsequentpregnancyrateofapproximately1:500.Thereisoccasionallytechnicaldifficultieswherebytheopeningofthetubecannotbenegotiatedbythefineinstruments.Thelikelihoodofthisisapproximately2%ofallpatients.
Vasectomy
DrRoperdoesnotperformvasectomy.Informationregardingthiswouldbebestobtainedfromeitheryourgeneralpractitioner,generalsurgeonoraspecialisturologist.Similarprinciplesapply,however,intermsofthecertaintyofamantoundertakethisdecisionowingtoitspermanentnature.Therearecircumstanceswherethisprocedurecanbereversedbutthisisnotalwaysmetwithsuccess.
