prenatal screening tests - welcome - mount sinai … · 2 a guide to understanding prenatal ... ,...

What are prenatal screening tests?

A guide to understandingprenatal screening tests for:• DownSyndrome• Trisomy18• OpenNeuralTubeDefects

Newprenatalscreeningtestsarenowavailableforallwomen.

FORWOMENANDTHEIRFAMILIES

Earlyon inyourpregnancy,youcandecidewhether or not you would like to haveprenatal screening.These testsareoptional- it is your choice whether or not to havethem. The purpose of this Guide is to giveyouinformationtohelpwithyourdecision.

• Thesearebloodtests,sometimeswithanultrasound,whicharedonestartingat11weeks ofpregnancy.• TheyareSCREENINGtests,whichmeanstheytellyouyourCHANCEofhavingababy withDownsyndrome,trisomy18oranopenneuraltubedefect.• Screeningtestscannottellyouforsurewhetherornotyourbabyhasoneofthesethree conditions,onlythechanceofthis.• Tofindoutforsure,youwouldhavetodecidewhethertohaveaDIAGNOSTICtest(see page10).• Prenatalscreeningcannotfindeverybirthdefect.

2 A guide to understanding prenatal screening tests - for women and their families

TheConditions:• DownSyndrome• Trisomy18• OpenNeuralTubeDefects

Downsyndrome*PeoplewithDownsyndromeusuallyhavemildtomoderateintellectualdelay.IndividualswithDownsyndromemayhaveagreaterincidenceofhealthconditionsthantheaveragepersonsuchasheart,stomach, bowel, thyroid, vision and hearing problems. Treatment is available for many of theseconditions.EachpersonwithDownsyndromeisdifferent.Thereisnowaytotesthowseriousthedisabilitieswillbe.PeoplewithDownsyndromegenerallyliveintotheirfifties.Ingeneral,aboutonein1000birthshasDownsyndrome.ThechanceofhavingachildwithDownsyndromeincreaseswiththemother’sage.

Trisomy18*Babieswithtrisomy18havebothmentalandphysicaldisabilities.Manypregnancieswithtrisomy18willmiscarry.Mostbabiesbornwithtrisomy18donotsurvivepastthefirstfewmonthsoflife.Ingeneralaboutonein6,000birthshastrisomy18.Thechanceofhavingachildwithtrisomy18increaseswiththemother’sage.

OpenNeuralTubeDefects*Theseconditionsoccurwhenthebrainorspinalcorddoesnotformproperly.Anopenneuraltubedefectinvolvingthespinalcordiscalledspinabifida.Spinabifidacausesphysicaldisabilitiessuchasdifficultywalking,andcontrollingthebladderand/orbowel.Peoplewithspinabifidamayalsohavementaldisabilities.Treatmentcanhelpwithmanyofthephysicaldisabilities.Anopenneuraltubedefect involving the brain is called anencephaly. A baby with anencephaly will be stillborn or dieshortlyafterbirth.InCanada,thechanceofhavingababywithanopenneuraltubedefectisabout1outofevery2000births.Thechanceofachildbeingbornwiththisconditiondoesnotincreasewiththemother’sage.

* Alistofresourcesonpage11canleadyoutomoreinformationaboutDownsyndrome, Trisomy18orOpenNeuralTubeDefects.

Familyhistory:Othertestsorgeneticcounsellingmaybesuggestedifyouoryourpartnerhaveaclosefamily memberwho was born with a birth defect or has a serious health problem.Pleasetalktoyourhealthcareproviderformoreinformation.

Whatareyourchancesofhavingababywithoneoftheseconditions?

Itisimportanttorememberthatmostbabiesarebornhealthy.

The chance of having a baby with a chromosomecondition like Down syndrome and trisomy 18increaseswiththeageofthemotherasshownintheTablebelow.

Remember…You might decide to have prenatal screening becauseyou want to find out your chance of having a baby withDown syndrome, trisomy 18 or open neural tube defect.This is determined from your age, the blood tests and/orultrasound.

A screening test gives you more information about yourchanceofhavingababywithoneoftheseconditionsthanthechanceshowninthetableabove.

Everywoman,nomatterwhatage,hasa2-3%chance(2or3chancesin100)ofhavingababywithsomekindofbirthdefect.Birthdefectscanincludeconditionslikeheartproblemsandextratoes.

Mother’sage(years)

20

25

30

35

40

45

ChanceofDownsyndrome

1in1,650

1in1,250

1in950

1in385

1in100

1in30

Chanceofanychromosomeconditionincludingtrisomy18,DownSyndromeandothers

1in530

1in480

1in390

1in180

1in65

1in19

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Chanceofchromosomeconditionswithvaryingmaternalage:

ArePrenatalScreeningTestsrightforyou?

Manywomenhaveadifficulttimedecidingwhetherornottohaveprenatalscreeningtests.SomewomenfindithelpfultoreadallofthisGuidefirst,beforemakingadecision.

Remember,itisyourchoicewhetherornottohaveaprenatalscreeningtest.

Herearesomethingstothinkaboutthatmighthelpyoumakeyourdecisionandmaybediscusswithyourpartner,healthcareprovider,familyorfriends.

1. DoyouwanttoknowthechanceofyourbabyhavingDownsyndrome,trisomy18oropenneural tubedefect? •ThereisnocureforDownsyndrome,trisomy18oropenneuraltubedefect. •Ifoneoftheseconditionsisfound,yourhealthcareprovidermaysuggestadditionaltestsand/or changeinthewayyourbabyisdelivered. •Somepeoplehavescreeningbecausetheywouldliketheinformationbeforebirth,orwouldliketo prepareforachildwithspecialneeds. •Somepeoplehavescreeningbecausetheywouldconsidergivingthebabyupforadoptioniftheir babywasfoundtohaveoneoftheseconditions. •Somepeoplehavescreeningbecausetheywouldhaveanabortioniftheirbabywasfoundtohaveone oftheseconditions.

2. Howwillthisinformationaffectyourfeelingsthroughoutyourpregnancy? •Manywomenworryiftheirtestresultssaythatthechanceofhavingababywithoneofthese conditionsishigherthanexpected(calledscreenpositiveseepage8).

3. Ifyourscreeningtestresultsaysthechanceishigherthanexpected(calledscreenpositiveseepage8), youwillneedtodecideifyouwantdiagnostictesting(seepage10)tofindoutforsureifyourbabyhas Downsyndrome,trisomy18oropenneuraltubedefect.

4. Diagnostictestingwilltellforsureifyourbabyhasoneoftheseconditions,buthasasmallchanceof miscarriage.Areyouwillingtotakethatrisk?Forinformationaboutdiagnostictestingseepage10.

5. Ifmoretestingshowsyourbabyhasaconditionforsure,whatwillyoudowiththeinformation? Youwillneedtodecideifyouwanttocontinuethepregnancyorhaveanabortion.

6. IfyoufindoutforsurethatyourbabyhasaconditionlikeDownsyndrome,youcanplanforthe birthofyourchildandfindoutfromotherswhatitisliketoraiseachildwiththiscondition.Would thisinformationbehelpfultoyoubeforebirth?Remember,toknowforsureyouhavetohavea diagnostictestwhichhasasmallchanceofmiscarriage.

7. Ifyouhaveachildwithmentaland/orphysicaldisabilities,howmightthisaffectyourlife,yourother children,yourrelationshipwithyourpartnerandyourextendedfamily?


Otherthingstothinkabout:•ScreeningtestswillfindmostbabieswithDownsyndrome,trisomy18oropenneural tubedefects,butnotall.Formoreinformationseepage8.•Screeningtestswillnotfindeverykindofbirthdefect,notestcandothis.•PrenatalscreeningtestsmightalsofindconditionsotherthanDownsyndrome, trisomy18andopenneuraltubedefectsbutthesearethecommonest.

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Doyouwanttohaveprenatal screening or not?

Thechoiceisyours.

Decisionsyoumayneedtomake:IfyouareUNDECIDEDaboutprenatalscreening:YoumaywanttoreadallofthisGuidebeforemakingadecision.Youcandiscussyouroptionswithyourhealthcareproviderorgeneticcounsellor.Youcanhaveprenatalscreeningandmakeachoicewhetherornottocontinuetheprocessateachstep.

IfyoudecideYEStoprenatalscreening:

Youwillneedtodecidewithyourhealthcareproviderwhichprenatalscreeningtestisrightforyou(seepage6)

If your prenatal screening test is screenPOSITIVE, you will need to decide if youwillhavediagnostictesting,keepinginmindthatthereisasmallriskofmiscarriage.

IfyoudecideYEStodiagnostictesting:Youwillneed todecidewhatyouwilldo if the result shows your baby hasoneoftheseconditions.Willyouhavean abortion? Will you continue thepregnancy?Willyougivethebabyupfor adoption?

IfyoudecideNOtoprenatalscreening:

Youmayhavedecidedthatyoudon’twanttoknowifyourbabyhasoneoftheseconditions,youwouldpreferto“takewhatcomes”.

Youmayhavedecidedthatyouwouldnotwanttohaveadiagnostictestunderanycircumstancesbecauseofthesmallchanceofmiscarriage.

Youmayhavedecidedthatyouwouldnothaveanabortionifdiagnostictestingconfirmedthatyourbabyhadoneoftheseconditions.

Ifyouareover35yearsofageatyourduedate:

•Youneedtodecideifyouwouldprefer diagnostictestingwhichcantellforsureif yourbabyhasoneoftheseconditionsbuthas ariskofmiscarriage,or…

•Ifyouwouldprefertohaveprenatalscreening firstandmakeadecisionaboutdiagnostic testingdependingonthescreeningtestresults.

Forwomenover35years of age at their due date:Women35yearsofageandoverattheirduedatecandecidenottohaveaprenatalscreeningtestbutgodirectlytodiagnostictestingsuchasCVSandamniocentesis.Rememberthatscreeningtestsgiveabetterestimateofriskthanagealone,forthoseaged35to39.Inparticular,women40andovershouldconsidercounsellingabouttheprosandconsofscreeninganddiagnostictesting.Formoreinformationaboutdiagnostictestingseepage10andtalktoyourhealthcareprovider.

Insomeareas,thishaschangedandappliestowomen 40yearsofageandoverattheirduedate.

IhavedecidedthatIwanttohaveprenatalscreening,nowwhat?Youneedtochooseaprenatalscreeningtestwithyourhealthcareprovider.Thefollowingtablewillhelpyouunderstandthedifferentprenatalscreeningtests.

Test/Procedure

1stbloodsample

Nuchaltranslucencyultrasound

2ndbloodsample

Resultsavailableat:

Detectionrate(Accuracy)

Falsepositiverate

Diagnostictestifprenatalscreeningtestispositive

Diagnostictestresultsavailableat:

Abortion–ifyoudecidetohavethis–couldbeperformedat:

Or:Continuationwithpregnancy

FirstTrimesterScreening(FTS)

11-14weeks

11-14weeks

NONE

12-15weeks

Ofevery100pregnancieswithDownsyndrome,about80-85willbedetected(80-85%)

About3to9outof100pregnancies(3-9%)

CVS11-13weeksIfCVSisnotavailable,youcouldhaveamniocentesisdiagnostictestingasdescribedinthenextcolumn➔

13-15weeks

13-23weeksAbortiontimingwilldependonlocalavailability

Birth

IntegratedPrenatalScreening(IPS)

11-14weeks

11-14weeks

15-20weeks

16-21weeks



Amniocentesis15-22weeks

17-24weeks


Birth

SerumIntegratedPrenatalScreening(SIPS)

11-14weeks

NONE

15-20weeks

16-21weeks


About2to7out of 100pregnancies(2-7%)


17-24weeks


Birth

Ifyourfirstvisitwithyourhealthcareproviderisbefore14weeks(3-1/2months)ofpregnancy:• Youcanhaveoneofthenewprenatalscreeningtests:FirstTrimesterScreening, IntegratedPrenatalScreeningorSerumIntegratedPrenatalScreening.• Thestepsinvolvedineachofthesetestsandtheiraccuracyaredescribedinthetablebelow.

NuchalTranslucency(NT)ultrasoundisavailableinmostmid-sizeorlargercities.Ifyouliveinanareawherethisspecialultrasoundisnotavailable,youcanstillhaveSIPS.

NuchalTranslucencyisafluid-filledspaceatthebackofeverybaby’sneck.Anultrasoundtomeasure thisisdonebetween11and14weeksofpregnancy.Thechanceofacondition,likeDownsyndrome,is higherwhentheNTmeasurementislargerthanexpected.

FTSofferstheearliestavailableresultsbutrequiresabloodtestforneuraltubedefectslaterinthepregnancy.

FTSisnotavailableinallcommunities.Pleasecheckwithyourhealthcareprovider.

IPSandSIPSarealittlemoreaccuratethanFTSandincludescreeningforneuraltubedefects,butthisisa2-stepprocessand

resultsareavailablelaterinthepregnancy.


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Ifyourfirstvisitwithyourhealthcareproviderisafter14weeks(3-1/2months)ofpregnancy:• YoucanhaveTripleorQuadrupleprenatalscreening.Inmostareastriplescreeninghasbeenreplaced byquadruplescreeningbecauseitisalittlemoreaccurate.

• Thestepsinvolvedineachofthesetestsandtheiraccuracyaredescribedinthetablebelow.

Test

Bloodsample

Resultsavailableat:

Detectionrate(Accuracy)

Falsepositiverate

Diagnostictestifprenatalscreeningtestispositive

Diagnostictestresultsavailableat:

Abortion–ifyoudecidetohavethis–couldbeperformedat:

Or:Continuationwithpregnancy

TripleScreening

15-20weeks

16-21weeks

Ofevery100pregnancies withDownsyndrome,about70willbedetected(70%)

About7outof100pregnancies(7%)


17-24weeks


Birth

QuadrupleScreening

15-20weeks

16-21weeks

Ofevery100pregnancies withDownsyndrome,about75to85willbedetected(75-85%)



17-24weeks


Birth

Howaccurateareprenatalscreeningtests?

DownsyndromeThedetectionandfalsepositiveratesinthetableonlyrefertoDownsyndrome.Thisisbecausetrisomy18israreandwedonothaveexactnumbersforit.

Trisomy18Generally,forallofthetestslisted,thedetectionrateoraccuracyislessfortrisomy18thanwhatitisforDownsyndrome.Saidanotherway,thesetestsarenotquiteasgoodatmeasuringthechanceofhavingababywithtrisomy18(detectionrate)asmeasuringthechanceofhavingababywithDownsyndrome.

OpenneuraltubedefectsScreeningforopenneuraltubedefectsconsistsofabloodtestdonebetween 15-20 weeks. This is done as part of IPS, SIPS, Quad orTriplescreeningorasanadditionalbloodtest ifawomanishavingFTS. The ultrasound done at about 18 weeks of pregnancy alsogives information about open neural tube defects. Of every 100pregnancies with an open neural tube defect, 80 (or 80%) will bedetectedwithprenatalscreening.

Rememberthatmostbabiesarebornhealthy.

OOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO


Understandingyourresults:

This is a picture of the results if 1000 women have IntegratedPrenatalScreening.Forexample,if1,000womenofanyagehaveIntegratedPrenatalScreening,between20and40(or2-4%)willhavea“screenpositive”resultforDownsyndrome.Thismeans they are at increased risk of having a baby with Down syndrome. If all ofthosewomenhavediagnostictesting(seepage10)tofindoutforsureiftheirbabieshaveDownsyndrome,onlyoneofthemwillbefoundtohaveababythatactuallyhasDownsyndrome.

This is explained in the chart. Each circle represents 1 pregnant woman who hadIntegratedPrenatalScreening(IPS).Thereare1,000pregnantwomen(circles).

SCREENNEGATIVEO Circles represent women whose prenatal screening result will be screennegative for Down syndrome. 960 to 980 women out of 1,000 will have ascreennegativeresult.

FALSEPOSITIVERESULT Circlesrepresentwomenwhoseprenatalscreeningresultisscreenpositivefor

Downsyndrome.19to39womenoutof1,000willhaveafalsepositiveresultandwillhaveababythatdoesnothaveDownsyndrome.

TRUEPOSITIVERESULT Circlerepresentsatruepositiveresult.About1womanoutof1,000willhave

atruepositiveresult–ababywhohasDownsyndrome.

Outof100pregnancieswithDownsyndrome,IPSwillfind85to90,andwillmiss10to15.

Rememberthatabout1pregnantwomanin1,000willhaveababywithDownsyndrome.

Ifyourresultisscreenpositive,youcantalktoyourhealthcareprovideraboutmoretesting.Diagnostictesting(page10)isnecessarytotellifyourbabyhasaconditionforsure.Ifyourresultisscreenpositiveforaneuraltubedefect,youmayhavetheoptionofadetailedultrasoundat18to20weeksinsteadofamniocentesis-thiswillvarydependingonwhereyoulive.Geneticcounsellorsareavailabletodiscussyourtestresults.Theycanhelpyoumakeadecisionaboutdiagnostictesting.Theywillsupportyourdecisionnomatterwhatyoudecide.

Ifyourscreeningtestresultisscreenpositiveandtestingsaysthebabyhastheconditionforsure,youwillbeaskedifyouwanttocontinuethepregnancyorhaveanabortion.Geneticcounsellorsareavailabletodiscusswhatyourresultsmeanandyourchoices.Youdon’thavetodecidebeforetestingwhatyouwoulddo.Yourhealthcareproviderwillalsodiscussyourchoiceswithyou.Youmaywanttodiscussthiswithyourpartner,friendsorfamily.


9

What if they tell me my screening result isSCREENNEGATIVE?

The chance of your baby having Downsyndrome, trisomy 18 or open neuraldefectisLOWERthanexpected.

Is a SCREEN NEGATIVE resultaccurate?

There is less than a 1 in 1,000chanceofyourbabyhavingDownsyndromethatwasnotidentifiedbythescreeningtest.

Whenyourbabyisborn,ifheor she does not have any ofthese conditions, your resultwasaTRUENEGATIVE.

Understandingyourresults:Whentheytellmemyresult,howwillIknowwhatitmeans?

What if they tell me my screening result is SCREENPOSITIVE?

The chance of your baby having Down syndrome,trisomy18oropenneuraltubedefectisHIGHERthanexpected.

IsaSCREENPOSITIVEresultaccurate?Most screen positive results turn out to befalse,eitherbydiagnostictestingorthebirthofababywhodoesnothaveDownsyndrome,trisomy18oropenneuraltubedefect.ThisiscalledaFALSEPOSITIVE.

What ifaSCREENPOSITIVEresult isnotfalse?

About1outof1,000womenwillhaveaTRUEPOSITIVEresult,whichmeansthatafterdiagnostictestingorbirth,thebabydoeshaveDownsyndrome,trisomy18oranopenneuraltubedefect.

Every pregnancy has 2 or 3 chances in100(2-3%)ofhavingaconditionthatisnotfoundbyprenatalscreeningtests.

Itisimportanttorememberthatnotestcandetecteverytypeofbirthdefect

Diagnostictests

YouhavealreadylearnedthatscreeningtestscantellyouyourchanceofhavingababywithDownsyndrome,trisomy18andopenneuraltubedefects.

Diagnostictestscantellforsureifyourbabyhasoneoftheseconditions.Thesediagnostictestsareavailableonlyifyourscreeningtestresultispositiveorifyouare35yearsofage(insomeareas,thishaschangedto40yearsofage)orolderatyourduedateandincertainothersituations.

ChorionicVillusSampling(CVS)CVSisatestwhichtellsforsureifyourbabyhasDownsyndromeortrisomy18.Thistestisusuallydonebetween 11and 13weeksofpregnancy.Usingultrasound,a smallpieceof tissue is removedfromtheplacentafortesting,usuallythroughthevagina,butsometimesthroughtheabdomen.Anywomancanhaveamiscarriageatthistimeofpregnancy.IfshehasCVS,thisriskisincreasedbyanextraonein100(1%).Theresultisavailablein2-3weeks.Formoredetails,discussCVSwithyourhealthcareprovider.CVSisnotavailableinallareas.

AmniocentesisThistestcantellforsureifyourbabyhasaconditionlikeDownsyndromeortrisomy18.Sometimesitisusedtotellifyourbabyhasanopenneuraltubedefect.Thetestisusuallydonebetween15and22weeksofpregnancy.Usingultrasound,aneedleisinsertedthroughtheabdomenintothefluidaroundthebabyandasmallamountofamnioticfluidiswithdrawn.Theneedledoesnottouchthebaby.Anywomancanhaveamiscarriageatthistimeofpregnancy,but,ifshehasamniocentesis,thisriskisincreasedanextra1in400(0.2%).Newstudieshaverecentlyshownthattheriskofmiscarriagemaybeevenlower,possiblyaslowas1in1,600(0.06%).Theresultsareavailablein2-3weeks.Formoredetails,pleasetalktoyourhealthcareprovider.

Mosttimes,amniocentesisorCVSwillshowthatyourbabydoesnothaveDownsyndrome,ortrisomy18,butthesetestscannotfindeverycondition.Evenafteranormalresult,thereisachanceofhavingababywithadifferentconditionsuchasaholeintheheartormentaldisability.


Awordaboutunexpectednews:Ifyouhavediagnostic testingandtheresultsconfirmthatyourbabyhasDownsyndrome, trisomy18oropenneuraltubedefect,geneticcounsellorsareavailabletohelpyoudiscussyouroptions:continuingthepregnancy,adoptionorhavinganabortion.Makingadecisionisnoteasy.Geneticprofessionalscanhelpwithfindingresourcessuchassupportgroups,thatmaybehelpfultoyouduringandafteryourdecision-making.Therearehealthcareprovidersavailabletohelpyouandoffersupportnomatterwhatdecisionyoumake.

Thechoiceisyours.


Additionalsourcesofinformation:

CanadianAssociationofGeneticCounsellors:http://www.cagc-accg.caor905-849-8299ListofmedicalgeneticcentreslocatedacrossCanada.

CanadianDownSyndromeSociety:http://www.cdss.caor1-800-883-5608MoreinformationaboutDownsyndromewithlinkstolocalparentsupportgroups.

TheGeneticsHomeReference-YourGuidetoUnderstandingGeneticConditions:http://www.ghr.nlm.nih.govAnexcellentsitetolearnmoreaboutgeneticsincludingDownsyndrome,trisomy18andmore.

MarchofDimes:http://marchofdimes.com/Excellentsourceofinformationaboutpregnancyincludingcommonprenataltests,complicationsduringpregnancy,thingstoavoidduringpregnancy,birthdefectsetc.

Motherisk:http://www.motherisk.org/or416-813-6780or1-877-327-4636Information service for women who have been exposed to environmental agents, drugs and alcoholduringpregnancy.

OntarioMultipleMarkerScreening(MMS)Program:http://www.lhsc.on.ca/programs/rmgc/mss/Informationonprenatalscreeningtests.

S.O.F.T.SupportOrganizationForTrisomy18,13andRelatedDisorders:http://www.trisomy.orgor1-800-716-7638or585-594-4621Moreinformationabouttrisomy18.

SpinaBifidaandHydrocephalusAssociationofCanada:http://www.sbhac.caor1-800-565-9488Moreinformationaboutspinabifida.

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The Genetics Education Project

TheGeneticsEducationProjecthttp://www.mtsinai.on.ca/FamMedGen/TodownloadacopyofthisGuide.

©August2007

Prenatalscreeningtimeline:

Whenwouldyourscreeningtesthappen?

If your prenatal screening test shows an increased chance of Downsyndrome,trisomy18oropenneuraltubedefectsyoumaydecidetohavediagnostictesting.Informationaboutdiagnostictestingisalsoavailableinthisguide.


Blood testand Ultrasound

RESULTSAVAILABLE

You are pregnant

Weeks11-14

Weeks12-15

Weeks15-20

Weeks16-21

FirstTrimesterScreening

(FTS)

Blood testand Ultrasound

Secondof2bloodtests

RESULTSAVAILABLE

IntegratedPrenatal

Screening(IPS)

Firstof2bloodtests

Secondof2bloodtests

RESULTSAVAILABLE

SerumIntegratedPrenatal

Screening(SIPS)

Blood test

RESULTSAVAILABLE

Tripleand

QuadrupleScreening

prenatal screening tests - welcome - mount sinai … · 2 a guide to understanding prenatal ... ,...

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