Clinicalscenario..Apregnantmotherwithherhusbandcomestoseeyou.Sheisinherthirdtrimester.Bothofthemarelawyers.TheyhaverecentlyheardaboutcongenitalhypothyroidisminTelevisionandwantstodiscusswithyouhowtoknowiftheirunbornchildisaffected.Howwillyouadvicethem?1Clinicalscenario..ApregnContent…1.WhatiscongenitalHypothyroidism?2.CausesbehindCH?3.SignsandsymptomsofCH?4.HowtodiagnoseCH?5.IsCHinherited?6.HowtotestforCH?7.TreatmentofCH?2Content…1.WhatiscongenitalHWhatisCongenitalHypothyroidism?Isastateofinadequatethyroidhormoneproductioninnewborninfants.

Babieswhodonothaveenoughthyroidhormoneareoftenslowtogrow,aresluggish,andhavelearningdelaysandotherspecifichealthproblems.3WhatisCongenitalHypothyroidWhatarethecausesforthiscondition?1.Missingormisplacedthyroidgland

MostbabieswithCHaremissingtheirthyroidglandorhaveathyroidthatdidnotdevelopproperly.

Insomecases,thethyroidglandmaybesmallerthanusualormaynotbelocatedinthecorrectplace.InsomechildrenwithCH,thethyroidglandmayinsteadbeunderthetongueoronthesideoftheneck.2.HereditarycausesChildrenwiththeinheritedtypeofCHdonotmakeenoughthyroidhormoneeventhoughtheirthyroidglandappearsnormalinsizeandshape.3.Maternaliodinedeficiency4.Maternalthyroidconditionandmedications5.

Multiplebirths4Whatarethecausesforthiscwhatproblemsoccur?

.Poorfeedingandpoorsuck.Lowactivitylevel.Fewerbowelmovementsorconstipation.Swellingaroundtheeyes.Cool,pale,dryskin.thefontanelthatcloseslate1.Jaundice2.Hypotonia3.Umbilicalhernia4.Largeswollentongue5whatproblemsoccur?

.PIfleftuntreated

Coarse,swollenfacialfeaturesBreathingproblemsHoarse-soundingcryDelayedmilestones(sitting,crawling,walking,talking)Wide,shorthandsPoorweightgainandgrowthGoiter(enlargedthyroidglandcausingalumpintheneck)AnemiaSlowheartrateFluidbuild-upundertheskin(calledmyxedema)Hearingloss6Ifleftuntreated

Coarse,swolHowtodiagnoseCH?Familyhistoryshouldbecarefullyreviewedforinformationaboutsimilarlyaffectedinfantsorfamilymemberswithunexplainedmentalretardation.Maternalhistoryofathyroiddisorderandmodeoftreatment(whetherbeforeorduringpregnancy)7HowtodiagnoseCH?FamilyhistWhatisthechanceofCHbeinginherited?About80to85%ofthetime,CHiscausedwhenthethyroidglanddoes

notdevelopatall,ismisplaced,oristoosmall.Inabout15%ofcasesofCH,thethyroidglandappearsnormalbuttheamountofthyroidhormonemadeisreduced.

Thesecasesaremorelikelytobeinherited,butnotalways.

MostofthehereditarytypesofCHareinheritedinanautosomalrecessive

manner.Whenbothparentsarecarriers,thereisa25%chanceineachpregnancyforthechildtohaveCH.Thereisa50%chanceforthechildtobeacarrier,justliketheparents.And,thereisa25%chanceforthechildtohavetwoworkinggenes.8WhatisthechanceofCHbeingIfachildishavinginheritedformofCH,isgenetictestingavailable?

IfageneticdoctorsuspectsaninheritedformofCH,genetictestingmaybeavailabletoattempttodeterminethegenechangesthatcausedtheCH.

DNA

testing,canbedoneonabloodsample.9IfachildishavinginheritedCanitbetestedduringpregnancy?CHisnotusuallydetectablebeforebirth.Forthosethatmayhaveaninheritedform,genetictestingcanconfirmonlyaportionofthehereditarycases.

However,prenataltestingisrarelydoneforCHbecausetreatmentissoeffective.IfachildhasahereditaryformofCH,andifthegenechange(s)havebeenfoundinthechild,DNAtestingispossibleduringfuturepregnancies.10CanitbetestedduringpregnaWhatothertestingisavailable?

Bloodteststodetecttheamountofthyroidhormone(T4)thyroidstimulatinghormone(TSH).IfachildhasapositivenewbornscreenforCH,Thyroiduptakeandscan

orUltrasound11WhatothertestingisavailablWhatisthetreatmentforCH?

Medication

…L-thyroxine

…..Thedoctorandendocrinologistwilldecidehowmuchandhowoften.

…..Doctorswillincreasetheamountofmedicationaschildgrows.*L-thyroxineneedstobetakenona

dailybasisthroughchild’swholelife.

12WhatisthetreatmentforCH?

Monitoring

-weight,height,developmentandoverallhealth.

-regularbloodtests-levelofthyroidhormone.

DevelopmentalEvaluation

-

Ifchildshowdelaysincertainareasoflearningorspeech,extrahelpcanbearranged.13Monitoring

-weight,heigWhathappenswhenCHistreated?

Startedsoonafterbirth-usuallyhavenormalgrowthandintelligenceandcanlivetypicalandhealthylives.

Iftreatmentisnotstarteduntilseveralmonthsafterbirth,delaysorlearningproblemsmayoccur.Thelevelofdelayvariesfromchildtochild.14WhathappenswhenCHistreateEpidemiologicalstatisticsDoesCHhappenmorefrequentlyinacertainethnicgroup?Ithappensmoreofteninbabiesfrompartsoftheworldinwhichthereisnotenoughiodineinthefoodandwater.ItisalsomorecommoninbabiesofHispanicandNativeAmericanancestry.ItislesscommoninbabiesofAfrican-Americanancestry.

HowmanypeoplehaveCH?-Aboutoneinevery3000to4000babiesbornintheUnitedStateshasCH.

-TwiceasmanygirlshaveCHthanboys.

15EpidemiologicalstatisticsHowClinicalscenario..Apregnantmotherwithherhusbandcomestoseeyou.Sheisinherthirdtrimester.Bothofthemarelawyers.TheyhaverecentlyheardaboutcongenitalhypothyroidisminTVandwantstodiscusswithyouhowtoknowiftheirunbornchildisaffected.Howwillyouadvicethem?16Clinicalscenario..ApregnInsummaryAnalysisinUnitedStatesshowsaboutoneinevery3000to4000babiesborninthehasCH.IfachildishavingCH,

85%-misplacedormissingthyroidgland.10%-15%-hereditarycau