Screening for Diabetes in Pregnancy

DOI: 10.14260/jemds/2015/1826

ORIGINAL ARTICLE

SCREENING FOR DIABETES IN PREGNANCY

VidyaManoj Jadhav1, Nitu Sinha2

HOWTOCITETHISARTICLE:

VidyaManojJadhav, Nitu Sinha.“Screening for Diabetes in Pregnancy”.JournalofEvolutionofMedicalandDentalSciences2015;Vol.4,Issue73,September10;Page:12668-12675,DOI:10.14260/jemds/2015/1826

ABSTRACT: AIM: All pregnant women are screened for gestational diabetes mellitus during pregnancy with timely intervention to reduce perinatal morbidity and obstetrics complication. OBJECTIVES: To determine the proportion of diabetes in ANC mother attending ANC OPD at Bharati Hospital, to evaluate the high risk factor causing abnormal GTT and to evaluate outcome of pregnant mother with GDM. METHODS/STUDY DESIGN: The prospective study was conducted in 100 pregnant women attending antenatal checkup who had no previous history of diabetes. ANC mothers were given 75gm glucose irrespective of last meal. A venous sample was collected at 2hr for estimating plasma glucose. Gestational Diabetes Mellitus was diagnosed if 2hrs.plasma glucose levels came >140mg/dl. RESULT AND CONCLUSION:The screening of pregnant woman for diabetes on their first visit to antenatal clinic can be an effective method in detection of diabetes during pregnancy. Though the higher incidence is found in the risk group women in comparison to non-risk group, universal screening can be recommended instead of selective screening. Early screening does help in early detection of diabetes. Chances of gestationaldiabetesareincreasingwithincreaseinagegravidity.Increasingmaternalcarbohydrateintoleranceinpregnantwomenisassociatedwithagradedincreaseinadversematernalandfetaloutcome.WomendiagnosedtohaveGDMareatincreasedriskoffuturediabetespredominantlytype2DMasaretheirchildren.ThusGDMoffersanimportantopportunityforthedevelopment,testingandimplementationofclinicalstrategiesfordiabetespreventionandreducingperinatalmorbidityandobstetricscomplications.

INTRODUCTION:Pregnancyinducesprogressivechangesinmaternalcarbohydratemetabolism.Aspregnancyadvancesinsulinresistanceanddiabetogenicstressduetoplacentalhormonesnecessitatecompensatoryincreaseininsulinsecretion.Whenthiscompensationisinadequategestationaldiabetesdevelops.Gestationaldiabetesmightbetterbetermedas"Glucoseintoleranceduringpregnancy.GestationalDiabetesMellitusisdefinedascarbohydrateintolerancewiththeonsetorfirstrecognizedduringpregnancywithorwithoutremissionaftertheendofpregnancy."TheimportanceofGestationaldiabetesmellitus(GDM)isthattwogenerationsareatriskofdevelopingdiabetesinthefuture.WomenwithahistoryofGDMareatincreasedriskoffuturediabetes,predominatedtype2diabetesasaretheirchildren.Besidesanyabnormalglucoseintoleranceduringpregnancyalsohasadversefetaloutcome.

AllcomplicationassociatedwithGDMarepotentiallypreventablewithearlyrecognitionofGDM,intensemonitoringandpropertreatment.Moreover,inviewofthehighprevalenceofdiabetesMellitusanditsearlyonsetamongIndians,allpregnantwomenshouldbescreenedforGDM.HenceanappropriatescreeningforGDMhasbeenmuchemphasized.Detectingtheevidenceofdiabetesmellitusinpregnancyisamajorchallengeastheconditionisassociatedwithdiverserangeofadversematernalandneonataloutcomes.

InIndianscenario,screeningisessentialinallpregnantwomenasIndianshave11-foldincreasedriskofdevelopingglucoseintoleranceduringpregnancyascomparedwithCaucasianwomen.[1]Recentdatasuggests16.55%prevalenceofGDMinourcountry,[2]henceuniversalscreeningduringpregnancyhasbecomeimportantinourcountry.

AIMSOBJECTIVES:

AIMS: AllpregnantwomenarescreenedforGestationalDiabetesMellitusduringpregnancywithtimelyinterventiontoreduceprenatalmorbidityandobstetricscomplication.

OBJECTIVES:

TodeterminetheproportionofdiabetesinANCmotherattendingANCOPD.
ToevaluatethehighriskfactorcausingabnormalGTT.
ToevaluatethecomplicationofpregnantmotherwithGDMandperinataloutcome.

MATERIALSANDMETHODS: Thestudywasahospitalbasedprospectiveanalyticalstudy.Thepresentstudywasconductedin100pregnantwomenpresentedforAntenatalcheckupindepartmentofObstetricsandGynecology,BharatiVidyapeethDeemedUniversityMedicalCollegeHospitallocatedatWanlesswadi,Sangli,Maharashtra.ThepregnantwomenvisitingANCclinicbetween24-28Week’sgestationandwhohavenohistoryofdiabetesdiagnosedbeforepregnancywereselectedforthepresenthistory.Thestudyperiodwas1stJan2013to31stDec.2013.Onehundredpregnantwomenwerescreenedandweregroupedintwogroupsaccordingtopresenceorabsenceoftheriskfactors.Historicalriskfactorsconsideredwere,familyhistoryofdiabetes,previousmalformedbaby,badobstetrichistorylike,previousunexplainedstillbirth,recurrentabortionspreviousbigbabyandprevioushistoryofIUD.RiskfactorstakenintoaccountwereHydramnios,Suspectedbigbaby,GlycosuriaandObesity.

ExclusionCriteria:

DiabetesMellitusdiagnosedbeforepregnancy.
Historyofintakeofdrugsthataffectglucosemetabolismlikecorticosteroids.

Procedure:"ANCmotheratBharatiHospitalwithwrittenconsent,weregivena75gmoralglucoseload,irrespectiveofwhethershewasinthefastingornon-fastingstatewithoutregardtothetimeofthelastmeal.Avenousbloodsamplewascollectedat2hr forestimatingplasmaglucose.GDMwasdiagnosedif2hoursplasmaglucosewas>140mg/dl.EachandeverypatientwhohadpositiveGCTwereundergoneOGTT.ThistestneedsconfirmationbyadiagnosticandconfirmatoryoralglucosetolerancetestandformsapartoftwosteptechniqueforGDMScreening.Thesepregnantwomenwereprospectivelyfollowedformaternalcomplicationandperinataloutcome.

RESULTSDISCUSSIONS: ScreeningDiagnosis:

WHOProcedure: Whenaglucosetolerancetestisadministeredtoanon-pregnantindividual,itisstandardtousethe75-g,2-hourOGTT.Usingadifferentglucosechallengeinpregnantversusnon-pregnantpersonsleadstoconfusioninthelaboratoryandmayresultinerrorsinapplyingtheproperdiagnosticcriteria.[3]TostandardizethediagnosisofGDM,theWorldHealthOrganization(WHO)recommendsusinga2hour75gm OGTTwithathresholdplasmaglucoseconcentrationofgreaterthan140mg/dlat2hours,similartothatofIGT(>140<199mg/dl),outsidepregnancy.[4]

WHOprocedurealsohasashortcominginthat,thecriteriasuggestedfordiagnosisofGDMwasalsonotbasedonthematernalandfetaloutcomebutprobablythecriteriawasrecommendedforitseasyadaptabilityinclinicalpractice.

Age inYears / Cases
Screened / GCTPositive / OGTTPositive
No. / % / No. / %
<20 / 29 / 4 / 13.79 / 0 / 0.00
20-30 / 67 / 15 / 22.38 / 2 / 2.98
>30 / 4 / 2 / 50.0 / 1 / 25.0
Table 1: Case Distribution According to Maternal Age

NowinWHOprocedure,intheantenatalclinic,apregnantwomanafterundergoingpreliminaryclinicalexamination,hastobegivena75goralglucoseload,withoutregardtothetimeofthelastmeal.GDMisdiagnosedif2hr plasmaglucoseis≥140mg/dl.

Gravida / No.ofCase / PositiveGCTCase / PositiveOGTTCase
No. / % / No. / %
1 / 13 / 2 / 15.38 / 0 / 0.0
2 / 51 / 10 / 19.60 / 0 / 0.0
3 / 22 / 4 / 18.18 / 1 / 4.54
4 / 7 / 2 / 28.57 / 0 / 0.0
5 / 5 / 2 / 40.0 / 1 / 20.0
6andabove / 2 / 1 / 50.0 / 1 / 50.0
Table 2: Distribution According to Gravidity

MaternalAge: Thistableshowsthecasedistributionaccordingtomaternalage.Itisclearfromthetablethatincidencewashigherinthehigheragegroup.Severalauthorshavereportedincreasingfrequencyofgestationaldiabeteswithincreasingage(O’SullivanJ.etal.,MestmanJ.etal.,MerkatzI.etal.)InAmankwah’sstudy(1974),[5]67.6%ofdiabeticswereatorabove25yearsofage.Pyke(1971).[6]provedthatcarbohydratetolerancedeterioratesprogressivelywithage,especiallyinwomen.

Gravidity: Thistableshowsgraviditydistributioninthescreenedpopulation.IncidenceofpositiveGCTwasfoundtobeincreasingwithincreasinggravidity.Itwaslowestinprimigravidae.PercentageofpositiveOGTTwasalsofoundtobehigherinmultigravidawomen.Ithasbeenreportedthatincreasingparityleadstoagreaterlikelihoodofdiabetesdevelopinginlaterlife(Pyke1956),[7]andinthissense,pregnancyhasbeenstatedtobediabetogenic.Asshownintable,incidenceofdiabeteswashigherinthosewithhighergravidity.OurfindingscorrelatewiththefindingofaffafMohemmedetal.(1989),[8]whoalsohavenoticedthesame.

Cases / GCTPositive / OGTTPositive
No. / % / No. / % / No. / %
Obese / 3 / 3 / 2 / 66.6 % / 1 / 33.3 %
Non-obese / 97 / 97 / 19 / 19.5 % / 2 / 2.06 %
Table 3: Distribution of Cases According to Presence of Obesity

Obesity: ThisTableshowsthedistributionofcasesaccordingtopresenceorabsenceofobesity.Broch’sformulawasusedtodefineobesity.Thosewomenwithweightmorethan120percentoftheiridealweightwereconsideredtobeobese.[9]Outof100pregnantwomen,only3wereobesei.e.3%oftotalpopulation.Thismaybeexplainedonthebasisofpoorsocioeconomicclassofthescreenedwomen.Outofthese3,2womenshowedpositiveGCTandonewasdiabetic.Thustheincidenceofdiabeteswasquitehigher(33.3%)inobesegroupascomparedtononobese(2.06%).SimilarresultswereobtainedbyAffafMohemmedetal.(1989).[8]whonoticedhigherincidenceinthoseweighingmorethan70kgascomparedtothoselessthan70kg.

Group / Number of Cases / Percentage
Group-I (Withrisk) / 35 / 35%
Group–II(Non-risk) / 65 / 65%
Total / 100 / 100 %
Table 4: Distribution According to Risk Factor

DISTRIBUTIONACCORDINGTORISKFACTOR: Thistableshowsthatthirtyfivepregnantwomenwerehavingoneormoreriskfactorsandsixtyfivewomenhadnoriskfactori.e.35%oftotalpopulationhadariskfactor.MalhotraS.etal.(1988).[10]havereportedonepregnantwomaninevery2.5,whileGilmerM.etal.(1980).[9]havereportedoneinevery3pregnantwomenhadriskfactor.ChenW.etal.(1972).[11]havereportedonewomenwithriskfactorinevery6pregnantwomen.

Risk Factor (n = 35) / No. of Cases / %
1. FamilyH/oDiabetes / 1 / 2.85%
2.PreviousUnexplainedStillbirth,RecurrentAbortion / 10 / 28.57%
3.H/oPreviousMalformedBaby / 1 / 2.85%
4.PreviousBigBaby / 3 / 8.57%
5.PreviousH/oIUD / 2 / 5.71%
Table 5: Prevalence of Risk Factors in History

PrevalanceofRiskFactorinHistory: Outofvarioushistoricalriskfactors,previousunexplainedstillbirth,neonataldeath,recurrentabortionswerepresentin28.57%ofriskgroup35pregnantwomen.Pasthistoryofbigbabyis8.57%andpreviousH/oIUDwerepresentin5.71%pregnantwomen.Familyhistoryofdiabeteswaspresentin2.85%ofsuchpregnantwomen andpasthistoryofmalformedbabywaspresentin2.85%ofsuchpregnantwomen.

Risk Factor( n=35) / No. of Cases / Percentage
Hydramnios / 3 / 8.57%
Glycosuria / 10 / 28.57%
SuspectedBigBaby / 2 / 5.71%
Obesity / 3 / 8.57%
Table 6: Prevalence of Risk Factor

Prevalance ofRiskFactor: Thistableshowsprevalenceofriskfactorsingrouponei.e.withriskgroup(n=35).Glycosuriawaspresentin10(28.57%)pregnantwomen.10(28.57%)womenhadunexplainedstillbirthandrecurrentabortions.Threewomenwereobese.3(8.5%womenhadhistoryofpreviousbigbabywhile2(5.71%)werehavingsuspectedbigbabyinthispregnancy.3(8.5%)women,out35hadhydramnios.Historyofpreviousmalformedbabywasthereinone(2.85%)pregnantwomanand1(2.85%)hadfamilyhistoryofdiabetes.Noneofthemhaddiagnosedgestationaldiabetesintheirpreviouspregnancy.

Group / Positive GCT Cases / Positive OGTT Cases
No. / % / No. / %
GroupI(Risk)(n=35Cases) / 8 / 22.8% / 2 / 5.7%
GroupII(Non-risk)
(n=65Cases) / 13 / 20.0% / 1 / 1.5%
Total(100 Cases) / 21 / 21.0 % / 3 / 3.0 %
Table 7: Incidence of Diabetes in Two Different Groups

IncidenceofDiabetes: ThistableshowsthepatientswithriskfactorhadthefrequencyofOGTT5.71%ascomparedto1.5%inpatientswithoutriskfactor.IngroupI,outof35cases,8caseshadGCTpositiveandoutofthemtwowashavingabnormalOGTT.IngroupII,outof65cases,13hadpositiveGCTwhile0neofthemprovedtobediabeticinsubsequentOGTT.Variousauthorshavereporteddifferentpercentageofincidencesofdiabetesinriskgroupandnon-riskgroup.OurresultsinrespectofpregnantwomenwithriskfactorismoreorlesssimilartothoseofMalhotraS.etal.(1988).[10]Theyhavefound3.7%frequencyofOGTT+veinpregnantwomenwithriskfactors.Withregardtoresultsinrespectofpregnantwomenwithoutriskfactor,itismoreorlesssimilartothoseLavinJ.etal.(1981),[12]whichtheyhavefoundfrequencytobeat1.4%.Thefindingsofcurrentstudyaswellasthoseofpreviousstudiesindicatethatifthepregnantpopulationisscreenedonlyonthebasisofriskfactors,asignificantnumberofwomenwithgestationaldiabetesandtheiroffspringswillbedeniedthebenefitsofthisimprovedcare.

Timing: AsperCanadianDiabetesAssociation-2008guidelinerecommendation,screeningofallpregnantwomenshouldbebetween24-28weeksusingGCT.AsperWHOcurrentrecommendation,thescreeningtestshouldbeperformedbetween24and28weeksofgestation,thoughtherearereportsthatclaimabout40%to66%ofwomenwithGDMcanbedetectedearlyduringpregnancy.[13],[14]

AnalysisofScreeningTestResults:

Plasma GlucoseMg/dl / Number of Cases
Upto-119 / 32
120–129 / 37
130–139 / 10
140–149 / 12
150andmore / 9
Table 8: Distribution of Screened Population at Different Zones of Plasma Glucose Level

PlasmaGlucoseLevel: Thistableshowsthedistributionofscreenedpopulationindifferentzonesofplasmaglucoselevel.Maximumnumberofwomenwashavingtheirscreeningtestvalueinthezoneof120to129mg/dl.38womenhadthevalueinthezoneof119mg/dlandbelow,whowerenottestedfurtherwithOGTT.51hadtheirscreeningtestvalueinthezoneof120to139mg/dlandthesewerealsonotscreenedfurtherbecausethecutoffpointinourstudywasdecidedtobe140mg/dlofplasmaglucose.Wefound21women,whohadtheirscreeningtestvalue140mg/dlaboveandthesewere

Plasma GlucoseMg/dl / No. of GCT / No. of OGTT / %
140–149 / 12 / 1 / 8.33
150andabove / 9 / 2 / 22.2
Table 9: Corelation of Positive GCT With Positive OGTT at Different Zones of Plasma Glucose Level

CORELATIONTOFGCT+WITHOGTT+:ThistableshowsthecorrelationofpositiveGCTandpositiveOGTTatdifferentzonesofplasmaglucoselevel.Wefound1(8.33%)diabeticwoman(positiveOGTT)outof12womeninthezoneof140-149mg/dl.Inthezoneof150mg/dlandabove,therewere09womenwithpositiveGCT,outofthem2hadpositiveOGTTi.e.incidencewas16.66%.Thus,asthevalueofGCTincreased,thechancesofgettingpositiveOGTTwerealsoincreased.

Author / Threshold of Plasma Glucose
O’SullivanJ.etal. / 150mg/dl
AmankwahK.etal. / 130mg/dl
CarpenterM.etal. / 135mg/dl
GillmerM.etal. / 140mg/dl
LavinJ.etal. / 150mg/dl
MalhotraS.etal. / 150mg/dl
OurStudy / 140mg/dl

Variousauthorshaveusedvariousthresholdsforscreeningtest.SoitisclearfromourstudythatdecreasingthethresholdthoughincreasesthenumberofOGTT,itincreasestheyieldofpositivecasesandthusincreasesthesensitivityofthetest.

MaternalComplicationPerinatalOutcome:

Risk Factor / No. of Cases / Percentage
Macrosomia / 8 / 22.85%
CongenitalAnomolies / 7 / 20.0%
Hyperbilirubinemia. / 6 / 17.14%
RDS / 2 / 5.71%
Hypoglycemia, / 1 / 2.85%
hypocalcaemia, / 1 / 2.85%
Table 10: Distribution According to Perinatal Outcome
Risk / No. of Case / Percentage
PIH / 10 / 28.57%
pretermdelivery / 2 / 5.71%
Shoulderdystocia / 1 / 2.85%
PostpartumHemorrhage / 1 / 2.85%
Table 11: Distribution According to Maternal Complication

Theabovetablesinourstudyrevealed28.57%incidenceofPIH,22.85%incidenceofmacrosomia,20%incidenceofcongenitalanomaly,and5.71%incidenceofpretermlaborinGDMcases.Inourstudymacrosomiawasobservedin22.85%newbornsofGDMmothers.

SUMMARY: Onehundredrandomlyselectedpregnantwomenwerescreenedwith75gmsGCTfordetectionofdiabetesduringpregnancy,irrespectiveoftheirlastmeal.140mg/dlofplasmaglucosewasconsideredtobethecutoffpointforthetest.35%ofwomenhadoneormoreriskfactorfordiabetesandamongstallriskfactors,glycosuriaPIHwerehavingmaximumfrequencyi.e.28.57%eachofthehighriskpopulation.AnabnormalGCTwasfoundin21(21%)pregnantwomenand3(3%)womenweredetectedtobediabetic,whenfurthertestedwith75gms2hoursOGTT.Theincidenceofdiabetesinourstudypopulationwas3.0%onaverage.Itwas5.7%inhighriskgroupand1.5%innon-riskgroup.Maximumdetectionratewasfoundintheperiodof24to28weeksofgestation.Withtheincreaseinageandgravidity,chancesofgettingpositiveGCTandOGTTwerefoundtobeincreased.TherewashigherincidenceofabnormalGCTandOGTTinobesewomencomparedtonon-obese.ChancesofgettinganabnormalOGTTwerefoundtobeincreasedasthescreeningtestvaluewentinthehigherzoneofplasmaglucoselevel.ThereishigherincidenceofmaternalcomplicationofPIHasriskfactorinthehighriskgroupcases.Indistributionofperinataloutcome,thereishigherincidenceofMacrosomiahaving8cases(22.8%).

CONCLUSION: Screeningofallpregnantwomenfordiabetesduringtheperiod24to28weekscanbeaneffectivemethodindetectionofdiabetesduringpregnancy.IncidenceofGCTOGTTismoreinriskgroup.Thoughthehigherincidenceisfoundintheriskgroupwomenincomparisontononriskgroup,universalscreeningcanberecommendedinsteadofselectivescreening.IncidenceofGDMishigherinthehigheragegroup.Incidenceofdiabetesisprogressivelyhigherinthemultigravidas.Incidenceofdiabetesisquitehigherintheobesity.IncidenceofpositiveOGTTwerefoundtobeincreasedasthescreeningtestvaluewentinthehigherzoneofplasmaglucoselevel.Earlyscreeningdoeshelpinearlydetectionofdiabetes.GDMisassociatedwithavarietyofmaternalcomplicationandfetaloutcome.Thedetectioncouldbehelpfultodiagnoseandsubsequentlymonitor,duringANCperiod,andpromptinterventionscanpreventmaternalcomplicationsandimproveperinataloutcome.

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