临床专科知识讲解习题考试题tusduringregnancy_settingthestageformotherandinfant

Ironstatusduringpregnancy:settingthestageformotherand14infantTheresaOSchollABSTRACTPREVALENCEANDETIOLOGYOFANEMIAANDIRONDEFICIENCYINWOMENSupplementationwithironisgenerallyrecommendedduringpreg-nancytomeettheironneedsofbothmotherandfetus.Whendetectedearlyinpregnancy,irondeficiencyanemia(IDA)isassociatedwitha2-foldincreaseintheriskofpretermdelivery.Maternalanemiawhen diagnosed before midpregnancy is also associated with anincreasedriskofpretermbirth.ResultsofrecentrandomizedclinicaltrialsintheUnitedStatesandinNepalthatinvolvedearlysupple-mentation with iron showed some reduction in risk of low birthweightorpretermlowbirthweight,butnotpretermdelivery.Duringthe3rdtrimester,maternalanemiausuallyisnotassociatedwithincreasedriskofadversepregnancyoutcomesandmaybeanindi-catorofanexpandedmaternalplasmavolume.Highlevelsofhe-moglobin,hematocrit,andferritinareassociatedwithanincreasedriskoffetalgrowthrestriction,pretermdelivery,andpreeclampsia.While iron supplementation increases maternal iron status andstores,factorsthatunderlieadversepregnancyoutcomeareconsid-eredtoresultinthisassociation,notironsupplements.Ontheotherhand,ironsupplementsandincreasedironstoreshaverecentlybeenlinkedtomaternalcomplications(eg,gestationaldiabetes)andin-creasedoxidativestressduringpregnancy.Consequently,whileironsupplementationmayimprovepregnancyoutcomewhenthemotherisirondeficientitisalsopossiblethatprophylacticsupplementationmayincreaseriskwhenthemotherdoesnothaveirondeficiencyorIDA. Anemia and IDA are not synonymous, even among low-Irondeficiencyisthemostcommonlyrecognizednutritionaldeficitineitherthedevelopedorthedevelopingworld.Duringtheirreproductiveyearswomenareatriskofirondeficiencydueto blood loss from menstruation, in particular that 10% whosufferheavylosses(80mL/mo).Contraceptivepracticealsoplaysaparttheintrauterinedevicesincreasesmenstrualbloodlossby30%50%whileoralcontraceptiveshavetheoppositeeffect.Pregnancyisanotherfactor.Duringpregnancythereisasignificantincreaseintheamountofironrequiredtoincreasetheredcellmass,expandtheplasmavolumeandtoallowforthegrowthofthefetal-placentalunit.Finally,thereisdiet.Womenintheirreproductiveyearsoftenhaveadietaryironintakethatistoolowtooffsetlossesfrommenstruationandtheincreasedironrequirement for reproduction (1). Consequently, the overallprevalenceofirondeficiencyinnon-pregnantwomenofrepro-ductiveageintheUnitedStates,9%11%,ishigherthanatotheragesapartfrominfancy.TheprevalenceofIDAinthesameagegroupis2%5%.PrevalenceofirondeficiencyandIDAisin-creased 2-fold or more for those women who are minorities,belowthepovertylevelorwith12yofeducation.Riskisalsoincreasedwithparitynearly3-foldhigherforwomenwith23childrenandnearly4-foldgreaterforwomenwith4ormorechildren,thusimplicatingpregnancy(2).incomeminoritywomenintheirreproductiveyears.AmJClinNutr2005;81(suppl):1218S22S.Itisestimatedthat50%ofwomendonothaveadequateironstoresforpregnancy(1,3).Becausetheironrequiredforpreg-nancy(34mg/d)issubstantial,riskofirondeficiencyandIDAshouldincreasewithgestation.However,theprevalenceofane-miaandIDAinpregnantwomenfromtheUnitedStatesisnotKEY WORDSAnemia, iron deficiency, ferritin, oxidativestress,pretermdelivery,lowbirthweight,gestationaldiabetes,iron,supplementation,pregnancywelldefinedbutmustbesubstantial,particularlyamongthepoor.Duringpregnancy,anemiaincreases4-foldfromthe1sttothe3rd trimester in the low-income women monitored as part ofpregnancynutritionalsurveillancebytheCDC(3).IntheCam-den Study where the cohort is mostly minority, current data(20002004)suggestthattheprevalenceofanemiaincreasesINTRODUCTIONAnemia,asdeterminedbylowhemoglobinorhematocrit,iscommonamongwomenintheirreproductiveyearsinparticularif the women are poor, pregnant, and members of an ethnicminority.Untilrecently,itwasassumedthatanemiaduringpreg-nancyhadfewuntowardsequelae.Duringthepastfewyears,therelationbetweenanemiaearlyinpregnancyandanincreasedriskofpretermdeliveryhasbeensuggested.Likewise,therelationofadverse pregnancy outcomes with high hemoglobin and in-creasedironstoreshasbeendocumented.However,therisksandbenefits of prophylactic iron supplementation in pregnantwomenwhoarenotirondeficientremainsasourceofcontro-versy.1FromtheDepartmentofObstetricsandGynecology,TheUniversityofMedicineandDentistryofNewJersey-SOM,Stratford,NewJersey08084.2Presentedattheconference“WomenandMicronutrients:AddressingtheGapThroughouttheLifeCycle,”heldinNewYork,NY,June5,2004.3Supported by HD18269, HD38329, and ES07437 from the NationalInstitutesofHealth.4Address reprint requests and correspondence to Theresa O Scholl,UMDNJ-SOM,DepartmentofOb/Gyn,ScienceCenter,Suite390,Stratford,NJ08104.E-mail:schollumdnj.edu.1218SAmJClinNutr2005;81(suppl):1218S22S.PrintedinUSA.2005AmericanSocietyforClinicalNutrition MATERNAL ANEMIA AND HIGH HEMOGLOBIN1219Sless(5