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1、Chapter4:Prenataldevelopment,birth,andnewborns’readinessforlife.Dr.PelaezFromconceptiontobirthPrenataldevelopmentisdividedinto3majorphases:GerminalperiodEmbryonicperiodFetalperiodGerminalPeriodFromconceptiontoimplantation(about14days).ZygotemovestowarduterusthroughfallopiantubeImplantationoccur
2、sSupportsystemdevelops(4structures)EmbryonicperiodLastsfromweek3toweek8.Neuraltubedevelopmentbegins.HeartbeginstobeatGrowsabout1/30inchesperday.Externalbodystructuresform(ears,limbs,eyes)FetalperiodLastsfromweek9toterm.Byendofmonth3,sexcanbedetectedonultrasoundNeuralandmuscularsystemscontinueto
3、developBysecondtrimester(month5-6),coveredbyvernix&lanugo(substancethatprotectsfetalskin&finehairwhichhelpsvernixtosticktobody).Thirdtrimester(weeks25-38)involverapidgrowthandmaturityofallorgansystems.TeratogensExternalagentssuchasviruses,drugs,andradiationthatcanbeharmfultodevelopingembryoorfe
4、tus.SensitiveperiodsLong-termeffectsdependonthequalityofpostnatalenvironmentMaternaldiseasesDiseasescapableofpassingthroughplacentaanddamageembryo/fetusRubella.60-85%ofbabiesexposedwillhavebirthdefects.STD’s(AIDS,herpes,syphilis).ToxoplasmosisInfluenzaMalariaTuberculosisDrugsDrugstakenbymotherc
5、anhaveharmfuleffectsonchildren:(lowbirthweight,heartdefects,brain&neurologicaldefects,anddeath).ThalidomideDiethylstilbestrol(DES)AlcoholCigarettesIllegal,prescription,andoverthecounterdrugsEnvironmentalhazardsEnvironmentalhazardsthatmaycauselowbirthweight,miscarriages,orgeneticdefectstoembryo/
6、fetus:RadiationLeadZincMercuryOtherharshchemicalsMaternalcharacteristicsMaternalbehaviorcanaffecttheoutcomeofherpregnancyMother’sdietMother’semotionalwell-beingMother’sageBirthProcessPerinatalenvironment:environmentsurroundingbirth;includesinfluencessuchasdrugsgiventothemother,deliverypractices
7、,andthesocialenvironment.3stageprocess:1.firststageoflabor:uterinecontractions.Lastsabout3-8hours.2.secondstageoflabor:fetusmovesthroughbirthcanal&emergesfrommother’sbody.3.thirdstageoflabor:expulsionoftheplacentaThreestagesofchil