5Anatomic changes Uterus weight from 70gm 1 kg Uterus volume from 10ml 5000 mlSupine hypotensive syndromeAcute hypotensive episode
6Supine hypotensive syndrome Third trimeter 10~15%Compression of inferior vena cava & aortaDecrease venous return to heartDecrease uteroplacental perfusion and fetal distress
7Prevention Left lateral decubitus position Elevation the right hip 10~12cmSit up position
8Physiologic changes Cardiovascular system Respiratory system Gastrointestinal systemRenal systemHematological system
9Cardiovascular system Cardiac output increase 40%Mean arterial BP decreaseTotal blood volume increase 40~50% (1500ml)14th to 30th weeks heart rate increase 10 beats/min
10Respiratory systemDiaphragm is displaced upward 3~4cm & rib flare out with chest circumference of 5~7 cmOxygen consumption increase 15~20 %Respiratory rate increase
11Gastrointestinal system Increase gastric acid productionDecrease gastric mobilityIncompetence of gastroesophageal sphincterEsophageal refluxPernicious vomitingConstipation
12Renal system Increase GFR Increase renal plasma flow Urinary tract infection
13Hematological system Plasma volume increase 40~70c.c./kg Red cell volume increase 25-30c.c./kgHemoglobin & hematocrit volume decreasePlasma levels of factors VII, VIII, X and fibrinogen increaseFibrinolytic activity decrease
14Psychological changes Hypersensitivity regarding her size & appearanceFear of pain, disability, death and for babyFear of dental proceduresSedation empathy and reassuranceMinimize disturbance interruption & noises & to adjust room temperature & to minimize possible irritability
16Fetal concern Fetal development Ovum- from fertilization to implantation periodEmbryonic period- from the second through eighth weekFetal period- after the eighth week until term
17Ovum period Conception(受孕) to 17 days Cellular mitotic activity Sensitivity to toxic substances which may precipitate spontaneous abortion
18Embryonic period 18-55 days (2nd~8th wk) Organogenesis Functional & morphologic malformation
19Fetal period56 days until parturitionGrowth & development
20The Second Trimester (13-28 Weeks) The First Trimester (0-12 Weeks)The Second Trimester (13-28 Weeks)The Third Trimester (29-40 Weeks)
21First trimester Most of the baby structure begin to develop Most susceptible to the risks of physical and mental abnormalities50% of abortion5~7 wks in uterus cleft in lips & palate
22Fetal concerns Avoidance of fetal hypoxia Avoidance of premature abortionAvoidance of teratogens
23Avoidance of fetal hypoxia Uteroplacental blood flow & maternal oxygenationHgb = 17gm/dl enhanced ability to extract oxygen from maternal circulationMaternal hypoxia from hypoventilation or hypotention
24Avoidance of premature abortion Site of positionNo relationship between premature labor(分娩) & local anesthesiaG.A. increase of fetal loss
25Avoidance of teratogens Before implantation (14days) death of the ovum14-60 days major morphologic defects (organogenesis)60 days later function impairment (reduce intellect)
27Radiography High dose (over 250rads) prior to 16 wks MicrocephalyMental retardationCataracts (白內障)MicrophthalamiaGrowth retardationSpontaneous abortionHigh dose after 20 wksHair lossSkin lesionsBone marrow suppression
28Hazard from irradiation of embryo Death of embryoBirth of a deformed childIncrease frequency of malignancy decrease in childhood e.g. leukemia
29Hazard from irradiation of embryo 1 rad of utero radiation exposure has been estimated to be approximately 0.1% malignant diseaseA dental periapical film rad (0.1 mrad)Naturally occurring 1/2000
30RadiographyAn adverse fetal effects is unlikely to result from exposure to less than 5 rads with lead apron in place the female gonadal dose from a single periapical radiographs is about 0.1 mrad.
31Procedure in making radiographs for pregnancy patients Make only the film absolutely essential for diagnosing the conditionsUse lead-shieldingUse long coneUse proper collimation & shieldingLimited to affected toothExtra care should be used while taking essential films to eliminate the need for repeated exposure
33Medication Local anesthesia Antibiotics Analgesics Corticosteroids Sedatives
34Food and drug administration (F.D.A) classification system
35Local anesthesiaLocal anesthesia are not teratogenic, and may administered to pregnancy patient is usual clinical doses.Large dose of prilocaine are know to cause methemoglobinemia (變性血紅素血症) which could cause maternal & fetal hypoxia.
36Vasoconstrictors Local vasoconstriction Delay uptake from the site of injectionIncrease the effectiveness & durationThere is no specific contraindication to these vasoconstrictors in a pregnant patient although it is prudent to use minimal effective dose.
37Local anesthesiaConvulsion in a sensitized mother could also exert a teratogenic effect second to hypoxiaThe need for careful Hx taking & for aspiration & slow injected technique is obvious.
38Antibiotics Penicillin FDABAll trimester are safeNo teratogenicPass the placentaInhibit cell wall synthesis
39Tetracycline Contraindication Chelation with calcium & deposited in the skeleton of the fetus resulting in depression of bone growthDiscolorationMaternal fatty liver degenerationFDAD
42Analgesics Identify the cause of the pain Eliminate it rather than relying on symptomatic relief with analgesic medication
43Acetaminophen No teratogenesis Most frequency used Analgesic and antipyretic but no anti-inflammation activity
44Aspirin Oral clefts and other defects Intrauterin death,growth retardation,pulmonary hypertentionLonger pregnancies & longer the average period of laborTetralogy of Fallot (Raot, RVhyperatrophy,Vsep def,Pula.steno)Increase the risk of antepartum and postpartum hemorrhage.
45NSAID Contraindication Inhibit synthesis of postaglandins. Constrict the ductus arteriosus & persistent pulmonary hypertension & increase mortality
46Corticosteroid Cleft palate Inhibit brain growth Indicated only for treatment of severe systemic maternal illness (e.g. RA)