Medical considerations of the pregnancy in dental treatment

1. Medical considerations of the pregnancy in dental treatment Reporter : 碩一 吳和泰 Supervisor : 雷文天 大夫 高壽延 主任

2. Maternal concerns • Fetal concerns • Radiography • Medication • Summary

3. Maternal concerns • Fetal concerns • Radiography • Medication • Summary

4. Maternal concerns • Anatomic change • Physiology changes • Psychological changes

5. Anatomic changes • Uterus weight from 70gm 1 kg • Uterus volume from 10ml 5000 ml • Supine hypotensive syndrome Acute hypotensive episode

6. Supine hypotensive syndrome • Third trimeter 10~15% • Compression of inferior vena cava & aorta • Decrease venous return to heart • Decrease uteroplacental perfusion and fetal distress

7. Prevention • Left lateral decubitus position • Elevation the right hip 10~12cm • Sit up position

8. Physiologic changes • Cardiovascular system • Respiratory system • Gastrointestinal system • Renal system • Hematological system

9. Cardiovascular system • Cardiac outputincrease 40% • Mean arterial BP decrease • Total blood volume increase 40~50% (1500ml) • 14th to 30th weeks heart rate increase 10 beats/min

10. Respiratory system • Diaphragm is displaced upward 3~4cm & rib flare out with chest circumference of 5~7 cm • Oxygen consumption increase 15~20 % • Respiratory rate increase

11. Gastrointestinal system • Increase gastric acid production • Decrease gastric mobility • Incompetence of gastroesophageal sphincter • Esophageal reflux • Pernicious vomiting • Constipation

12. Renal system • Increase GFR • Increase renal plasma flow • Urinary tract infection

13. Hematological system • Plasma volume increase 40~70c.c./kg • Red cell volume increase 25-30c.c./kg • Hemoglobin & hematocrit volume decrease • Plasma levels of factors VII, VIII, X and fibrinogen increase • Fibrinolytic activity decrease

14. Psychological changes • Hypersensitivity regarding her size & appearance • Fear of pain, disability, death and for baby • Fear of dental procedures • Sedation empathy and reassurance • Minimize disturbance interruption & noises & to adjust room temperature & to minimize possible irritability

15. Maternal concerns • Fetal concerns • Radiography • Medication • Summary

16. Fetal concern • Fetal development • Ovum- from fertilization to implantation period • Embryonic period- from the second through eighth week • Fetal period- after the eighth week until term

17. Ovum period • Conception(受孕) to 17 days • Cellular mitotic activity • Sensitivity to toxic substances which may precipitate spontaneous abortion

18. Embryonic period • 18-55 days (2nd~8th wk) • Organogenesis • Functional & morphologic malformation

19. Fetal period • 56 days until parturition • Growth & development

20. The First Trimester (0-12 Weeks) • The Second Trimester (13-28 Weeks) • The Third Trimester (29-40 Weeks) The Second Trimester

21. First trimester • Most of the baby structure begin to develop • Most susceptible to the risks of physical and mental abnormalities • 50% of abortion • 5~7 wks in uterus cleft in lips & palate

22. Fetal concerns • Avoidance of fetal hypoxia • Avoidance of premature abortion • Avoidance of teratogens

23. Avoidance of fetal hypoxia • Uteroplacental blood flow & maternal oxygenation • Hgb = 17gm/dl enhanced ability to extract oxygen from maternal circulation • Maternal hypoxia from hypoventilation or hypotention

24. Avoidance of premature abortion • Site of position • No relationship between premature labor(分娩) & local anesthesia • G.A.  increase of fetal loss

25. Avoidance of teratogens • Before implantation (14days) death of the ovum • 14-60 days major morphologic defects (organogenesis) • 60 days later function impairment (reduce intellect)

26. Maternal concerns • Fetal concerns • Radiography • Medication • Summary

27. Radiography • High dose (over 250rads) prior to 16 wks • Microcephaly • Mental retardation • Cataracts (白內障) • Microphthalamia • Growth retardation • Spontaneous abortion • High dose after 20 wks • Hair loss • Skin lesions • Bone marrow suppression

28. Hazard from irradiation of embryo • Death of embryo • Birth of a deformed child • Increase frequency of malignancy decrease in childhood e.g. leukemia

29. Hazard from irradiation of embryo • 1 rad of utero radiation exposure has been estimated to be approximately 0.1% malignant disease • A dental periapical film 0.00001 rad (0.1 mrad) • Naturally occurring 1/2000

30. Radiography An 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.

31. Procedure in making radiographs for pregnancy patients • Make only the film absolutely essential for diagnosing the conditions • Use lead-shielding • Use long cone • Use proper collimation & shielding • Limited to affected tooth • Extra care should be used while taking essential films to eliminate the need for repeated exposure

32. Maternal concerns • Fetal concerns • Radiography • Medication • Summary

33. Medication • Local anesthesia • Antibiotics • Analgesics • Corticosteroids • Sedatives

34. Food and drug administration (F.D.A) classification system

35. Local anesthesia • Local 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.

36. Vasoconstrictors • Local vasoconstriction • Delay uptake from the site of injection • Increase the effectiveness & duration There is no specific contraindication to these vasoconstrictors in a pregnant patient although it is prudent to use minimal effective dose.

37. Local anesthesia • Convulsion in a sensitized mother could also exert a teratogenic effect second to hypoxia • The need for careful Hx taking & for aspiration & slow injected technique is obvious.

38. AntibioticsPenicillin • FDAB • All trimester are safe • No teratogenic • Pass the placenta • Inhibit cell wall synthesis

39. Tetracycline • Contraindication • Chelation with calcium & deposited in the skeleton of the fetus resulting in depression of bone growth • Discoloration • Maternal fatty liver degeneration • FDAD

40. Chloramphenicol • Bone marrow depression irreversible aplastic anemia agranulocytosis • FDAC • Gray-baby syndrome • Contraindication

41. Aminoglycoside • Ototoxicity • Nephrotoxity • FDAD

42. Analgesics • Identify the cause of the pain • Eliminate it rather than relying on symptomatic relief with analgesic medication

43. Acetaminophen • No teratogenesis • Most frequency used • Analgesic and antipyretic but no anti-inflammation activity

44. Aspirin • Oral clefts and other defects • Intrauterin death,growth retardation,pulmonary hypertention • Longer pregnancies & longer the average period of labor • Tetralogy of Fallot (Raot, RVhyperatrophy,Vsep def,Pula.steno) • Increase the risk of antepartum and postpartum hemorrhage.

45. NSAID • Contraindication • Inhibit synthesis of postaglandins. • Constrict the ductus arteriosus & persistent pulmonary hypertension & increase mortality

46. Corticosteroid • Cleft palate • Inhibit brain growth • Indicated only for treatment of severe systemic maternal illness (e.g. RA)

47. Sedative agents • Barbiturates • Anxiolytic agents • Inhalational sedative

48. Barbiturates • Cross the placental membrane • Chronic barbiturate use-withdrawal syndrome • Cleft palate-lip

49. Anxiolytic agents • Diazepam • Cleft lip and palate • Chronic diazepam user-tremors in infants • Accumulate in the tissue of fetus

50. Inhalation sedatives • Increase the rate of spontanous abortion in chronic exposed perons • Vit-B12cofactor of foliate metabolism • Foliate metabolism-thymidine formation (DNA base) • N2Ooxidase Vit-B12