A lecture for medical students detailing the physiologic changes that take place during pregnancy

13. The primary goal of prenatal care is to deliver a healthy term infant without impairing the mothers health and to identify and optimally treat the high-risk mother.

14. The vast majority of pregnancies are uncomplicated. Excessive intervention during pregnancy can result in less than optimal outcome

15. THE CARDIOVASCULAR SYSTEM:

17. CARDIAC OUTPUT DURING PREGNANCY

18. Peripheral vascular resistance falls Blood pressure falls during the second trimester and then returns to normal during the third trimester

19. CLINICAL SIGNIFICANCE: Many of the NORMAL effects of pregnancy mimic heart failure (edema, gallops, dyspnea, distended neck veins, abnormal cardiac silhouette on CXR, EKG changes).

20. THE RESPIRATORY SYSTEM:

21. Lung volumes changes in pregnancy

22. NO CHANGE: Respiratory rate, Vital capacity, Inspiratory reserve volume

23. DECREASED: Functional residual capacity Expiratory reserve volume Residual volume Total lung capacity

24. INCREASED: Inspiratory capacity Tidal volume

25. BLOOD GASES: CLINICAL SIGNIFICANCE: The normal pregnant woman has a compensated respiratory alkalosis and a diminished pulmonary reserve.

26. THE RENAL SYSTEM:

27. ANATOMIC RENAL CHANGES: Kidneys increase in size and weight, Dilatation of ureters (R > L) Bladder becomes an intra-abdominal organ

28. HEMODYNAMIC RENAL CHANGES: GFR increases 50%, Renal plasma flow increases by 75% Creatinine clearance increases to 150-200 cc/min

32. THE HEMATOLOGIC SYSTEM

33. Plasma volume and RBC mass Plasma volume increases by about 50% RBC volume increases by about 30%

34. Plasma volume and RBC mass END RESULT: ”Dilutional anemia of pregnancy", Average hemoglobin during pregnancy is 11.5 g/dl

35. Plasma volume and RBC mass

36. OTHER HEMATOLOGIC CHANGES: WBC count increases Platelet count decreases, but stays within normal limits

37. COAGULATION SYSTEM: Pregnancy is a "hypercoagulable state" Increased levels of fibrinogen, factor VII-X The placenta produces a plasminogen activator inhibitor

38. CLINICAL SIGNIFICANCE: Blood loss is well-tolerated during labor. However: maternal vital signs DO NOT change for blood loss of up to 1500 cc, Therefore: vital signs cannot be trusted as an indicator of blood loss.

39. THE GASTROINTESTINAL AND REPRODUCTIVE SYSTEMS

40. Gastrointestinal System Decreased motility, due to influence of progesterone Reduced gastric acid secretion

41. Gastrointestinal System CLINICAL SIGNIFICANCE: A pregnant woman is considered to have a full stomach even if she has had nothing to eat or drink for several hours. Peptic ulceration is rare during pregnancy.

42. Reproductive System Weight of the Uterus increases from 70 gm to 1100 gm Blood flow: increases to about 750 cc/min, or 10-15% of cardiac output

43. NUTRITIONAL CONSIDERATIONS DURING PREGNANCY

44. PREGNANCY WEIGHT GAIN BY ORGAN SYSTEM: Fetus: 7 pounds Placenta and amniotic fluid -- 3 pounds Blood volume-- 4 pounds Breasts-- 2 pounds Maternal fat-- 4 pounds ANTICIPATED TOTAL: 20 pounds

45. Average weight gain THERE IS NO SUCH THING AS “OPTIMAL” WEIGHT GAIN Normal BMI: 20 lbs Underweight BMI: 30 lbs Overweight BMI 16 lbs

46. Daily dietary requirements Calories: Increased 15% to ~ 2200 cal/day Protein: An additional 10 to 30 gm /day ~ 75 gm/day total Iron supplementation 30 to 60 mg per day

47. Calcium: 1200 mg needed per day, usually provided by a quart of milk per day or 2 Tums/day, Folate: supplement 200 to 400 mcg per day In women with a prior history of having a baby with a neural tube defect, supplementing with 4 mg per day (4000 mcg) has been shown to decrease the risk of a recurrence in the next pregnancy

48. The pregnant patient is best served by having a healthy balanced diet with iron and folate supplementation. Only rarely are other vitamin supplements necessary

49. PRENATAL CARE

50. The first prenatal visit Decide: Is this patient normal or high-risk?

52. COMMON COMPLAINTS OF PREGNANCY

53. Nausea and vomiting: usually dissipates by 15 weeks

54. Constipation: common throughout pregnancy

55. Heartburn: often worsens as pregnancy progresses

56. Vaginitis: treat only if symptomatic

57. Varicose veins: treat symptomatically

58. Headaches

59. Lower extremity edema is very common

60. Backache: Lordosis is common with change in the center of gravity

61. Faintness and light-headedness

62. Carpal tunnel syndrome

63. REVIEW QUESTIONS:

69. For More Information and Other Maternal-Fetal Lectures, Please Visit: http://maternalfetalmedicineblog.com http://onyeije.net/present http://preeclampsiaonline.net