1. Physiological changes
        1. Heart displaced upward and to the left.
        2. Circulation:
          1. Cardiac volume increases by 20-30%.
          2. Labor - cardiac output increases by 20-30%.
        3. Hemoglobin and hematocrit values remain between 10-14 g and 35-42%, normal drop is 10% during second trimester.
        4. Hypercoagulability - increased levels of blood factors VII, VIII, IX, and X.
        5. Nonpathologic increased sedimentation rate - due to 50% increase in fibrinogen level.
        6. Blood pressure should remain stable with drop in second trimester.
        7. Heart rate often increases 10-15 beats/min at term.
        8. Compression of pelvic veins —> stasis of blood in lower extremities.
        9. Compression of inferior vena cava when supine —> bradycardia —> reduced cardiac output, faintness, sweating, nausea (supine hypotension). Fetal response: marked bradycardia due to hypoxia secondary to decreased placental perfusion.
      2. Assessment:
        1. Apical systolic murmur.
        2. Exaggerated splitting of first heart sound.
        3. Physiologic anemia.
        4. Dependent edema in third trimester (Table 4-6).
        5. Vena cava syndrome (supine hypotension) - drop in systolic blood pressure may occur due to compression of descending aorta and inferior vena cava when supine.
        6. Varicosities (vulvar, anal, leg).
      3. Nursing care plan/implementation:
        4. Goal: health teaching
        1. Elevate lower extremities frequently.
        2. Apply support hose.
        3. Avoid excess intake of sodium.
        4. Assume side-lying position at rest.
        5. Learn signs and symptoms of pregnancy-induced hypertension.

    1. Respiratory system
      1. Physiological changes:
        1. Increased tidal volume, vital capacity, respiratory reserve, oxygen consumption, production of CO2.
        2. Diaphragm elevated, increased substernal angle —> flaring of rib cage.
        3. Uterine enlargement prevents maximum lung expansion in third trimester.
      2. Assessment:
        1. Shortness of breath or dyspnea on exertion and when lying flat in third trimester.
        2. Nasal stuffiness due to estrogen-induced edema (see Table 4-6).
        3. Deeper respiratory excursion.
      3. Nursing care plan/implementation:
        4. Goal: health teaching
        1. Sit and stand with good posture.
        2. When resting assume semi-Fowler’s position.
        3. Avoid overdistention of stomach.

  1. Alterations affecting elimination
    1. Urinary system
      1. Physiological changes:
        1. Relaxation of smooth muscle results in conditions that can persist 4-6 wk after birth:
          1. Dilatation of ureters.
          2. Decreased bladder tone.
          3. Increased potential for urinary stasis and infection (UTI).
        2. Increased glomerular filtration rate (50%) during last two trimesters.
        3. Increased renal plasma flow (25-50%) during first two trimesters; returns to near normal levels by end of last trimester.
        4. Increased renal-tubular reabsorption rate - compensates for increased glomerular activity.
        5. Glycosuria - reflects kidney’s inability to reabsorb all glucose filtered by glomeruli (may be normal or may indicate gestational diabetes; glycosuria always warrants further testing).
        6. Increased renal clearance of urea and creatinine (creatinine clearance used as test of renal function during pregnancy).
        7. Hormone - induced turgescence of bladder and pressure on bladder from gravid uterus (see Table 4-6).
      2. Assessment:
        1. Urinary frequency, first and third trimesters (see Table 4-6).
        2. Nocturia.
        3. Stress incontinence in third trimester.
      3. Nursing care plan/implementation:
        4. Goal: health teaching
        1. Void with urge, to prevent bladder distention.
        2. Learn signs and symptoms of UTI.
        3. Decrease fluid intake in late evening.
        4. Perform Kegel exercises to reduce incontinence.