CHILDBEARING: PREGNANCY BY TRIMESTER

General overview: This review of the normal physiological and psychosocial changes occurring during each trimester of pregnancy provides essential components of the database for accurate nursing judgments and anticipatory guidance during the prenatal period. Complications of pregnancy are correlated with the trimester of common occurrence; relationships with other NCLEX categories of human function are described.

  1. General aspects of nursing care
    1. Assessment - based on nursing knowledge of the following:
      1. Biophysical and psychosocial aspects of conception and gestation.
      2. Parameters of normal pregnancy.
      3. Risk factors, signs, symptoms, and implications of deviations from normal patterns of maternal and fetal health.
    2. Analysis/nursing diagnosis:
      1. Knowledge deficit related to normal pregnancy-related alterations (physiological and emotional alterations/trimester).
      2. Pain related to normal physiological alterations in pregnancy.
      3. Altered elimination related to normal physiological changes during pregnancy (polyuria, constipation).
      4. Altered nutrition related to increased metabolic needs due to pregnancy.
      5. Impaired adjustment related to altered self-image; anticipated role change; resurgence of old, unresolved conflicts.
    3. Nursing care plan/implementation:
      1. Goal: emotional support.
        1. Encourage verbalization of feelings, fears, concerns.
        2. Validate normalcy of behavioral response to pregnancy.
      2. Goal: anticipatory guidance.
        1. Facilitate achievement of developmental tasks.
        2. Strengthen coping techniques for pregnancy, labor, birth. Suggest appropriate resources (preparation for childbirth classes).
      3. Goal: health teaching. Describe, explain, discuss:
        1. Normal physiological alterations during pregnancy.
        2. Common discomforts of pregnancy, management.
    4. Evaluation/outcome criteria:
      1. Woman takes an active, informed part in her pregnancy-related care.
      2. Woman copes effectively with common alterations associated with pregnancy (physiological, psychological, role change).
      3. Woman successfully carries an uneventful pregnancy to term.

  2. Biologic foundations of pregnancy
    1. Conception
      1. Egg - life span, approximately 24 hours after ovulation.
      2. Sperm - life span, approximately 72 hours after ejaculation into female reproductive tract.
      3. Conception (fertilization) - usually occurs 12-24 hours after ovulation, within fallopian tube.
      4. Implantation (nidation) - usually occurs within 7-9 days of conception, or about day 21-23 of a 28-day menstrual cycle.
      5. Ovum - period of conception until primary villi have appeared; usually about 12-14 days.
      6. Embryo - period from end of ovum stage until measurement reaches approximately 3 cm; 54-56 days.
      7. Fetus - period from end of embryo stage until birth.
        8. First Trimester
        1. Susceptible to teratogens
        2. Heart functions at 3-4 weeks
        3. Eye formation at 4-5 weeks
        4. Arm and leg buds at 4-5 weeks
        5. Recognizable face at 8 weeks
        6. Brain: rapid growth
        7. External genitalia at 8 weeks
        8. Placenta formed at 12 weeks
        9. Bone ossification at 12 weeks
        Second Trimester
        1. Less danger from teratogens after 12 weeks
        2. Facial features formed at 16 weeks
        3. Fetal heartbeat heard by 18 to 20 weeks with a fetoscope/doppler
        4. Quickening at 18-20 weeks
        5. Length: 10 inches, weight: 8-10 oz
        6. Vernix: present
        Third Trimester
        1. Iron stored
        2. Surfactant production begins in increasing amounts
        3. Size: 15 inches, 2-3 lb
        4. Calcium stored at 28-32 weeks
        5. Reflexes present at 28-32 weeks
        6. Subcutaneous fat deposits at 36 weeks
        7. Lanugo shedding at 38-40 weeks
        8. Average size: 18-22 inches, 7.5-8.5 lb at 38-40 weeks
    2. Anatomical and physiological modifications
      1. Bases of functional alterations
        1. Hormonal - the effects of estrogen and progesterone during pregnancy. Nursing implications provide the knowledge base for the following:
          1. Anticipatory guidance regarding normal maternal adaptations.
          2. Early identification of deviations from normal patterns.
        2. Mechanical - enlarging uterus —> displacement and pressure; increased weight of uterus and breasts —> changes in posture and pressure.
      2. Breasts - enlarged darkened areola; secrete colostrum.
      3. Reproductive organs
        1. Uterus
          1. Amenorrhea. Occasional spotting common, especially at time of first missed menstrual period.
          2. Increased vascularity adds to increase in size and softening of the lower uterine segment (Hegar’s sign).
          3. Growth is due to hypertrophy and hyperplasia of existing muscle cells and connective tissue.
          4. Fundal height measurement landmarks:

            Uterus

            Nonpregnant

            Pregnant (At Term)

            Length

            6.5 cm

            32 cm

            Width

            4 cm

            24 cm

            Depth

            2.5 cm

            22 cm

            Weight

            50 g

            1000 g
        2. Cervix
          1. Increased vascularity —> softening (Goodell’s sign) and deepened blue-purple coloration (Chadwick’s sign).
          2. Edema, hyperplasia, thickening of mucous lining, and increased mucus production; formation of mucus plug by end of second month.
          3. Becomes shorter, thicker, and more elastic.
        3. Vagina
          1. Hyperemia deepens color (Chadwick’s sign).
          2. Hypertrophy and hyperplasia thicken vaginal mucosa.
          3. Relaxation of connective tissue.
          4. pH acidic (4.0-6.0).
          5. Leukorrhea - nonirritating.
        4. Perineum
          1. Increases in size - hypertrophy of muscle cells, edema, and relaxation of elastic tissue.
          2. Deepened color - increased vascularization/hyperemia.
        5. Ovaries
          1. Ovum production ceases.
          2. Corpus luteum persists; produces hormones to weeks 10-12 until placenta “takes over.”

    3. Alterations affecting fluid-gas transport
      1. Cardiovascular system
        2. Component Prepregnant Pregnant Postpartum
        WBC 4,000-11,000 9,000-16,000 (25,000 - labor) 20,000-25,000 within 10-12 days of birth, then returns to normal
        RBC volume
        1600 ml
        1900 ml
        Prepregnant level of 1600 ml
        Plasma volume
        2400 ml
        3700 ml
        Prepregnant level of 2400 ml
        Het (PCV)
        37-47%
        32-42%
        At 72°, returns to prepregnant level of 37-47%
        Hgb (at sea level)
        12-16 g/dl
        10-14 g/dl
        At 72°, returns to prepregnant level of 12-16 g/dl
        Fibrinogen
        250 mg/dl
        400 mg/dl
        At 72°, returns to prepregnant level of 250 mg/dl
        *Postpartum values depend on factors of amount of blood loss, mobilization, and physiological edema (excretion of extravascular water). Normal blood loss for vaginal birth is 300-400 ml.

        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.
          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.
      2. 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.
          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.