Physiology of Pregnancy II

Question 1

Genital Tract

Answer 1

• Cessation of ovulation
• Maintenance of corpus luteum
• Increased vaginal vascularity and secretions
• Uterine enlargement

Question 2

Musculoskeletal

Answer 2

• Postural changes
• Compensatory of lumbar lordosis
• Pubic symphysis separation
• Mobilization of calcium stores
• Ionized calcium (Ca2+) concentration is constant throughout pregnancy.
• Physiologic hyperparathyroidism

*Increases calcium absorption from gut

*Decreases calcium renal losses

Question 3

Dermatologic

Answer 3

• Striae gravidarum
• Hyperpigmentation
• Angiomas

Question 4

Metabolic

Answer 4

• Normal weight gain (25-35 pounds), components of fetus, placenta, fluid, uterus, breasts, blood volume, extravascular fluid, maternal stores
• Increased water retention with drop in plasma osmolality
• Ingestion and utilization of protein and other substrates to be available for maternal protein synthesis
• Diabetogenic nature of pregnancy with increased insulin, increased tissue resistance to insulin, suppressed glucagon, and responses to estrogen, progesterone, human placental lactogen
• Increases in lipids and lipoproteins

Question 5

Hematologic

Answer 5

•Increased blood volume (45-50%) with increased red cell mass (33%), with physiologic anemia of pregnancy

• Meets the demands of the enlarged uterus with its greatly hypertrophied vascular system
• Protects the mother, and in turn the fetus, against the deleterious effects of impaired venous return in the supine and erect positions
• Safeguards the mother against the adverse effects of blood loss associated with parturition
• Large iron requirements surpass dietary intake
• Suppression of humoral and cellularly mediated immune responses
• Increase in coagulation factors and fibrinogen
• Increased concentrations of clotting factors (except factors XI and XIII)
• Increased plasma fibrinogen levels • Risk of thromboembolism

*Nonpregnant = 1.0

*During pregnancy = 1.8

*During the puerperium = 5.5

Question 6

Cardiovascular

Answer 6

• Increase in HR, inotropy, cardiac output (30-50%)
• Altered vascular reactivity with angiotensin II, prostaglandins, intracellular calcium, and endothelium derived factors
• Decrease in arterial BP

Question 7

Respiratory

Answer 7

• Increased tidal volume, minute ventilatory volume and minute O2 uptake, with decreased functional residual volume
• Increased respiratory effort with decreased PCO2 and physiologic dyspnea

Question 8

Renal

Answer 8

• GFR increases by 50% and increases in RPF with increased loss of nutrients
• Some glucosouria and proteinuria can be normal
• Right-sided hydroureter and hydronephrosis may occur
• Decreased bladder capacity with increased bladder and urethral pressure

Question 9

Gastrointestinal Tract

Answer 9

• Delayed gastric emptying times with possible heartburn, secondary to decreased sphincter tone and reflux
• Possible hemorrhoids from constipation and increased pressure in veins below uterus
• Alkaline phosphatase increases 2x and plasma albumin decreases
• Gallbladder sluggish with impaired contraction and high residual volume and possible cholestasis and pruritis from bile salts

Question 10

Endocrine

Answer 10

• Pituitary enlarges 35% with hyperplasia of lactotrophs
• Prolactin increases during pregnancy, 10X at term
• Thyroid – increased TBG and total T4 and T3, with decreasing free T4 and T3 during pregnancy, though within normal limits
• Increased PTH and decreased calcium
• Increased t1/2 of cortisol and initial decreased ACTH with later increased CRH and free cortisol
• Increased aldosterone, DOC, androstenedione and testosterone

Question 11

Signs of Normal Pregnancy that May Mimic Liver Disease

Answer 11

• Spider angiomata
• Palmar erythema
• Reduced serum albumin concentration
• Elevated serum alkaline phosphatase activity
• Elevated serum cholesterol concentration

Question 12

Signs and Symptoms of Normal Pregnancy that may Mimic Heart Disease

Answer 12