What, in general, are the (2) changes that result in the increased Blood volume observed during pregnancy?
- Increased RBC Mass
- Increased ECF Vol.
What is the general pathway leading to Increased RBC mass?
Increased levels of human Chorionic Somatomammotropin & Prolactin triggers Erythropoiesis. This leads to increased RBC mass.
How is retention of H2O altered leading to Hypovolemia?
Several factors (Aldosterone, Estrogen, Prolactin, hPL, +) lead to increased Na+ & H2O retention. This leads to increased ECF Volume and thus increased Blood Volume.
What are the (8) general hematological changes during pregnancy?
- Increased Plasma Vol. & Hemodilution
- Increased Hb levels (but physiological anemia)
- Increased Coagulation factors (except factors XI, XIII, & ATIII)
- Hypercoagulable state
- Increased Iron absorption in gut
- Increased Iron binding capacity but Decreased S. Iron
- Decreased RBC count
- Decreased Fibrinolytic Activity
- Decreased Platelet Count
What are the important functions of pregancy-induced Hypervolemia?
- Meet metabolic/ Nutrient demands of;
- Enlarged uterus & hypertrophied vascular system
- Rapidly growing Fetus & Placenta
- Protection of the mother and (in turn) the fetus against effects of impaired venous return in the supine & erect positions
- Protection of the mother against blood loss during child birth
How does the Plasma Volume change during PostPartum?
- Decrease @ Delivery
- Increases again 2-5 days later
- 10-15% above baseline @ 3Weeks
- Return to Baseline @ 6Weeks
What does whole blood consist of?
Whole blood:
- Blood Plasma Plasma (55%)
- Formed Elements (45%)
Describe the general constituents of blood plasma
Blood Plasma;
- Water (91.5%)
- Plasma Proteins (7%)
- Other Solutes (1.5%)
Describe the function of Plasma proteins and the major ones mentioned here.
Plasma Proteins, in general, are important for;
- Contributing to blood viscosity
- Transportation (Hydrophobic moelcules, Calcium, etc)
- Regulation of Blood pH
General types;
- Albumins: Helps maintain osmotic Pressure
- Globulins: Ig’s are part of Immune System; a & B-globulins transport iron, lipids, and fat-soluble vitamins
- Fibrinogen: Role in Blood Clotting
Other Solutes consists of what general categories?
Other Solutes (1.5%);
- Electrolytes: Helps maintain osmotic pressure
- Nutrients (metabolic molecules)
- Gases (O2, CO2, N2)
- Reg. substances (Enzymes, hormones, vitamins, etc.)
- Waste products (Urea, uric acid, creatine, creatinine, bilirubin)
What are the types of Formed Elements discussed?
Formed Elements;
- Platelets
- Erythrocytes
- Leukocytes;
- Neutrophils
- Lymphocytes
- Monocytes
- Eosinophils
- Basophils
What is the change in Erythropoietin levels during pregnancy?
Erythropoietin levels increase by 50%
Describe the change in Erythrocytes during pregnancy.
Erythrocytes levels increase by 20-30% (250-450ml) w/ iron-supplemented during pregnancy (15-20% non-iron). It is a slow, continuous increase starting at the 1st Trimester & MAY accelerate in the 3rd.
Erythrocyte mass increases as well
The increase is stimulated by;
- Increased Erythropoietin
- hPL, PRL, & Prog.
Describe the change in Erythrocytes in PP
50% of Erythrocytes are lost at birth.
Erythrocyte production temporarily ceases & remaining increased erythrocytes are lost through normal Catabolism.
Describe the changes in hematocrit during pregnancy
Hematocrit levels decrease 3-5% to 33.8% @ term. The decrease is due to hemodilution & is inversely proportional to Plasma Volume (lowest level in 2nd Tri.)
Describe the changes in Hematocrit levels in PP
Hematocrit levels return to normal by 4-6weeks as a result of RBC catabolism.
Describe the changes in Hemoglobin during pregnancy.
Hemoglobin decreases 2-10% to 12.1-12.5 g/dl at term. The change is slow and little change is observed to 16 weeks IF adequate Iron & Folate are present. The lowest point is at 16-22 weeks, followed by a slight increase to term.
Due to Hemodilution (Increase of 65-150g in total body Hb).
Describe Hemoglobin levels during IP & PP.
IP: Hb levels increase due to stress & Dehydration
PP: Initial Decrease, but soon stabilize @ 2-4days. Normal levels restored by 4-6 weeks
Describe the change in Leukocytes during pregnancy
Leukocytes increase by 8% to 5000-12000/mm3 starting in 2nd month and primarily consists of Neutrophils.
Due to: Increased Estrogen & Cortisol
Describe the change in Leukocytes during IP & PP
IP: Leukocytes increase to 25,000-30,000/mm3
PP: Leukocytes Decrease to 6000-10,000/mm3; Normal levels by 4-7 days.
Describe how platelet levels change during pregnancy
Platelets can potentially decrease, however they remain in normal adult ranges (150-400k/mm3). Platelet consumption, however does increase during pregnancy.
Due to: Hemodilution
Describe how Platelet levels change during IP & PP
IP: Platelets decrease by 20% w/ placental separation
PP: Platelets increase by 3-5 days with a gradual return to normal levels
Describe how Total Plasma Protein levels change during pregnancy.
What is the Significance?
Total Plasma Protein levels decrease (10-14%)
Due to: Estrogen & Prog.
Significance:
- Decreased Colloid Osmotic Pressure (Edema formation)
- Altered protein binding of calcium, drugs, etc.
Describe how Fibrinogen levels change during pregnancy.
What is the significance?
Fibrinogen levels increase (50-80%)
Due to: Hemodilution
Significance:
- Alterations in Hemostasis
- Decreased Erythrocyte Sedimentation Rate
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Reproductive Endocrinology31
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Reproductive Aging38
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Placental Physiology20
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Parturition & Uterine Physiology20
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Post-Partum Physiology1
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Normal Menstrual Cycle (Baseline)1
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E2: Fetal Assessment44
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E2: Perinatal Pharm32
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E2: Hematologic Systems26
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E2: CV-Maternal Adaptations10
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E2 Respiratory: Maternal Adaptations1
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E2: Respiratory: Neonatal Physiology15
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E2: Renal: Maternal Adaptations12
