Nm 602 Module 4 Study Guide/unit A

Front 1

List the prenatal changes in blood and plasma volume

Back 1

Hypervolemia of pregnancy. Circulating blood volume increases by 30-40% (approx. 1.5 liters) Increased plasma volume, increased RBC volume. Blood volume changes begin at 6-8 weeks, and peak at 28-34 weeks, about 1200-1600 ml higher than a nonpregnant woman. The increased volume leads to hemodilution with a net decrease in RBC volume and total circulating plasma proteins.

Front 2

How are the blood and plasma volumes different in the multipara?

Back 2

A greater than normal increase in plasma volume has been observed in multiparous women.

Front 3

How are the blood and plasma volumes different in maternal obesity?

Back 3

A greater than normal increase in plasma volume has been observedInfants

Front 4

How are the blood and plasma volumes different in infants that are large for gestational age?

Back 4

A greater than normal increase in plasma volume has been observed

Front 5

How are the blood and plasma volumes different in prolonged pregnancy?

Back 5

A greater than normal increase in plasma volume has been observed

Front 6

How are the blood and plasma volumes different in multiple gestation?

Back 6

Plasma volume increases up to 70% over nonpregnant women in twin gestation, and even further elevations have been noted in triplet and other multiple gestations. PG 227

Front 7

What is the etiology of plasma volume increase in pregnancy?

Back 7

Poorly understood, but is thought to be related to the effects of nitric oxide-mediated vasodilation on the renin-angiotensin-aldosterone system and subsequent sodium and water retention. Changes are also influenced by hormonal influences, especially the effects of progesterone, on the vasculature of the venous system lead to decreased venous tone, increased capacity of the veins and venules, and decreased vascular resistance. PG228

Front 8

List the changes in blood cells, plasma, coagulation factors in pregnancy.

Back 8

RBC volume increases, with average increase of up to 33% (450 ml).
Increased circulating erythropoietin, stimulates erythopoiesis and accelerated RBC production.
The increased RBC production results in a moderate erythroid hyperplasia of the bone marrow and an increase in reticulocyte count. The mean cell diameter and thickness of the RBC’s changes, resulting in a more spherical shape cell.
Hemoglobin and hematocrit decrease. PG229
Total WBC volume increases. WBC range from 5000-12000, with values as high as 15000. The increased WBC count is due to neutrophilia with an elevation in mature leukocyte forms. PG230
Platelets values do not change significantly. A slight decrease in platelet count and increase in platelet aggregation during the last 8 weeks of pregnancy has been reported. Acceptable range for platelets is 150,000-400,000. PG 230
Plasma proteins decrease 10-14%.
Plasma albumin decreases (there is an absolute increase in albumin concentration during the first trimester, there is a relative decrease due to increased blood volume and hemodilution). Decreased albumin leads to a net decrease in colloid osmotic (oncotic) pressure, reducing the normal forces counteracting edema formation. PG 230
Globulin concentration-demonstrates both absolute and relative increases, leading to progressive falls in the albumin-to-globulin ratio. PG 230
Fibrinogen demonstrates both absolute and relative increases of 50-80%.
The erythocyte sedimentation rate increases. PG231
Decrease in serum electrolytes reduce plasma osmolarity by 8-10 mOsm/L
Serum iron decreases, serum ferritin falls, but with adequate iron serum ferritin levels stabilize by 28 weeks. PG 231
Levels of serum lipids rise, with marked elevations in cholesterol and phospholipids.
Serum alkaline phosphatase increases pg231

Front 9

List the hematologic parameter changes seen during labor and delivery. How does hemostasis change during the intrapartum period?

Back 9

Hemoglobin levels increase slightly in labor. WBC count increases during labor and immediate postpartum period, with values up to 25,000-30,000. ESR rises too. PG 235
The coagulation system undergoes further activation during the intrapartum period. Concentrations of clotting factors increase during labor. PT shortens significantly (especially during third stage with clotting at the placental site.) Levels of fibrinogen and plasminogen may also decrease as a result of their increased utilization after placental separation. Factor VII complex increases in L&D. Factor V increases after placental separation, which contributes to activation of clotting via the extrinsic system. PG 235
Fibrinolytic activity decreases in L&D, enhancing formation of clots at placental site after separation. This promotes development of of a hemostatic endometrial fibrin mesh over wound. About 5-10% of total body fibrin is deposited at this site. 235.
Fibrin levels and fibrin-fibrinogen degradation products (FDP) reach their nadir with placental separation. FDP and d-dimer both increase after delivery. 235
Platelets fall about 20% with placental separation (due to clotting at separation site)
Platelet activation and fibrin formation are maximal at delivery. (this protects from hemorrhage and excessive blood loss at delivery by providing rapid hemostasis following removal of placenta). 235
Pregnancy has been called an acquired hypercoagulable state. Increased risk for thrombosis and consumptive coagulopathies such as DIC (disseminated intravascular coagulation). 231

Front 10

Describe the changes in the hematologic and hemostatic systems in the postpartum period.

Back 10

Increased RBC production ceases early postpartum.
Mean hemoglobin (hgb) levels decrease slightly in first 24 hours, then plateau for 4 days, followed by a slow rise to day 14. A 500 ml blood loss (normal for vag. del.) usually results in a 1 g reduction in hbg
Hematocrit follows same pattern and returns to nonpregnant levels in 4-6 weeks.
Reticulocyte count increases for 1-2 days, then rapid decline.
Little change in serum ferritin levels in first 2 weeks, then increase occurs by 5-8 weeks (more marked after vag. del)
decrease in transferrin
Increase in serum iron.
Marked decrease in C-reactive protein
WBC return to norm values by 6 days postpartum (pp)
Eosinophils (which disappear from blood during delivery) return by 3 days pp
Basophil and monocytes remain unchanged
Platelet count falls at placental separation, begins increasing at 3-4 days pp
Fibrin degradation products increase after placental separation
Fibrinolytic activity returns to norm as early as 1 hr after delivery and fibrinolysis to normal 24-48 hr pp.
PAI-1 and PAI-2 decrease after separation of placenta, PAI-1 returns to norm levels by 5 weeks, PAI-2 (that was originally produced by placenta) can be detected for up to 8 weeks
Secondary increases in fibrinogen, factor V, and factor VIII occur in first week, return to predelivery by 1-7 days, then slowly return to nonpregnant levels.
Clotting factors slowly decrease, reaching lowest level by 7-10 days
Factor V11 and X return to normal by 2 weeks,’
Hemostatic system returns to nonpregnant status at 4-6 weeks pp, but levels of free protein S may remain low for up to 8 weeks.
Activated protein C resistance decreases to nonpregnant values by 1-7 days
Changes in flow velocity and diameter of deep veins may take 6 weeks to return to norm
Postpartum=increased risk for thromoembolism
PG 237

Front 11

Why is a pregnant woman at risk for anemia, thromboembolic events and coagulopathies?

Back 11

Changes in the hematologic system and in hemostasis increase a women’s need for iron and other nutrients and place her at risk for anemai, thromboembolic events, and coagulopathies PG 237-238

Front 12

What are the advantages of hypervolemia in pregnancy?

Back 12

Allows the woman to tolerate the many changes of pregnancy and delivery, and helps to 1) Meet the demands of the enlarged uterus and hypertrophied vascular system while maintaining normal systemic blood pressure, 2)Allows the woman to toerlate blood loss at delivery, 3)protect the woman from impaired venous return and hypotension with position changes late in the third trimester (reduce risk of supine hypotension), 4) enhance maternal-fetal exchange of gases and nutrients, and 5) increase cutaneous blood flow fourfold to sevenfold, thus assisting with heat dissipation via the skin. PG238

Front 13

What is the most common cause of anemia in pregnancy?

Back 13

Iron deficiency. pg 239

Front 14

If the mother is iron deficient, will the fetus suffer?
Why?

Back 14

NO
The placenta will continue to transport iron to the fetus, regardless of the Mother’s iron stores or anemia, therefore the fetus will have it’s requirements met. PG 238

Front 15

When during pregnancy does intestinal iron absorption increase?

Back 15

Second half of pregnancy PG 238

Front 16

If a woman’s serum ferritin levels are low at 20 weeks gestation, is iron supplementation needed?

Back 16

Controversial. But, yes. PG 238

Front 17

What are 3 factors that predispose pregnant women to thromboembolitic events?

Back 17

Virchow Triad---Stasis, Altered coagulation, and vascular damage. pg241