Serious complications could arise from cardiovascular diseases during pregnancy. Five percent of maternal deaths are due to cardiovascular diseases, however, improved management for women with these diseases are available today, making them safe from delivering their babies despite their conditions.
Learn the common cardiovascular and hematologic diseases in pregnancy and what you can do as a nurse.
Cardiovascular Diseases in Pregnancy
Cardiac disease: Left-sided Heart Failure
- Left-sided heart failure happens when the left ventricle cannot shunt the blood forward that it received by the left atrium from the pulmonary circulation.
- Failure mostly occurs at the level of the mitral valve.
- When the mitral valve could not push the blood forward, it causes back pressure on the pulmonary circulation which results in pulmonary hypertension.
- Pulmonary hypertension in pregnant women could precipitate a high-risk pregnancy for spontaneous miscarriage, preterm labor, or maternal death.
- The placenta may not receive adequate blood because of the decreased peripheral circulation.
- The woman would have difficulty in sleeping due to the worsening pulmonary edema.
- Advise the woman with left-sided heart failure to sleep with her chest and head elevated.
- Heart action is more effective at rest, so the interstitial fluid returns to the circulation and overburdens it, causing increased left-sided failure and pulmonary edema.
- When complications of left-sided failure occur, these may result in impaired blood flow to the uterus, poor placental perfusion, intrauterine growth restriction, and fetal mortality.
- The woman needs to have a serial ultrasound and nonstress tests on the 30th to 32nd week of her pregnancy to monitor fetal health.
Cardiac Disease: Right-sided Heart Failure
- Right-sided heart failure happens when the output of the right ventricle is less than the blood volume received by the right atrium from the vena cava.
- Back-pressure from this results in congestion of the systemic venous circulation and also decrease in cardiac output.
- Pressure is high in the vena cava, leading to jugular vein distention and increased portal circulation.
- Liver is enlarged, and this could cause extreme dyspnea and pain in a pregnant woman because the enlarged liver is pressed upward by the enlarged uterus, and extreme pressure is placed on the diaphragm.
- Eisenmenger syndrome is the congenital anomaly that would most likely cause right-sided heart failure in women of reproductive age.
- It is a right to left atrial or ventricular septal defect with pulmonary stenosis.
- Women with this anomaly are advised to avoid getting pregnant.
- Oxygen administration and frequent assessment of the arterial blood gas is needed to ensure fetal growth once the woman gets pregnant.
- The nurse’s role during labor is to closely monitor for hypotension after epidural anesthesia.
Chronic Hypertensive Vascular Disease
- Women already diagnosed with chronic hypertensive vascular disease already has an elevated blood pressure (140/90 mmHg and above) in pregnancy.
- Both the mother and the fetus are compromised because of the poor placental perfusion which places the fetal well-being in jeopardy.
- The primary care provider could prescribe beta-blockers and ACE inhibitors to decrease the blood pressure by peripheral dilation, but not to reduce it below the threshold that allows for good placental circulation.
Venous Thromboembolic Disease
- Venous thromboembolic disease happens more likely in pregnant women because of the stasis of blood in the lower extremities due to uterine pressure and the effect of elevated estrogen on the hypercoagulability of the woman.
- The triad of stasis, vessel damage, and hypercoagulation results in thrombus formation in the lower extremities.
- Women who are 30 years and older have an increased risk of developing deep vein thrombosis leading to pulmonary emboli.
- Pain and redness in the calf of the leg usually signal thrombus formation.
- Thrombus formation can be prevented by avoiding the use of constrictive knee-high stockings.
- Advise the woman not to sit with her legs crossed at the knee and to avoid standing in one position for a long time.
- A thrombus that occurred during pregnancy is diagnosed by Doppler ultrasonography and a woman’s history.
- The woman will be placed on bed rest and intravenous heparin administration for 24 to 48 hours.
- Women who are taking heparin during pregnancy are not candidates for routine episiotomy or epidural anesthesia to prevent hemorrhage.
- PTT determination should be continued during labor.
- A breastfeeding woman cannot take heparin or Coumadin, or Coumadin should be used cautiously.
- The main danger of thrombophlebitis is pulmonary embolism or a clot that lodges in the pulmonary artery, blocking the circulation to the lungs and heart.
- Symptoms of pulmonary embolism include chest pain, sudden onset of dyspnea, cough with hemoptysis, tachycardia, and severe dizziness or fainting.
- Pulmonary embolism is recognized as an immediate emergency.
Hematologic Disorders in Pregnancy
Coagulation disorders or blood formation makeup hematologic disorders among pregnant women. Since childbirth involves the loss of a lot of blood, hemorrhage would be very dangerous to a woman with these disorders.
- Iron-deficiency anemia is the most common anemia among pregnant women, mainly because many women enter pregnancy already deficient in iron stores because of low intake of iron.
- A hemoglobin level below 12mg/dl with hematocrit below 33% is a possible sign of iron deficiency.
- Iron-deficiency anemia is a microcytic, hypochromic anemia because when inadequate iron is ingested, it would be unavailable for incorporation into red blood cells.
- Iron-deficiency anemia is mildly associated with low birth weight and preterm birth.
- Extreme fatigue and poor exercise tolerance because she cannot transport oxygen effectively.
- Advise the woman to take prenatal vitamins containing an iron supplement of 60 mg elemental iron.
- Instruct her to eat a diet high in iron such as green leafy vegetables, meat, legumes, and fruit.
- When a pregnant woman has developed anemia during pregnancy, she will be prescribed with 120 to 200 mg elemental iron per day in the form of ferrous sulfate or ferrous gluconate.
- Iron is best absorbed in an acidic medium, so advise the woman to take her iron supplements with orange juice or a vitamin c supplement.
- Side effects of iron therapy include constipation and gastric irritation.
- Ferrous sulfate turns stool black so caution women with this side effect.
Folic Acid-Deficiency Anemia
- Folic acid is vital for the normal formation of red blood cells in the mother.
- It also prevents neural tube defects in the fetus.
- Folic acid anemia is a megaloblastic anemia wherein the mean corpuscular volume is elevated.
- This anemia is most apparent during the second trimester of pregnancy and may contribute to early miscarriage or premature separation of the placenta.
- Women who are expecting to be pregnant are advised to take 400 µg of folic acid daily.
- Advise the woman to take folacin rich foods such as green leafy vegetables, oranges, and dried beans.
Sickle Cell Anemia
- Sickle cell anemia is a recessively inherited hemolytic anemia caused by an abnormal amino acid in the beta chain of hemoglobin.
- Majority of the red blood cells are irregular or sickle-shaped, so they cannot carry the same amount of hemoglobin as the normal red blood cells do.
- At high altitudes, the blood becomes more viscous than usual because the cells tend to clump together because of their irregular shape.
- Reduced blood flow to the organs is the result of the vessel blockage of the clumping red blood cells.
- These cells will hemolyze and reduce in number, causing severe anemia.
- A pregnant woman with sickle cell anemia is more prone to bacteriuria, so a clean catch urine sample is collected during pregnancy to detect the disease while it is asymptomatic.
- The woman’s diet must contain sufficient amounts of folic acid to help in building new red blood cells.
- Fluid intake should also be emphasized because dehydration can lead to a sickle cell crisis.
- Advise the woman to elevate her legs while sitting or lie on her left side while sleeping to encourage venous return from the lower extremities.
- Instruct the woman to avoid standing for long periods during the day.
- Fetal health is monitored through ultrasound at 16 to 24 weeks to assess for intrauterine growth restriction.
- An exchange transfusion is needed to replace sickled cells with non-sickled cells.
- Iron supplements are not given to pregnant women who already have sickle cell crisis because they cannot still incorporate iron and may cause excessive build up.
- When a sickle cell crisis occurs, controlling pain, oxygen administration, and increasing the fluid volume of the circulatory system to lower viscosity are essential interventions.
- To detect if the fetus has acquired the disease, electrophoresis of red blood cells by percutaneous umbilical blood sampling or amniocentesis will be performed to reveal the presence of the disease on the beta chains present in utero.
Practice Quiz: Cardiovascular Diseases in Pregnancy
Test your knowledge about cardiovascular diseases in pregnancy with these questions.
1. Where would you classify neglected prenatal care as the factors for a high-risk pregnancy?
2. What part of the heart fails mainly in a left-sided heart failure?
A. Aortic valve
B. Right atrium
C. Mitral valve
D. Right ventricle
3. What happens in right-sided heart failure?
A. Output of the right ventricle is less than the volume received by the right atrium from the vena cava.
B. Output of the right atrium is less than the volume received by the right ventricle from the pulmonary circulation.
C. Output of the left ventricle is less than the volume received by the left atrium from the vena cava.
D. Output of the left atrium is less than the volume received by the left ventricle from the vena cava.
4. Why are ACE inhibitors and beta-blockers administered to a pregnant woman with chronic hypertensive vascular disease?
A. To increase the woman’s blood pressure.
B. To prevent clot formation.
C. To dilate the peripheral veins and decrease blood pressure.
D. To reduce the blood pressure past the threshold for good placental perfusion.
5. What is the triad for thromboembolism?
A. Vessel damage, stasis, hypotension
B. Stasis, hypertension, heart attack
C. Hypercoagulation, stasis, hyperthermia
D. Stasis, vessel damage, hypercoagulation
Answers and Rationale
1. Answer: B. Social
- B: Lack of or neglected prenatal care is a social factor that contributes to the development of a high-risk pregnancy.
- A: Physical factors may include obesity, hemorrhage, infection, etc.
- C: There is no category for spiritual factors. D: Psychological factors may include loss of support person, poor acceptance of pregnancy, history of mental illness, etc.
- D: Psychological factors may include loss of support person, poor acceptance of pregnancy, history of mental illness, etc.
2. Answer: C. Mitral valve
- C: The mitral valve could not push the blood forward which causes back-pressure to the pulmonary circulation.
- A: The aortic valve is functioning normally in left-sided heart failure.
- B: It is the left atrium that cannot receive blood from the left ventricle because of its inability to shunt the blood forward.
- D: The left ventricle, not the right ventricle, cannot shunt the blood forward towards the left atrium to the pulmonary circulation.
3. Answer: A. Output of the right ventricle is less than the volume received by the right atrium from the vena cava.
- A: This is the correct sequence in the pathophysiology of right-sided heart failure.
- B: The right ventricle has the decreased output that is shunted forward to the right atrium from the vena cava.
- C: It is not the left but the right ventricle that shunts forward its output to the right atrium and not the left atrium.
- D: It is the right rather than the left ventricle, and instead of the left ventricle, it should be the right ventricle.
4. Answer: C. To dilate the peripheral veins and decrease blood pressure.
- C: Both drugs help to reduce blood pressure by peripheral dilation.
- A: The woman’s blood pressure needs to be reduced.
- B: Anticoagulants are responsible for preventing clot formation.
- D: The blood pressure must not be reduced past the threshold for good placental perfusion.
5. Answer: D. Stasis, vessel damage, hypercoagulation
- D: Stasis, vessel damage and hypercoagulation results in thrombus formation.
- A: Hypertension, not hypotension, may happen with thrombus formation but it is not part of the triad.
- B: Heart attack is not part of the triad, however, it can become the end result of thrombus formation.
- C: Hyperthermia does not occur in thrombus formation.