Systemic Changes During Pregnancy
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SYSTEMIC CHANGES DURING PREGNANCY
CHANGES OF THE SKIN DURING PREGNANCY a. Linea Nigra. This is a dark line that runs from the umbilicus to the symphysis pubis and may extend as high as the sternum. b. Mask of Pregnancy (Chloasma). This is the brownish hyper pigmentation of the skin over the face and forehead. c. Striae Gravidarum (Stretch Marks). It reflects a separation within underlying connective tissue of the skin. This occurs over areas of maximal stretch--the abdomen, thighs, and breasts. d. Sweat Glands. Activity of the sweat glands throughout the body usually increases which causes the woman to perspire more profusely during pregnancy. e. Vascular nevi- small, fiery-red branching spots are sometimes seen in the neck, chest, face, arms and legs. This is due to increased estrogen levels. CHANGES OF THE CIRCULATORY SYSTEM DURING PREGNANCY a. Blood Volume • Blood volume increases gradually by 30 to 50 percent (1500 ml to 3 units). This is to compensate for the blood loss at birth. • Physiologic anemia occurs as the plasma increase exceeds the increase in red blood cell production. b. Cardiac Output • Cardiac output increases about 25 to 50 percent during the first and second trimester to accommodate for hypervolemia. (This is not a problem for patients with a normal heart. A patient with a diseased heart is especially at risk for cardiac decompensation 28 to 35 weeks of pregnancy when the blood volume and cardiac load are at their peak; also, during labor and immediately after delivery when rapid hemodynamic changes occur.) • Change in output is reflected in the heart rate. It usually increases by 10 beats per minute. • Heart size increases and is elevated upward and to the left side because of the displacement of the diaphragm as the uterus enlarges. c. Blood Pressure • Normally, the patient's blood pressure will not rise. It will decrease on the second trimester due to the expansion of the placenta but it will rise again on the third trimester to first trimester level. d. Venous Return. • The lower extremities are often hampered in the last months of pregnancy due to the expanding uterus restricting physical movement and interfering with the return of blood flow. This results in swelling of the feet and legs. This can also lead to varicosities of the vulva, rectum and legs. CHANGES OF THE RESPIRATORY SYSTEM DURING PREGNANCY • The respiratory rate rises to 18 to 20 to compensate for increased maternal oxygen consumption, which is needed for demands of the uterus, the placenta, and the fetus. • Approximately 60% to 70% of pregnant women experience shortness of breath; this is because the diaphragm may be displaced by as much as 4cm as the uterus enlarges. • Nasal stuffiness and epistaxis (nosebleeds) are also common during pregnancy, secondary to vascular congestion caused from the increased estrogen levels. CHANGES OF BODY TEMPERATURE DURING PREGNANCY • A slight increase in body temperature in early pregnancy is noted because of the secretion of progesterone from the corpus luteum. The temperature returns to normal at about the 16th week of gestation as the placenta takes over the function of the corpus luteum.
CHANGES OF THE URINARY SYSTEM DURING PREGNANCY • The kidneys must work extra hard excreting the mother's own waste products plus those of the fetus. There is an increase in urinary output and a decrease in the specific gravity. To provide sufficient fluid volume for effective placental exchange, the total body water increases to 7.5L. • The patient may develop urine stasis and pyelonephritis in the right kidney. This is due to pressure on the right ureter resulting from displacement of the uterus slightly to the right by the sigmoid colon. • Frequent urination is a complaint during the first through third trimester. CHANGES OF THE SKELETAL SYSTEM DURING PREGNANCY • There is a realignment of the spinal curvatures during pregnancy to maintain balance. It is due to the increase in size of the uterus and pressure on the abdominal wall. The patient walks with head and shoulders thrust backward and chest protruding outward to compensate (lordosis). This gives the patient a "waddling" gait. • There is a slight relaxation and increased mobility of the pelvic joints, which allows stretching at the time of delivery of the infant, this is due to the production of relaxin hormones by the placenta. CHANGES OF THE GASTROINTESTINAL SYSTEM DURING PREGNANCY • Nausea and vomiting may occur as a result of the secretion of Hcg • As the uterus enlarges. It rises up and out of the pelvic cavity. This action displaces the stomach, intestines, and other adjacent organs. • Peristalsis is slowed because of the production of the hormone progesterone, which decreases tone and mobility of smooth muscles. This slowing enhances the absorption of nutrients and slows the rate of secretion of hydrochloric acid and pepsin. Slow emptying may increase nausea and heartburn (pyrosis). Relaxation of the cardiac sphincter may increase regurgitation and chance for heartburn. Movement through the large intestines is also slowed due to an increase in water consumption from this area. This increases the chance for constipation. • Hemorrhoids may occur as a result of increased venous pressure. CHANGES OF SELECTED GLANDS OF THE ENDOCRINE SYSTEM DURING PREGNANCY • Parathyroid Gland. This gland increases in size slightly. It meets the increased requirements for calcium needed for fetal growth. • Pituitary Gland. Near the end of term, the posterior pituitary will begin to secrete oxytocin that was produced in the hypothalamus and stored there. It will serve to initiate labor. Prolactin is also produced for lactation. There is also an increase in production of growth hormone and melanocyte-stimulating hormone • Placenta. Produces estrogen, progesterone, hCG, human placental lactogen, relaxin and prostaglandins. Estrogen causes breast and uterine enlargement and palmar erythema. Progesterone inhibits uterine contractility, relaxin, softens the cervix and the collagen in joints. hCG stimulates progesterone and estrogen synthesis in early pregnancy. hPL serves as an antagonist to insulin. CHANGES OF THE IMMUNE SYSTEM DURING PREGNANCY • Immunologic compentency decreases to prevent the woman’s body from rejecting the fetus. Immunologic G (IgG) is also decreased, which can make a woman more prone to infection during the pregnancy
CHANGES OF THE SKIN DURING PREGNANCY a. Linea Nigra. This is a dark line that runs from the umbilicus to the symphysis pubis and may extend as high as the sternum. b. Mask of Pregnancy (Chloasma). This is the brownish hyper pigmentation of the skin over the face and forehead. c. Striae Gravidarum (Stretch Marks). It reflects a separation within underlying connective tissue of the skin. This occurs over areas of maximal stretch--the abdomen, thighs, and breasts. d. Sweat Glands. Activity of the sweat glands throughout the body usually increases which causes the woman to perspire more profusely during pregnancy. e. Vascular nevi- small, fiery-red branching spots are sometimes seen in the neck, chest, face, arms and legs. This is due to increased estrogen levels. CHANGES OF THE CIRCULATORY SYSTEM DURING PREGNANCY a. Blood Volume • Blood volume increases gradually by 30 to 50 percent (1500 ml to 3 units). This is to compensate for the blood loss at birth. • Physiologic anemia occurs as the plasma increase exceeds the increase in red blood cell production. b. Cardiac Output • Cardiac output increases about 25 to 50 percent during the first and second trimester to accommodate for hypervolemia. (This is not a problem for patients with a normal heart. A patient with a diseased heart is especially at risk for cardiac decompensation 28 to 35 weeks of pregnancy when the blood volume and cardiac load are at their peak; also, during labor and immediately after delivery when rapid hemodynamic changes occur.) • Change in output is reflected in the heart rate. It usually increases by 10 beats per minute. • Heart size increases and is elevated upward and to the left side because of the displacement of the diaphragm as the uterus enlarges. c. Blood Pressure • Normally, the patient's blood pressure will not rise. It will decrease on the second trimester due to the expansion of the placenta but it will rise again on the third trimester to first trimester level. d. Venous Return. • The lower extremities are often hampered in the last months of pregnancy due to the expanding uterus restricting physical movement and interfering with the return of blood flow. This results in swelling of the feet and legs. This can also lead to varicosities of the vulva, rectum and legs. CHANGES OF THE RESPIRATORY SYSTEM DURING PREGNANCY • The respiratory rate rises to 18 to 20 to compensate for increased maternal oxygen consumption, which is needed for demands of the uterus, the placenta, and the fetus. • Approximately 60% to 70% of pregnant women experience shortness of breath; this is because the diaphragm may be displaced by as much as 4cm as the uterus enlarges. • Nasal stuffiness and epistaxis (nosebleeds) are also common during pregnancy, secondary to vascular congestion caused from the increased estrogen levels. CHANGES OF BODY TEMPERATURE DURING PREGNANCY • A slight increase in body temperature in early pregnancy is noted because of the secretion of progesterone from the corpus luteum. The temperature returns to normal at about the 16th week of gestation as the placenta takes over the function of the corpus luteum.
CHANGES OF THE URINARY SYSTEM DURING PREGNANCY • The kidneys must work extra hard excreting the mother's own waste products plus those of the fetus. There is an increase in urinary output and a decrease in the specific gravity. To provide sufficient fluid volume for effective placental exchange, the total body water increases to 7.5L. • The patient may develop urine stasis and pyelonephritis in the right kidney. This is due to pressure on the right ureter resulting from displacement of the uterus slightly to the right by the sigmoid colon. • Frequent urination is a complaint during the first through third trimester. CHANGES OF THE SKELETAL SYSTEM DURING PREGNANCY • There is a realignment of the spinal curvatures during pregnancy to maintain balance. It is due to the increase in size of the uterus and pressure on the abdominal wall. The patient walks with head and shoulders thrust backward and chest protruding outward to compensate (lordosis). This gives the patient a "waddling" gait. • There is a slight relaxation and increased mobility of the pelvic joints, which allows stretching at the time of delivery of the infant, this is due to the production of relaxin hormones by the placenta. CHANGES OF THE GASTROINTESTINAL SYSTEM DURING PREGNANCY • Nausea and vomiting may occur as a result of the secretion of Hcg • As the uterus enlarges. It rises up and out of the pelvic cavity. This action displaces the stomach, intestines, and other adjacent organs. • Peristalsis is slowed because of the production of the hormone progesterone, which decreases tone and mobility of smooth muscles. This slowing enhances the absorption of nutrients and slows the rate of secretion of hydrochloric acid and pepsin. Slow emptying may increase nausea and heartburn (pyrosis). Relaxation of the cardiac sphincter may increase regurgitation and chance for heartburn. Movement through the large intestines is also slowed due to an increase in water consumption from this area. This increases the chance for constipation. • Hemorrhoids may occur as a result of increased venous pressure. CHANGES OF SELECTED GLANDS OF THE ENDOCRINE SYSTEM DURING PREGNANCY • Parathyroid Gland. This gland increases in size slightly. It meets the increased requirements for calcium needed for fetal growth. • Pituitary Gland. Near the end of term, the posterior pituitary will begin to secrete oxytocin that was produced in the hypothalamus and stored there. It will serve to initiate labor. Prolactin is also produced for lactation. There is also an increase in production of growth hormone and melanocyte-stimulating hormone • Placenta. Produces estrogen, progesterone, hCG, human placental lactogen, relaxin and prostaglandins. Estrogen causes breast and uterine enlargement and palmar erythema. Progesterone inhibits uterine contractility, relaxin, softens the cervix and the collagen in joints. hCG stimulates progesterone and estrogen synthesis in early pregnancy. hPL serves as an antagonist to insulin. CHANGES OF THE IMMUNE SYSTEM DURING PREGNANCY • Immunologic compentency decreases to prevent the woman’s body from rejecting the fetus. Immunologic G (IgG) is also decreased, which can make a woman more prone to infection during the pregnancy
