Boston: Early Signs of Pregnancy: Adaptive Changes of Other Systems

Boston,

A women experience various physiological effects based on a combination of hormonal and mechanical changes during pregnancy. Hormonal influences tend to increase as the pregnancy progress. The mechanical changes reach a peak in the seventh or eighth month and then gradually decline as the pregnancy nears completion.

A women may assume that she is pregnant because she has skipped her menstrual period or experiences nausea and vomiting, changes in breast sensations and size, or increased urinary frequency (presumptive signs of pregnancy). If she suspects she is pregnant, the woman should seek a pregnancy test. The woman should be cautioned against relying on these tests, because concurrent medication or substance use may cause a false result. If performed too early, a home pregnancy test may also produce a false negative result due to a low level of human chorionic gonadotropin. This hormone, produced by the placenta, is found in a pregnant woman´s urine and blood. As the pregnancy progresses, the woman may have both probable and positive signs of pregnancy, objective changes that increasingly verify that a pregnancy exists. With the advent of first trimester, sophisticated testing with ultrasonography, health care providers now determine fetal presence and placental adequacy early in pregnancy. This technology, using high frequency sound waves that bounce off the fetus and are interpreted by a computer, allows visualization of the fetus and gestational structures throughout pregnancy.

In addition to pregnancy related changes in the reproductive system, adaptive changes in other body systems occur. The urinary system undergoes dramatic changes during gestation; a 50% increase in glomerular filtration rate occurs related to the influences of estrogen and progesterone. These hormones also cause smooth muscle relaxation in the gastrointestinal tract, resulting in maternal constipation, heartburn, and increased salivation.

Circulatory system changes also begin early in pregnancy, with an increase in cardiac output of 30% to 40% by the end of the first trimester. Total blood volume increases 30% to 45% during pregnancy. Physiological anemia of pregnancy may result because of an increase in the proportion of plasma to red blood cells.

Respiratory system changes include increased tidal volume during pregnancy, although toward the end of pregnancy he enlarging uterus causes some shortness of breath for many women. This continues until the baby descends into the pelvis during the final weeks of pregnancy.

Increased elasticity and softening of connective tissue of the musculo-skeletal system cause relaxation of the joints, especially the pelvic joints that support the pregnancy but must stretch during labor and delivery. Lumbar and dorsal curves of the spine increase late in pregnancy and contribute to low back pain and the waddle of pregnancy.

Changes in the integumentary system occur. Hormones cause many pregnant women to gain stretch marks on their abdomen and breasts, a darkened line from the symphysis pubis to the umbelicus and darkening of the skin across the forehead and nose. The metabolic and endocrine changes that occur with pregnancy to support optimal fetal growth and development are dramatic.

Source by Eric Spinosus

Early Signs of Pregnancy: Adaptive Changes of Other Systems