Physiological Effects of a Pregnancy on a Woman

Physiological effects of a pregnancy on a woman • • • • • Respiratory system changes: - Rises to compensate for increased maternal oxygen consumption, which is needed for the uterus, placenta and foetus. ✓ Increased minute ventilation. ✓ Decreased functional capacity. ✓ Increased tidal volume. ✓ Dyspnoea ✓ Respiratory alkalosis. Cardiovascular system changes: - Blood vessels grow. - Increased cardiac output. - Elevated resting heart rate. - Decreased peripheral resistance. - BP decreases in the 2nd trimester. GIT - As the uterus enlarges it rises up and out of the pelvic cavity. - This causes displacement of the stomach, intestines, and other adjacent organs. - Progesterone causes relaxation of the lower oesophageal sphincter which will cause creased gastric motility, constipation, increased acid reflux and heart burn. Breasts - Due to the increased estrogen there, breasts will become large and tender, and the nipples stick out. - This is a prep for breast feeding. - By the end of the third trimester -> colostrum (pre-milk which is yellow and watery leaks out. Endocrine The placenta acts as a temporary endocrine gland during pregnancy. It produces large amounts of oestrogen and progesterone by the 10th to 12th week of pregnancy. It serves to maintain the growth of the uterus, helps to control uterine activity, and is responsible for many of the maternal changes in the body. - Pregnant women may feel warmer or experience “hot flashes” caused by increased hormonal level and basal metabolic rate. - The parathyroid gland increases in size slightly to meet the increased requirements for calcium. - Near the end of the term, the posterior pituitary will begin to secrete oxytocin that wills serve to initiate labour. - At birth, the anterior pituitary will begin to secrete prolactin. This stimulates the production of breast milk. Abdomen - In the second trimester the abdomen begins to expand and by the end of it the top of the uterus will reach near the rib cage. Urinary system changes - • • uterus puts pressure on the bladder, urethra and pelvic floor muscles, which leads to temporary bladder control problems like frequent urination and even leaking of urine when sneezing, cough or laughing. - The kidneys may work extra hard excreting the mother’s and fetus waste products. These kidneys must work extra hard to excrete the waste products of both the mother and fetus. MSK changes - There is a realignment of the spinal curvatures to maintain balance; this produces a shift in the posture with exaggerated lumbar lordosis, leading to the typical gait of late pregnancy. - Increased ligamental laxity, caused by increased levels of relaxin, contribute to back pain and pubic symphysis dysfunction. The ligaments that hold the pelvic bones together gradually loosen to prepare the mother for labor and birth - Leg cramps can be caused by fatigue from carrying pregnancy weight, compression of blood vessels in the legs, excess phosphorous, a shortage of calcium or magnesium, and fluctuation of pregnancy hormones. - Feet and ankles may swell because of the extra fluid in the body during pregnancy. Skin changes - Stretch marks (striae gravidarum) usually appear in the second half of pregnancy on the thighs, buttocks, abdomen, and breasts. These scars are caused by the stretching of the skin. - Hyperpigmentation of the umbilicus, nipples, abdominal midline, and face (chloasma) are common due to the hormonal changes of pregnancy. - Hyperdynamic circulation and high levels of oestrogen may cause spider veins (spider naevi) and reddening of the palms (palmar erythema). - • •