Physical And Physiologic Changes In Pregnancy Flashcards
Define antepartum
Begins with the first day of the last menstrual period (LMP)
Ends with true labor
Divided into three trimesters, each approximately three months in length
How is the uterus before and after pregnancy?
Prior to pregnancy, it is small, almost solid pear shaped organ, weighing approximately 2 ounces
By the end of the pregnancy, it will reach an average weight of 2.5 pounds
Uterine capacity increases from 10mL in the non-pregnant state to roughly 5000mL at term
How does the circulatory needs of the uterus change during pregnancy?
Circulatory needs of the uterus increases as the uterus enlarges and the fetus and placenta develop
By the end of a term pregnancy, 1/6 of the total maternal blood volume is contained with within the vascular system of the uterus
What are Braxton Hicks contractions?
Painless, irregular uterine contractions
“False labour”: Does not cause cervical dilation
What is the purpose of Braxton Hicks contractions?
Their purpose is to stimulate blood flow through the intervillous spaces of the placenta
What is Goodwells sign and Chadwick’s sign?
Goodwells sign: cervical softening
Chadwick’s sign: blue purple discolouration of the cervix
What is the pregnancy hormone?
Human Chorionic Gonadotropin (hCG)
What does hCG do?
Maintains the corpus luteum, which:
Secretes progesterone to maintain the endometrium until the placenta takes over
Disintegrates when placenta is fully functioning, about 6-8 weeks
What is the precursor for breast milk?
Colostrum
How does the vagina change during pregnancy?
Estrogen facilitates hypertrophy (increase in size of cells), hyperplasia (increase in number of cells), and increase vascularization of vaginal epithelium
Mucosa thickens, connective tissue loosens, and secretion’s increase
What are vaginal secretions?
Secretions are thick, and acidic and helps play a role in preventing infections
How does the respiratory system change due to pregnancy?
Between 16 and 40 weeks, oxygen consumption increases 15-20%
Diaphragm is elevated as a result of the growing uterus
Breathing changes from abdominal to thoracic
Nasal stuffiness/ congestion and nose bleeds due to increased estrogen induced edema and vascular congestion of nasal mucosa
Patient teaching for shortness of breath
Rising uterus puts pressure on diaphragm so teach patient:
Sit up straight in chair
Use proper posture when standing
Prop head up while sleeping
How does blood volume change during pregnancy?
Blood volume progressively increases and peaks at the middle of the third trimester at about 40 to 50% over non-pregnant levels (meaning it doubles)
Decrease in systemic vascular resistance, which enable circulation to adapt to higher blood volume
How does cardiac output change during pregnancy?
Cardiac output, which is the amount of blood discharged from ventricles per minute increases and peaks by 25 to 30 weeks gestation, then remains elevated throughout pregnancy
How do vital signs change during pregnancy?
Pulse can increase 10 BPM
Blood pressure decreases slightly, and reaches lowest point in second trimester
What happens to femoral venous pressure during pregnancy?
It rises as a result of increased uterine pressure
What is supine hypotensive syndrome?
AKA: vena caval syndrome
The enlarging uterus may put pressure on the vena cava when the woman is supine, causing a decrease in blood pressure with accompanying dizziness, pallor, and clamminess
What is physiologic (or dilutional) anemia?
Due to the plasma volume increase being greater than the erythrocyte increase, the hematocrit decreases slightly
Plasma volume increases 50%
What is the importance of iron?
Iron is necessary for hemoglobin production
Hemoglobin is the oxygen carrying component of the erythrocytes
Iron absorption increases in pregnancy, but supplements are usually still necessary
Why does nausea and vomiting happen in first trimester?
Increase levels of hCG
Stomach smooth muscle relaxation
Slowed peristalsis
Usually decreases by the 16th week
What the normal weight gain for pregnancy?
Normal weight: 25-35 pounds
Over weight: 15-25 pounds
Obese: 11-20 pounds
Underweight: 28-40 pounds
What are some of the common discomforts of pregnancy?
Fatigue
Round ligament pain
Low back pain
Upper back pain
Urinary frequency
Hemorrhoids
Constipation
Importance of oxytocin in pregnancy?
Oxytocin affects uterine contractibility and milk ejection from breasts
Released during times of bonding - makes you feel good
Synthetic oxytocin is called pitocin and it is used for induction and augmentation of labour
Treats postpartum hemorrhages
Importance of hCG in pregnancy
Secreted by trophoblast in early pregnancy
hCG stimulates progesterone and estrogen production by the corpus luteum until placenta takes over
What is human placental lactogen (hPI)?
Insulin antagonist: decreases maternal metabolism of glucose to favor fetal growth
It increases amount of circulating free fatty acids from maternal metabolic needs
It is a player in the development of gestational diabetes
Importance of estrogen during pregnancy
Initially produced by corpus luteum then placenta takes over at around seventh week
Stimulates uterine growth
Develops ductal system of breasts to prepare for lactation
What is considered the most crucial hormone in maintaining pregnancy?
Progesterone
How is progesterone produced?
Initially produced by corpus luteum then by placenta
Why is progesterone so important in pregnancy?
Maintains endometrium
Inhibits spontaneous uterine contractility
Develops breast for lactation
Importance of relaxin during pregnancy?
Primarily produced by corpus luteum, then in small amounts by placenta and decidua
Inhibits uterine contractibility
Relaxes joints/ligaments
Aids in cervical ripening
How is nasal stuffiness a pregnancy discomfort?
Estrogen engorged mucus membranes.
Increased nasal discharge
What are nasal stuffiness teachings?
Ocean spray, nasal spray/cool air vaporizer
Do not use nasal decongestants (afrin) for longer than three days
How are varicose veins caused?
Weak vein walls, or faulty valves
Enlarge uterus impairs venous circulation
Familial tendency, prolonged sitting/standing
Progesterone relaxes blood vessel walls
Excessive weight gain, advanced maternal age
Patient teachings for varicose veins
Exercise and good body mechanics
Support hose
Elevate legs every 2 to 3 hours to hip level.. or if possible elevate to heart level
Teachings for difficulty sleeping
It’s a common occurrence
Often related to other physical factors
Suggestions for difficulty sleeping?
Warm, caffeine free beverage before bed
Back rub
Relaxation techniques
Pillow support for back/legs
What are the signs of pregnancy?
The 3Ps
Subjective (presumptive) comes from the patient “I think”
Objective (probable) comes from us, we see signs
Diagnostic (positive) an outside source like an ultrasound
What are probable (objective) changes perceived by the examiner?
Positive pregnancy test (hCG)
Changes in pelvic organs
Goodells sign- softening of cervix
Chadwick’s sign- deep red to
purple/blue
coloration of cervix,
mucus membranes,
and vagina
Hegar’s sign- softening of the
isthmus of the cervix
Uterine soufflé: soft blowing sound at the same rate as maternal pulse, due to increase vascularization, and blood pulsating through the placenta
Changes in skin pigmentation
What are some positive (diagnostic) signs determined by the examiner?
Fetal heartbeat
Fetal movement
Visualization of fetus by ultrasound
