Exam 3 - Maternal Adaptations of Pregnancy Flashcards
How long is the human gestation period?
266 days (38 weeks) since ovulation
- 10 lunar months, 9 calendar months
Musculoligamentous changes to the woman during pregnancy
- Lordosis and accentuated lumbosacral spinal curve
- Change in posture from center of gravity
- Kyphosis
- Altered gait
- Pubis symphysis widens
- Pelvis tilts anteriorly
- Separation of rectus abdominis due to pressure from enlarged uterus –> diastasis recti
Integumentary changes to pregnant women
Estrogen and progesterone + melanocyte stimulating hormone induces melanocytes to deposit pigments in skin
What causes striae gravidarum during pregnancy?
From thinning of elastin fibers and collagen in connective tissue
- Stretching and softening in epidermal junction under skin
Nail changes to pregnant women
- Transverse grooving
- Softening
- Increased brittleness
Hair changes to pregnant women
- Increase in number of hairs in growth phase
- Decrease in number of hairs in resting phase
- Longer and thicker hair
Will reverse postpartum - hair loss 2-4 months after delivery
Cardiovascular changes in pregnant women
- HR increases in first month and peaks at 32 weeks
- Ventricular muscle mass increases
- Heart displaced upward, forward, to left
Can murmurs be heard during pregnancy?
Systolic murmur heard between 12-20 weeks
- S1, S2 split can happen and/or S3
- Murmurs louder than 2 out of 6, or any diastolic murmur, requires eval
Does blood volume increase during pregnancy?
Increases as early as 6 weeks and peaks at 32 weeks
- Due to increased plasma volume and red cell mass (RBC volume)
- Hemodilution –> decrease in hemoglobin
Why is there an increase in blood volume during pregnancy?
- Maintains adequate blood flow to uterus, fetus, maternal tissues
- Maintains BP and regulates temperature
- Prepares for blood loss during delivery
What cardiovascular changes occur during the second and third trimester of pregnancy?
- Hemoglobin and hematocrit levels drop in late pregnancy
- Due to fetal uptake which maternal reserves cannot replace
- Iron absorption improved in pregnancy but not enough to account for difference so mothers reserves are depleted
How does blood pressure change during pregnancy?
Decreases from pre-pregnancy levels and reaches low in second trimester –> returns to baseline in third trimester
- Can decrease in left lateral position
- Due to hormonal effects of vasodilation and decreased SVR
True/false: Pregnancy is considered a hypercoagulable state
True - increased clotting factors, decreased fibrinolysis, decreased anticoagulant activity
- Protective changes to prevent hemorrhage at birth
- Increases risk for VTE and coagulopathies during pregnancy and immediate postpartum period
Is there increased leukocyte production in pregnancy?
Yes, may rise to 6,000-17,000 in third trimester without infection
- Normal: 4,000-12,000
What are the anatomic changes to the respiratory organs during pregnancy?
- Diaphragm rises from upward uterine pressure
- Lung chamber expands AP diameter to compensate and improve lung capacity
Allows for sufficient gas exchange to meet maternal and fetal metabolic needs
How does respiration change during pregnancy?
- Tidal volume increases
- Minute ventilation and CO increase
- RR unchanged
- Tachypnea sign of possible respiratory compromise
What is the overall effect of hyperventilation on the pregnant woman?
State of compensated respiratory alkalosis –> improves carbon dioxide transfer from fetus to mother
What are renal system changes that occur due to hematologic changes?
Increased CO and arterial vasodilation –> renal blood flow increases in first and second trimester
- Increased urine flow and output
Is the reabsorption of glucose and proteins good during pregnancy?
Reabsorption of glucose and protein not efficient in pregnancy –> occasional glycosuria or proteinuria
- Serum glucose levels should be monitored
- 24 hour urine >300 mg of protein signals issue
What influence does progesterone have on the renal system?
Causes dilation of ureters, urethra, bladder –> urinary stasis
- Increased risk of UTI
What GI changes can occur during the second month of pregnancy?
- Gingival edema
- Hyperemia
- Bleeding gums
Due to increased vascularity and blood flow, connective tissue changes, inflammatory mediators
Does the lower esophageal sphincter tone increase or decrease during pregnancy?
Lower esophageal sphincter tone decreases due to progesterone effects
- Enlarging uterus pushes stomach and intestines up, moving them into thorax
- Heartburn and reflux
What hormones have been associated with N/V during pregnancy?
Estrogen and hCG
- Cause/mechanism unclear
Changes to the uterus during pregnancy
- Grows from pear shaped organ weighing 60 g to elongated globular cylinder shape weighing 800-1200 g
- Myometrium for contractility and elasticity –> allows for lengthening, shortening, and ability to stretch creating forces of labor
What happens to the uterus during third trimester?
Uterine muscle wall thins allowing for easier palpation of growing fetus
What is the role of mucus plugs?
Cervical glands produce mucus plug to prevent bacteria from entering uterine cavity
When is the mucus plug expelled?
Mucus plug expelled prior to onset of labor or in conjunction with onset of labor
- Can be confused with vaginal leaking of fluid or bloody show
What hormones cause weakening of the cervix?
Before labor, collagen becomes disorganized on cervix
- Low progesterone and high estrogen cause mechanical weakening
Prostaglandin activity also helps with cervical dilation
Changes related to the ovaries during pregnancy
- Ovulation stops
- Corpus luteum continues secreting progesterone for 10-12 weeks to maintain endometrium until placenta can assume the production and secretion of hormones
What vaginal adaptations occur to the vagina during pregnancy?
- Increased vascularization, hypertrophy, hyperplasia
- Connective tissue loosens
- Mucosa produces vaginal secretions (prevent infection)
- Vaginal walls and perineal body become relaxed –> stretch and accomodate birth
