Module 6: Physiologic Adaptation To Pregnancy

Question 1

Physiologic Changes in Pregnancy

Answer 1

1. Increased metabolic demands
2. Support for developing fetus
3. Preparation for physical demands of birth and lactation
4. Understanding the expected changes of pregnancy assist in recognition of pathologic changes

Question 2

Hormones that Influence Maternal Adaptation to Pregnancy

-HcG

Answer 2

1. Thyroid stimulation
2. Vasodilation & relaxation of uterus
3. Secretion of relaxin

Question 3

Hormones that Influence Maternal Adaptation to Pregnancy

-Human Placental Lactogen

Answer 3

1. Lipolysis
2. Increwased insulin resistance
3. Angiogenesis
4. Lipid synthesis

Question 4

Hormones that Influence Maternal Adaptation to Pregnancy

-Corticotropin Releasing Hormone

Answer 4

1. Maternal immunosupporession

2. Smooth muscle relaxation of blood vessels and uterus

Question 5

Hormones that Influence Maternal Adaptation to Pregnancy

-Relaxin

Answer 5

1. Remodels collagen

2. Affects cartilage of skeletal system

Question 6

Hormones that Influence Maternal Adaptation to Pregnancy

-Estrogen

Answer 6

1. Uterine vasodilation
2. Stimulate phospholipid synthesis
3. Increases prostaglandin production

Question 7

Hormones that Influence Maternal Adaptation to Pregnancy

-Progesterone

Answer 7

1. # 1 Hormone TEST
2. Quiets uterus
3. Smooth muscle relaxation
4. Increases maternal temperature
5. Inhibits maternal cell-mediated immune function
6. Decreases CO2 sensitivity

Question 8

Vital Sign Changes in Pregnancy

Answer 8

1. Heart Rate Increases by 15-20 BPM by 32 weeks EGA
2. Blood Pressure
   - Decreases in 1st and 2nd trimester and returns to pre-pregnancy in 3rd trimester
   - May increase with sitting, Decrease with left lateral/side lying position
3. Respiratory rate increases 1-2 breaths/minute

Question 9

Cardiovascular System Changes

Answer 9

1. Heart is displaced upward — Louder heart sounds w/ S3 becoming common and wide splitting of S1
2. Systolic ejection murmur and mammary souffle d/t increased plasma volume
3. Cardiac output increases 30-50%
   - Cardiac dz may become symptomatic as early as 1st trimester
   - Supports increased oxygen consumption
   - Reduced systemic vascular resistance and SBP
4. Supine hypotention, Syncope
   - Gravid uterus increases risk for inferior vena cava and aortic compression w/ supine position

Question 10

Vascular Changes in Pregnancy

Answer 10

1. Decrased vascular resistance
   - Softer Collagen, Vasodilation
   - Arterial relaxation, decreased peripheral vascular resistance
2. Slowed venous flow — Increased stasis of the blood
   - Increased risk of DVT’s
3. Hemmerhoids and varicosities in lower extremities and vulva

Question 11

Hematologic Changes in Pregnancy

Answer 11

1. Blood volume incrases 50% by 28 wks — Woman has double the circulating blood volume as pre pregnancy by 3rd trimester - 1,600 ml’s
   - Improves blood flow to vital organs
   - Protects agains excessive blood loss w/ birth
   - Increased pre-load
2. Hemodilution
   - Physiologic anemia of pregnancy
   - Hgb and Hct decreased — most likely in 2nd and 3rd trimester
3. Hypercoagulable state
   - Increased clotting factors, increased risk DVT — Increased during post birth period

Question 12

Respiratory System Changes in Pregnancy

Answer 12

1. Reduced lung capacity
   - Uterus compresses diaphragm leading to increased diameter of thorax — Sideways inflation instead of down
   - FEV1 is stable
   - Total lung capacity drops slightly
2. Respiratory congestion possible from increased edema of pharynx and larynx
3. 30% increase in oxygen consumption may compromise respiratory function in clients w/ chronic asthma, obesity or smoking
4. Reduced exercise tolerance, felling of breathlessness — Innocent hyperpnea

Question 13

GI Changes in Pregnancy

Answer 13

1. Decreased Intestinal Contractility — Flatus, constipation
2. Displacement of abdominal organs — Dyspepsia (Progesterone)

Question 14

Renal System Changes in Pregnancy

Answer 14

1. Kidnesy are displaced and increase in size — 50% increase in renal blood flow
2. Increased GFR
   - DIlation of ureters and renal pelvis (Physiologic hydronephrosis)*
3. Progesterone leads to decrased bladder tone
   - Urinary Frequency
   - Urinary Incontinence
4. Increase risk of COMPLICATED UTI — ALL UTI’s are complicated in pregnancy women for RISK of PYLONEPHRITIS

Question 15

Integumentary System Changes in Pregnancy

Answer 15

1. Breakdown of Connective Tissue — Stretch marks aka striae gravidarum
2. Increased melanocyte stimulating hormone
   - Linea nigra
   - Melasma — Use sunscreen through pregnancy
3. Estrogen
   - Hair growth, thickness (estrogen induced)
   - Hair loss post-birth

Question 16

Musculoskeletal System Changes in Pregnancy

Answer 16

1. Progestrerone, Estrogen, and relaxin cause ligaments and joints to RELAX and loosen in the pelvid structures
2. Posture — Shifting center of balance caused by enlarging uterus
3. Gait Changes
   - Sciatica, discomfort of the symphysis pubis
   - Stretching/pain of uerosacral and cardinal ligaments (Rubber bands that hold uterus in place) are all common.

Question 17

Endocrine/Metabolic System Changes in Pregnancy

Answer 17

1. Mild enlargement of thyroid
2. Basal metabolic rate increases 20-25%
3. Progressive insulin resistance as pregnancy progresses
   - Risk of gestational diabetes
   - Pre-gestational diabetes requires aggressive managment in adjustments in medications
4. Lipolysis
   - Increased serum cholesterol, triglycerides, lipoproteins
   - Do not check lipid levels during pregnancy

Question 18

Immune System Changes in Pregnancy

Answer 18

1. The fetus is a semi-allograft (Considered a foreign body from males side)
2. Cell mediated immune response is suppressed
3. Inflammatory markers may be increased (CRP, ESR, Compliment factors)
4. Maternal IgG can cross placenta which may affect newborn
   - Graves disease - can cross into fetus
   - Myasthenia gravis - can cross into fetus
   - Rhesus incompatibility - Difference in Rh factor
5. Immune system changes can influence
   - Spontaneous abortion
   - Preterm birth
   - Susceptibility to infection (COVID/Influenza)

Question 19

Neurologic System and Psychosocial Changes in Pregnancy

Answer 19

1. Emotional lability and irritability
   - Shifting hormone levels + impending change (situational mood alterations)
   - Sleep alterations increase risk of mood changes/exacerbations
2. Cognition
   - Decreased attention span, concentration, and memory lapses “pregnancy brain”
3. Optic CHanges
   - Corneal edema, decreased intraocular pressure — ACUTE VISUAL CHANGES are NOT NORMAL **
   - Resolves after birth