Exam 3 - Anatomic and Physiologic Adaptations to Pregnancy Flashcards
Cardiovascular changes during pregnancy
- Increased CO, SV, HR, BP, blood volume, blood flow to uterus
- Decreased SVR
Metabolic changes during pregnancy
- Increased protein content, fat deposits, blood lipids, salt accumulation, body weight
- Water retention
Respiratory changes during pregnancy
- Increased tidal volume, VO2
- Impaired ventilation (rise in diaphragm)
Musculoskeletal system changes during pregnancy
Increased joint laxity, risk of sprains and strains
Endocrine changes during pregnancy
Increased LH, growth hormone, human placental lactogen, estrogen, progesterone
What are the four functions of the placenta?
- Respiratory organ for gas exchange
- Metabolizes and synthesizes agents needed to sustain pregnancy
- Provides protective immunologic barrier
- Releases hormones, growth factors, etc.
What are the four main hormones secreted by the placenta?
- hCG
- Human placental lactogen
- Estrogen
- Progesterone
Where is hCG secreted before it is secreted by the placenta?
hCG is secreted by the blastocyst early in developing embryo before implantation, then secreted by placenta
What is the role of hCG during pregnancy?
- Sustains the corpus luteum
- Aid in the production of progesterone and estrogen
How long is hCG secreted for before the placenta secretes the other four hormones?
Secreted until 8-10 weeks, then placenta takes over to produce estrogen and progesterone
When is hCG detected in maternal serum and urine?
- 7-8 days after ovulation
- Levels get to 100,000 at 8-12 weeks gestation
- Levels double every 48-72 hours, plateaus, then decreases and stablizes at 20,000
- 60-90 days after LMP
When will pregnancy tests show up positive?
Positive 3 weeks after conception or 5 weeks after LMP
In what situations would women have higher and lower hCG levels?
Higher with multiple pregnancies, molar pregnancy
Low with ectopic pregnancy, abnormal implantation
What hormone is correlated with N/V during the first trimester?
Rise and fall of hCG
What is the role of human placental lactogen?
Alters maternal protein carbohydrate and fat metabolism
- Increases in maternal plasma fatty acids and triglycerides making them available as energy for pregnant woman
- Causes maternal insulin resistance –> reduces maternal glucose uptake, creates reserves of maternal glucose for fetus
When does the pregnant woman start making glucose?
Just before birth - will start making glucose and amino acids for fetal development
Where is estrogen secreted from during pregnancy?
Secreted early on by corpus luteum, then later from the placenta
What is the primary form of estrogen during pregnancy?
Estriol
Where in the fetus are metabolites processed?
Processed by adrenal gland and liver –> adrenal gland makes DHA and sulfa conjugate (ingredients for estrogen) –> sent back to placenta to make estriol
Where is progesterone secreted during pregnancy?
Corpus luteum and placenta
What are the functions of progesterone during pregnancy?
- Prepares and maintains secretory activities of uterine decidual tissue needed for implantation
- Maintains quiescent state in myometrium
- Utilizes smooth muscle relaxing abilities
- Acts on venous walls to accomodate increase in blood volume
- Promotes mammary growth in lobules for lactation
Where is relaxin secreted during pregnancy?
Corpus luteum, then uterus, then placenta
What are the functions of relaxin during pregnancy?
- Prepares endometrial decidual tissue for maintanence of early pregnancy
- Inhibits uterine activity during pregnancy
- Softens ligaments resulting in minor instability of sacroiliac, sacrococcygeal, and pubic joints to facilitate birth and widens pelvis
