Exam 3 - Anatomic and Physiologic Adaptations to Pregnancy

Question 1

Cardiovascular changes during pregnancy

Answer 1

• Increased CO, SV, HR, BP, blood volume, blood flow to uterus
• Decreased SVR

Question 2

Metabolic changes during pregnancy

Answer 2

• Increased protein content, fat deposits, blood lipids, salt accumulation, body weight
• Water retention

Question 3

Respiratory changes during pregnancy

Answer 3

• Increased tidal volume, VO2
• Impaired ventilation (rise in diaphragm)

Question 4

Musculoskeletal system changes during pregnancy

Answer 4

Increased joint laxity, risk of sprains and strains

Question 5

Endocrine changes during pregnancy

Answer 5

Increased LH, growth hormone, human placental lactogen, estrogen, progesterone

Question 6

What are the four functions of the placenta?

Answer 6

• Respiratory organ for gas exchange
• Metabolizes and synthesizes agents needed to sustain pregnancy
• Provides protective immunologic barrier
• Releases hormones, growth factors, etc.

Question 7

What are the four main hormones secreted by the placenta?

Answer 7

• hCG
• Human placental lactogen
• Estrogen
• Progesterone

Question 8

Where is hCG secreted before it is secreted by the placenta?

Answer 8

hCG is secreted by the blastocyst early in developing embryo before implantation, then secreted by placenta

Question 9

What is the role of hCG during pregnancy?

Answer 9

• Sustains the corpus luteum
• Aid in the production of progesterone and estrogen

Question 10

How long is hCG secreted for before the placenta secretes the other four hormones?

Answer 10

Secreted until 8-10 weeks, then placenta takes over to produce estrogen and progesterone

Question 11

When is hCG detected in maternal serum and urine?

Answer 11

• 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

Question 12

When will pregnancy tests show up positive?

Answer 12

Positive 3 weeks after conception or 5 weeks after LMP

Question 13

In what situations would women have higher and lower hCG levels?

Answer 13

Higher with multiple pregnancies, molar pregnancy

Low with ectopic pregnancy, abnormal implantation

Question 14

What hormone is correlated with N/V during the first trimester?

Answer 14

Rise and fall of hCG

Question 15

What is the role of human placental lactogen?

Answer 15

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

Question 16

When does the pregnant woman start making glucose?

Answer 16

Just before birth - will start making glucose and amino acids for fetal development

Question 17

Where is estrogen secreted from during pregnancy?

Answer 17

Secreted early on by corpus luteum, then later from the placenta

Question 18

What is the primary form of estrogen during pregnancy?

Answer 18

Estriol

Question 19

Where in the fetus are metabolites processed?

Answer 19

Processed by adrenal gland and liver –> adrenal gland makes DHA and sulfa conjugate (ingredients for estrogen) –> sent back to placenta to make estriol

Question 20

Where is progesterone secreted during pregnancy?

Answer 20

Corpus luteum and placenta

Question 21

What are the functions of progesterone during pregnancy?

Answer 21

• 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

Question 22

Where is relaxin secreted during pregnancy?

Answer 22

Corpus luteum, then uterus, then placenta

Question 23

What are the functions of relaxin during pregnancy?

Answer 23

• 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