Pregnancy

Question 1

describe hCG

Answer 1

• glycoprotein
• secreted by syncytial cells of trophoblast
• prevents involution of corpus luteum
• used in pregnancy tests

Question 2

describe what the corpus luteum produces

Answer 2

• estrogens
• progesterone
• relaxin
  
  • relaxes pelvic ligaments

Question 3

describe function of hCG in male fetus

Answer 3

• stimulates testosterone production
• promotes descent of testes

Question 4

describe the timeline of corpus luteum and placenta

Answer 4

• up to week 12:
  
  • corpus luteum produces progesterone
• more than 12 weeks
  
  • placenta fully developed
  • takes over role of hCG and produces progesterone
  • corpus luteum involutes

Question 5

describe role of progesterone in fetus

Answer 5

• progesterone is an important precursor for synthesis of adrenocortical hormones by fetal adrenal cortex
  
  • DHEA-S is produced in fetal adrenal gland which is then made into estrone/estradiol
  • estradiol is resent to fetal liver to make 16-DHEA-S which goes back to placenta to make estriol

Question 6

describe the role of progesterone in the mother

Answer 6

• maintains pregnancy
• supports endometrial lining
• forms cervical plug
• makes uterus < excitable as it expands (inhibits labor)
• inhibits lactation during pregnancy

Question 7

describe function of estrogen in mother

Answer 7

• prepares body for parturition
• inhibits milk production
• development of breast
• initiation of labor (increased estrogen:progesterone ratio)
• increases levels of all binding globulins
  *

Question 8

describe the role of estrogen in the fetus

Answer 8

• placenta has strong aromatase activity which convert androgens to estrogens which prevents masculinization of female fetus

Question 9

describe role of hPL

Answer 9

• major role is to make glucose available for fetus
• releases FFA stores and inhibits uptake of glucose in the mother
• breast development
• secreted by the placenta

Question 10

describe endocrine changes in pregnancy in the mother

Answer 10

• AP size increases by 50%
  
  • ACTH and prolactin increase
  • FSH and LH decrease
    
    • ​decreases because of high estrogen/progesterone levels from fetus that negatively feedback on GnRH

Question 11

describe change in thyroid gland in pregnant mother

Answer 11

• thyroid gland increases by 50% because of increased TSH, hCG, and hCT
  
  • increase in total T3 and T4
• the mother is still euthyroid because of elevated levels of TBG, not hyperthyroid

Question 12

describe change in parathyroid gland in preg. mother

Answer 12

• increase in PTH
  
  • increases Ca for fetus
  • increases Ca for milk after birth

Question 13

describe change in pancrease in preg. mother

Answer 13

• pancreas increases production of insulin
  
  • insulin resistance in mother’s tissues in order to make more glucose available for the fetus

Question 14

describe change in adrenal gland in preg. mother

Answer 14

• increases cortisol levels
  
  • AAs for fetus
  • weight gain
  • only moderate rise in cortisol due to increase in CBG
• increases aldosterone
  
  • increases CO (high O2 needs for herself and fetus)
• increase in DHEA-S
  
  • estrogen production by placenta

Question 15

describe changes in fetal thyroid gland and parathyroid gland

Answer 15

• increase in thyroid hormone helps in somatic growth
• increase in calcitonin helps with bone formation
• decrease in parathyroid gland since PTH secretion is unwanted –> fetus needs Ca to be used for bone formation