Maternal Adaptation to Pregnancy

Question 1

what secretes hCG and what is its function

Answer 1

it is secreted by the synctiotrophoblast layer (outer layer of the blastocyst) after implantation

maintains the CL which secretes oestrogen and progesterone to maintain the pregnancy for about 10 weeks

after this the placenta takes over

Question 2

what secretes hPL

Answer 2

again the synctiotrophoblast layer of the blastocyst

Question 3

what does hPL do

Answer 3

modifies maternal metabolism so there is more energy for the foetus - decreased insulin sensitivity in the mother to raise blood glucose levels so there are more for the foetus

Question 4

what happens to CO, HR and SV

Answer 4

all increase

CO to 30-50% above normal

Question 5

outline the changes in blood pressure that occur

Answer 5

diastolic BP decreases in the 1st and 2nd trimester due to changes in circulation: vessels dilate, increased PV, uteroplacental circulation

increases to pre pregnancy levels by term

Question 6

outline the haematolgoical changes that occur

Answer 6

plasma volume increases proportionally to CO (30-50%)

eythropoeisis also increases, but less

= haemodilution

Question 7

outline the respiratory changes during pregnancy

Answer 7

TV and minute volume increase but vital capacity is unchanged

TLC (FRC) is reduced as the diaphragm is elevated by the uterus

Question 8

outline the urological changes in pregnancy

Answer 8

due to the increase in PV and CO, renal plasma flow and GFR is increased = increased urinary output

as a result, increased excretion of urea, creatinine and protein = decreased serum urea and creatinine and increased urinary protein