Physiology of Pregnancy

Question 1

what happens to cardiac output in pregnancy?

Answer 1

• increases from week 6 and peaks at week 24
• decreases in the last 8 weeks of pregnancy
• increases again during labour

Question 2

what happens to heart rate during pregnancy?

Answer 2

increases

Question 3

what happens to BP during pregnancy?

Answer 3

drops during the 2nd trimester due to expansion of uteroplacental circulation

Question 4

respiratory adaptations to pregnancy?

Answer 4

respiratory rate increases

tidal and minute volumes increase

PCO2 decreases

PO2 and vital capacity stay the same

Question 5

what happens to haemoglobin during pregnancy?

Answer 5

reduces - as a result of increased plasma volume - causing haemo-dilution

• iron requirement increases

Question 6

what are the urinary adaptations of pregnancy?

Answer 6

• GFR increases
• renal plasma flow increases
• re-absorption of ions and water increases

Question 7

when is the process of implantation complete?

Answer 7

day 12 after fertilisation

Question 8

what is the placenta derived from?

Answer 8

a combination of maternal endometrial cells and the trophoblast.

Question 9

functions of the placenta?

Answer 9

• secretes progesterone and HCG
• gas exchange
• nutrient and waste exchange (calcium and iron are the only 2 electrolytes that can only travel unidirectional from mother to baby)
• transfer of IgG

Question 10

at which gestational age do levels of HCG increase and peak at?

Answer 10

10 weeks

Question 11

actions of oestrogen?

Answer 11

• enlargement of the uterus
• development of breasts
• relaxation of the pelvic ligaments

Question 12

actions of progesterone?

Answer 12

• prepare and maintain the endometrium
• decrease uterine contractions