Maternal Changes in Pregnancy ☺️

Question 1

Why does your weight increase

Answer 1

Increases by 13kg

• baby
• uterus, placenta, amniotic fluid
• breast enlargement
• increase in blood, fluid volume
• increased fat reserve

Question 2

Resp changes

• ventilation
• RR
• TV
• PO2, PCO2
• pH, HCO3-
• diaphragm, ribcage

Answer 2

Ventilation increases
RR no change
TV increases (P on resp center)
PO2 increases
Overbreathing => PCO2 fall, remove extra fetal CO2
HCO3 decreases (increased CO2 buffering)
pH resp alk compensation possible
Diaphragm moves up as uterus moves up
Ribcage moves up and expands to the side

Question 3

CV changes

• HR
• CO
• SV
• systolic, diastolic BP

Haemodynamic changes

• BV
• RBC, haematocrit, O2 loading
• platelet and coagulation
• WBC
• [lipid]
• [water]

Answer 3

HR increases
CO increases
SV increases
systolic BP no change
diastolic BP falls (P VD)

BV increases
RBC increases, haematocrit falls due to haemodilution
O2 loading increases (higher DPG)
Platelets decrease
Coagulation increases, fibrinolytic decreases
WBC increases
[lipid soluble molecules] increases, especially TAGs for growth
[water soluble molecules] deacreases due to haemodilution
-folate actively used

Question 4

Regional flow of blood

• uterus, kidney, skin
• skin
• other

Answer 4

Uterus, renal increases

Skin increases in extremities => increased nail, hair growth, nosebleeds, stuffiness, no Raynauds

Other
-decreases

Question 5

How does the renal system change

• GFR
• Na, water uptake
• [urea, creatinine]
• urinary retention

Answer 5

GFR increases, excrete fetal waste
Na, water uptake increased
-maintain PV
[urea, creatinine] decreased due to increased GFR
Urinary retention increases (P SM relax)
Urinary frequency increases
-GFR increases and uterus pushes on bladder

Question 6

GI system

• sphincter tone
• motility

Answer 6

Sphincter tone decreases
-reflux
Motility decreases
-constipation, increased nutrient uptake

Question 7

Oestrogen

• source
• function

Answer 7

Ovaries, placenta, blood

• myometrial growth
• breast growth

Question 8

Progesterone

• source
• function

Answer 8

Syncitiotrophoblast produces bhCG => corpus luteum produces P
Placenta starts production at 6 weeks, takes over at 12 weeks

Inhibits uterine contractions by

1. Inhibiting prostaglandin production
2. Decreasing sensitivity to oxytocin, allows for development of lobules and alveoli

Question 9

hCG

• source
• function

hPL

• source
• function

Leptin
-function

Placental growth factor
-function

Answer 9

Syncytiotrophoblast => maintain CL until wk7
Stimulate TSH receptors => increase thyroid activity

Syncytiotrophoblast
Maternal lipolysis, diabetogenic => increase FFA, glucose for fetus

Stimulate AA, FA transport in placental
Aid placental survival

Angiogenesis

Question 10

Prolactin

-function

Answer 10

Increases in pregnancy due to O increase

• initiates, maintains milk secretion
• needed for expression of mammotropic effects of O, P
• O, P directly antagonse effects of PRL on milk synthesis