Physiology pregnancy

Question 1

Resp changes

Answer 1

Increase minute ventilation 50% - tidal volume rise, RR unchanged
Reduce functional residual capacity
Increase vital capacity - soften ligament
PaCO2 decrease - resp alkalosis

Question 1

Cardiac changes

Answer 1

Increase CO by 40% - HR & SV increase, labour x2 fold - cathecholamines , further 20% rise 1hr post delivery - autotransfusion
Decrease peripheral vascular resistance - vasodilation, BP nadir mid pregnancy.
Increase LL venous pressure - mechanical compression
Increase flow to uterus & kidney

Question 2

Renal

Answer 2

Increase kidney size
Increase blood flow, GFR rise by 50%
Tubular - increase pore size glycosuria, proteinuria
Increase RAAS - Na/H2O , Vit D & EPO production

Question 3

Hormonal

Answer 3

T1 - CL dependent release E+P
bhcg detection D8, peak 10/40
Placenta taken over
- EP rise throughout, fall post delivery
E breast & uterine growth, pelvic ligament relax
P maintain endometrium, relax uterus inhbit contraction, mammary glands growth
- hPL decrease insulin sensitivity increase glucose supply
- Relaxin relax CT, shorten cervix pre labour

Question 4

Haem

Answer 4

Increase blood volume 40%
RBC increase - but dilutional anaemia
Composition change
- rise WCC
- dilutional low protein -> oedema due to decrease colloid osmotic pressure
- hypercoagulability -> rise fibrinogen, clotting factors, reduce ATIII

Question 5

GIT

Answer 5

N+V 2nd hcg
Decrease gut motility
Impair gallbladder contraction
Reduce E sphincter pressure

Question 6

Metabolic

Answer 6

increase metabolic rate
Fatty acid use as main energy source
Insulin resistance -> low glycogen store -> risk of ketosis

Question 7

Immunity

Answer 7

Humoral > Cell mediated tolerate fetal antigen better
Reduce new infection clearance

Question 8

Endocrine

Answer 8

hcg same alpha subunit as TSH - T1 transient increase
Increase iodine, thyroid hormone production

CRH increase in late pregnancy -> cortisol for lung maturation & surfactant production

Question 9

Skin

Answer 9

Abdominal striae
Hyperpigmentation - increase melanocyte stimulating hormone -> linea alba, cholasma chloasma
Increase androgen -> acne, hirsutism

Question 10

Breast

Answer 10

E promote duct growth + breast size
P alveolar lobular development
Prolactin - pp sudden rise increase lactogenesis
Oxytocin - suckling result in contraction & ejection