physiology of pregnancy Flashcards
What are 3 main hormones involved in pregnancy
BHCG- dramatic rise in the first days-weeks- released from the corpus luteum initially, then by placenta
progesterone- e.g. pro-gestation- keeps the state of quiescence
oestrogen- breast growth, areolar enlargement
What is the role of HCG, what is the clinical relevance of large quantities of HCG?
Maintains corpus luteum secretion of prog % oest, decreases as placenta develops and prog increases.
large quantities released in molar pregnancy and multiple pregnancies
What is the role of progesterone in pregnancy
relaxes smooth muscle, maintains uterine dormancy via decreasing uterine electrical activity,
lobulo-alveolar development in breasts
What is the role of oestrogen
Growth of the uterus, cervical changes,
development of the ductal system of breasts
stimulation of prolactin synthesis.
alongside hCG the placenta produces hPL and hPG
what is the role of hPL
hPL (human placental lactogen)- alters maternal carbs and lipids to provide a steady state of glucose for fetal requirements.
alongside hCG the placenta produces hPL and hPG
what is the role of hPG
hPG (human placental gonadotrophin) induces insulin resistance to regulate fetal growth- this may become a pathological process seen as GDM
What effects does pregnancy have on the haematological system
40% increase in plasma volume, 25% increase in RBC
increased clotting factors- hypercoagulable state.
What effects does pregnancy have on the cardiovascular system
Increased blood volume implications:
- cardiac output increase
- peripheral resistance decrease
- blood pressure
the heart is working harder to reach the supply demands of the fetus- increased HR and SV to account for increased CO.
heart hypertrophies by 12%
what is the effect of pregnancy on peripheral vascular resistance?
Peripheral vasodilation (effects of progesterone)
peripheral resistance decreased by 35%
combined with increased CO results in slightly lower BP
decreased resistance means lower BP.
Clinical aspects of the changes in pregnancy
increased ventilation- the sensation of SOB
raised HR leads to palpitations
lots of cross over with PE symptoms
excess plasma volume shifts causing peripheral oedema
low BP causing fainting.
MSK and dermatological impacts of pregnancy
increased lumbar lordosis ligamentous laxity (pelvic girdle pain) stretch marks skin pigmentation changes carpal tunnel sciatica cramps
