Hormonal changes& the maternal adaptation to pregnancy Flashcards Preview

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Flashcards in Hormonal changes& the maternal adaptation to pregnancy Deck (25)
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1

What is gestational diabetes?

-High blood sugar that develops during pregnancy& usually disappears after giving birth
-Too much insulin resistance
-Happens because they are already insulin resistant because they're pregnant( as hormones stimulate this change) because it increases the maternal glucose then facilitates transfer across the placenta

2

Describe what happens to the maternal RBCs in pregnancy

-Synthesis increases( stimulated by erythropoietin)
-Number increases but apparent anaemia due to dilution
-Haematocrit falls from approx 40% to 32%
-Approx 30% increase in intracellular 2-3 DPG facilitates offload of o2 release to fetus

3

What biochemical parameter in maternak blood has the most significant increase in % compared to non -pregnant women

-Triglycerides ( produces a lot during pregnancy)

4

Which B vitamins are needed for DNA synthesis

Folate( vitamin B9) and vitamin B12
-Lack of folate may cause neural tube defetcs

5

Where is progesterone produced during pregnancy?

-produced by the corpus luteum at the beginning of pregnancy
-Then the placenta takes over as the corpus luteum dies down

6

What is the role of estrogens in pregnancy?

-Stimulate synthesis of liver FAs & cholesterol
-cardiovascular adaptation to pregnancy
-Growth of uterus
-'priming' of uterus for labour
-weak anti-insulin activity( via enhanced cortisol)
-Onset of labour-relative rise v fall in progesterone
-Cervical ripening ( infiltration of leukocytes into the cervix; leads to collagen fibres breaking down, cervix ripens and this facilitates delivery)
-Stimulates renin-angiotensin-aldosterone axis
-When you want to deliver the baby, the uterus acts as a synctium; you get electrical connectivity& coordinated contraction- Estrogen is responsible for this

7

What is a significant difference in the renin-angiontensin-aldosterone axis

-Angiontensin II has little effect on the aldosterone axis
-The RAAS is predominantly a sodium losing system

8

What are Braxton-Hicks contractions?

-Spontaneous contractions over the uterus

9

What is the role of progesterone in pregnancy

-Prepares and maintains the endometrium to allow implantation
-produced initially by CL up to day 50-60 then placenta
-May have a role in suppressing the maternal immunologic response to fetal antigens thereby preventing maternal rejection of the trophoblast
-role in parturition
-Serves as a substrate for fetal adrenal gland production of glucocorticoids& mineralocorticoids
-Growth of mammary glands
-Maintenance of pregnancy( inhibition of uterine contraction& prevention of ripening of cervix)
-Induces overbreathing& lowering of maternal co2
-Stimulates the renin-angiotensin axis

10

What is Human chorionic gonadotrophin( hCG)

-the basis of the pregnancy test
-Rescue& maintenance of function of the CL( continued progesterone production)
-About the 8th day after ovulation or 1 day after implantation- hCG takes over for the corpus luteum
-Continued survival of the CL is totally dependant on hCG
-Survival of the pregnancy is dependent on CL progesterone until the 7th week of pregnancy
-Progesterone luteal synthesis begins to decline at about 6 weeks despite continued & increasing hCG production

11

What are the biological functions of hCG

-Stimulation of maternal thyroid activity
-hCG binds to the TSH receptors of thyroid cells
-LH-hCG receptor is expressed in the thyroid
-Possibly, hCG stimulates thyroid activity via the LH-hCG receptor and by the TSH receptor

12

What are the metabolic actions of hPL

-Maternal lipolysis and increase in maternal plasma free fatty acids (NEFAs)-providing a source of energy for maternal metabolism & fetal nutrition
-Anti-insulin or 'diabetogenic' action- increase in maternal insulin- favoring provision or mobilizable AAs and fetal protein synthesis as well as glucose for transport to the fetus
-Potent angiogenic hormone- may play an important role in the formation of fetal vasculature

13

List the different placental proteins

-human placental lactogen
-pregnancy- associated plasma protein-A( PAPP-A, part of the quadraple test)
-Vascular endothelial growth factor( VEGF)
-Placenta growth factor (PLGF)
-human chorionic gonadotrophin

14

What is the function of leptin in pregnancy& early development?

-Secreted by both cytotrophoblast cells& synctiotrophoblast; maternal levels are significantly higher than in non pregnant women& that in the fetal circulation
-stimulates placental AA/FA transport
-Fetal leptin levels: positive correlation with fetal birth weight
-Probably plays an important role in fetal development& growth
-Women respond by becoming leptin resistant, allows them to keep eating as normal, and this helps the baby grow

15

What is the quadraple test used for?

-screens for downsyndrome, Patau's, Edwards and neural tube defects e.g spina bifida
-Done in the second trimester (usually between 15-20 weeks)

16

Describe the normal cardiovascular adaptation to pregnancy

-HR increases
-CO(aortic) increases then levels off
-TPVR decreases

17

What causes peripheral resistance to fall in pregnancy

-Increased NO synthesis
-Increased prostacyclin synthesis
-Relaxin possibly
-Increased compliance of vessels due to structural changes

18

What causes the increase in CO in pregnancy?

-Oestrogen--->ALL-renin-aldosterone increases
-Progesterone----> aldosterone increases
-Vasodilatory PGs----> aldosterone increases
-'shunting' of blood to uterine circulation stimulates sympathetic activity---> increased renin
-Renal Na loss due to increased GFR leading to increased renin
-hcG ---> increased renin

19

Outline skin blood flow in pregnancy

-predominantly increases in hands& feet
-Leads to: increased skin temp;increased nail growth;increased % of hairs actually growing
-Disappearance of Raynaud's syndrome
-nose bleeds, nose stuffiness, snoring

20

What is Raynaud's syndrome?

- A medical condition in which a spasm of arteries cause episodes of reduced blood flow; typically the fingers& less commonly the toes. are involved

21

Outline renal function in pregnancy

-Plasma concentrations of renal function i.e urea and creatinine decrease
-Glycosuria
-Calcicuria
-Urinary frequency increases
-Urinary stasis due to dilatation of collecting system
-Decreased osmotic threshold for AVP

22

What other physiological/anatomical changes occur during pregnancy?

-Rib cages gets pushed up
-Maternal oxygen consumption increases

23

Outline pulmonary function in pregnancy

-Tidal volume increases
-Deep breathing stimulated by progesterone
-RR unchanged
-Expiratory reserve reduced
-pCO2 decreases, po2 increases, pH unchanged( HCO3 falls)
-Costal margin& diaphragm altered

24

Describe coagulation& fibrinolysis in pregnancy

-Changes occur to induce low grade increase in coagulability- this is advantageous at delivery
-increase in Factors VII, VIII & X
-increase in plasma fibrinogen leads to increased ESR
-decreased fibrinolytic activity

25

What changes occur to the GI tract in pregnancy

Reduced smooth muscle tone leads to:
-Decreased cardiac sphincter tone
-Decreased motility and mobility
associated with:
-biliary stasis
-Increased gastric reflux ( heart burn)
-Increased nutrient absorption
-Increased water reabsorption