Hormonal changes& the maternal adaptation to pregnancy Flashcards Preview

Human development block > Hormonal changes& the maternal adaptation to pregnancy > Flashcards

Flashcards in Hormonal changes& the maternal adaptation to pregnancy Deck (25)
Loading flashcards...

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


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


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

-Triglycerides ( produces a lot during pregnancy)


Which B vitamins are needed for DNA synthesis

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


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


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


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


What are Braxton-Hicks contractions?

-Spontaneous contractions over the uterus


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


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


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


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


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


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


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)


Describe the normal cardiovascular adaptation to pregnancy

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


What causes peripheral resistance to fall in pregnancy

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


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


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


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


Outline renal function in pregnancy

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


What other physiological/anatomical changes occur during pregnancy?

-Rib cages gets pushed up
-Maternal oxygen consumption increases


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


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


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