Week 8.1 - Maternal problems in Pregnancy Flashcards
Describe the cardiovascular changes which occur in pregnancy
-Blood Volume increases (upto 50%) therefore CO, SV and HR all increase
What happens to BP during pregnancy?
-Decreases in T1/T2 normal in T3 (systolic never increases)
What effects will pregnancy have on preload and afterload and why?
- Preload will increase as CO is increased, increased vol of blood returning to heart
- Afterload should decrease if BP decreases as TPR will decrease
Why is hypotension experiences in T1 and T2?
-Progesterone causes relaxation of smooth muscle in BVs therefore decreasin TPR
What could be a potentially dangerous cause of hypotension in T3?
-Aortocaval compression by enlarged uterus reducing venous return to the heart
Name one possible outcome of the bvs not vasodilating during pregnancy
-Pre-eclapsia -> uncontrolled hypertension with endothelial dysfunction
What changes occur in the urinary system during pregnancy?
-Glomerular filtration rate increases thus renal plasma flow increases and functional renal reserve decreases
What causes the increase in GFR during pregnancy?
-Progesterone
What happens to creatinine clearance during pregnancy? Why?
- Increases
- Because GFR has increased
What happens to urea excretion during pregnancy? Why?
- Increases
- Because GFR increases
\Why is it important to know the normal for pregnancy range of creatinine and urea?
-May look like they are in the normal range when they are in fact high for pregnancy as more urea and creatinine should be excreted, therefore there may be a problem with the kidneys
What is the range of creatinine clearance during pregnancy?
-40-50%
What is the approximate value of urea during pregnancy?
-~3.1mmol/L
Why is it significant that bicarbonate decreases during pregnancy?
-Reduced buffering capacity of the kidney
What is a potential problem which progesterone can place on the urinary system?
-Increasing GFR so much that hydroureter develops
Name a common cause of urianry stasis during pregnancy?
-Obstruction of ureter by gravid uterus
Why are UTIs concering during pregnancy?
-Possible to develop to pyelonephritis and cause pre-term labour
Name the anatomical changes which occur within the respiratory system during pregnancy
- Diaphragm displaced
- AP and transverse diameters of the thorax increase
Name the physiological changes which occur in the respiratory system during pregnancy
-Physiological hyperventilation due to increased CO2 production and increased respiratory drive effect of progesterone
How is physiological hyperventilation of pregnancy compensated for?
-Increased bicarb excretion to compensate for the respiratory alkalosis
What are the changes in the capacities of the lungs during pregnancy?
- Reduced functional residual capacity but total lung capacity remains unchanged
- Increased TV with RR unchanged
What happens to O2 consumption during pregnancy?
-Increases by 20%
Why is vital capacity unchanged during pregnancy?
-VC = TV+IRV+ERV
although TV increases ERV volume decreases so VC remains unchanged
What happens to carboydrate metabolism during pregnancy?
- Increased peripheral resistance to insulin by hPL and the body switched to gluconeogenesis and alternative fuels to spare glucose for fetus
- Decreased fasting blood glucose
- Increased post-prandial blood glucose
List some risk factors for gestational diabetes
- PCOS
- advancing age
- Ethnicity
What is gestational diabetes?
-Increased blood glucose during T3 due to improper insulin response which doesnt persist post partrum
What is the outcome on the fetus of poor control of gestational diabeted?
-Macrosomic fetus, still birth, congenital defects
What happens to lipid metabolism during pregnancy?
- Increased lipolysis for T2
- Increased plasma free fatty acids on fasting to spare glucose for fetus
Why is pregnancy associated with a risk of ketoacidosis?
-If there is inappropriate lipolysis excess FA can get converted to ketones
What happens to thyroid metabolism in pregnancy?
- Thyroid binding globulin, T3 and T4 increase so free T4 in normal range
- Decreased TSH due to the effects of hCG
Describe the anatomical changes to the GI tract during pregnancy
-Alterations in the disposition of the viscera eg appendix moves to RUQ as uterus enlarges
Describe the physiological changes which occur in the GI tract during pregnancy
- Smooth muscle relaxation by progesterone -> delayed emptying -> constipation
- Biliary tract stasis
- Increased risk of pancreatitis
Describe the haematological changes which occur during pregnancy
- Prothrombotic state with increased fibrin deposition at implatation site and increased fibrinogen and clotting factors in blood.
- Reduced fibrinolysis and changes in vascular flow due to venodilation
- Anaemia
Why cant you give warfarin in thromboembolic disease of pregnancy?
-Warfarin can cross the placenta and is teratogenic
What causes anaemia during pregnancy?
- Plasma volume increases more than red cell mass -> physiological anaemia
- Can also be due to Fe or folate deficiencies
Describe changes in the immune system during pregnancy
-Non-specific suppression of the local immune responses at the materno-fetal interface
Give 2 diseases which can occur due to transfer of antibodies across the placenta
- Haemolytic disease of the newborn
- Graves disease
