Flashcards in Repro 8.2 Maternal problems in pregnancy Deck (44)
What systems undergo changes during pregnancy?
What changes occur to the CVS during pregnancy?
-Blood volume increases by up to 50%
-Cardiac output, stroke volume and heart rate all increase
-Blood pressure falls
-vascular resistance decreases
Why do changes happen to the CVS system during pregnancy?
-to prepare for partuition
-to provide for the foetus and placenta.
What happens to the blood pressure over the course of a pregnancy?
T1 and T2- decreased
Systolic blood pressure should not change throughout/
What causes the increase in blood volume during pregnancy?
Oestrogen and progesterone affect the RAAS system, and reduce water and sodium excretion, therefore blood volume increases.
What effects do progesterone and oestrogen have on the CVS during pregnancy?
-increase blood volume (by alterring RAAS and causing retention of sodium and water)
-decrease peripheral resistance by causing systemic vasodilation
What should be considered when measuring a pregnant woman's blood pressure?
You should not measure her BP whilst lying supine becuase the gravid uterus can compress the IVC, reducing blood return to the heart, so the patient will become hypotensive.
What is the condition known as when a pregnant woman's blood pressure is taken lying down?
Supine hypotensive syndrome.
What effects does pregnancy have on the urinary system?
-Increased creatinine, protein clearance
-relaxation of the collecting systems.
Why does GFR increase during pregnancy?
progesterone leads to vasodilation of the afferent arteriole, increasing the amount of blood going to the kidneys and being filtered.
What happens to blood levels of urea, creatinine and bicarbonate ions during pregnancy?
They all decrease.
Urea and creatinine due to increased clearance.
Bicarbonate due to compensation of physiological respiratory alkalosis by increasing excretion of HCO3-
Why might you detect glucose in the urine of a pregnant woman?
there is an increased GFR and renal blood flow, but there is a fixed reabsoprtive capacity of the PCT, so only a certain amount of glucose can be reabsorbed.
If this limit gets exceeded, the remaining glucose will be excreted into the urine.
Why are pregnant women more prone to UTI's?
How is this avoided?
-relaxation of the ureters causes stasis of urine, which is an ideal breeding ground for bacteria.
-immune system becomes compromised in the pregnant state.
-Each time a pregnant woman goes for a check up she will have a urine dip stick to test for any UTI's so they can get treated early.
What urinary pathology are pregnant females more likely to encounter?
-Hydronephrosis (due to relaxation of the ureters, and the slow movement of urine)
-AKI (secondary to pyelonephritis)
What anatomical changes happen to the respiratory system during pregnancy?
-Displacement of the diaphragm due to the presence of the gravid uterus
-increased AP and transverse diameter of the thoracic cavity
What physiological changes happen to the respiratory system during pregnancy?
-increased tidal volume
-increased alveolar ventilation
-increased minute ventilatory volume
-decreased functional residual capacity
What is 'physiological hyperventilation' in pregnancy?
What can this cause?
progesterone causes an increased respiratory drive which causes dyspnoea.
This can lead to hyperventilation where too much CO2 is being blown off.
As a result respiratory alkalaemia can develop.
This is compensated for by the kidneys which excrete bicarbonate ions.
What is the risk of the kidneys compensating for respiratory alkalosis during pregnancy?
The icnreased excretion of HCO3- ions means there is a reduced HCO3- buffer, so acidosis is more likely to occur during pregnancy.
What metabolic changes occur to the mother during the first half of pregnancy?
-increase insulin:anti insulin levels
-building up stores for the fetus later in the pregnancy
What metabolic changes occur in the mother in the last half of pregnancy?
-decreased insulin:anti insulin levels
-increased blood glucose levels available for the fetus
What's the benefit of increased peripheral insulin resistance during pregnancy?
How does the mother deal with this?
It means less glucose is taken up into the cells, so plasma glucose levels increase, leaving more for the fetus to use.
The mother switches to fatty acids and gluconeogenesis for her fuel.
During pregnancy, what happens to blood levels of ketones, free fatty acids, cholesterol and glucose levels in the mother?
-ketones, free fatty acids and cholesterol all increase (the mother i know using this for her fuel)
-Glucose transiently increases following a meal (due to increased insulin resistance) But otherwise it has decreased levels because the fetus is using lots of glucose.
Which hormone promotes the metabolic changes that happen during pregnancy?
Human placental lactogen.
(oestrogen, progesterone and cortisol also help)
What are the effects of Human placental lactogen during pregnancy on metabolism?
-helps inhibit glucose uptake
-increases insulin release
-increases free fatty acid levels
Why is ketoacidosis associated with pregnancy?
Due to low insulin:anti insulin ratio and increase free fatty acid levels in the blood.
Also reduced bicarbonate buffering ability increases risk of acidosis
What is gestational diabetes?
A state of carbohydrat3e intolerance which occur in pregnancy and disappears after pregnancy.
What risks are associated with gestational diabetes?
What happens to thryoid levels in pregnancy?
TBG and T3/4 levels are increased.
Free levels of T3 and T4 are the same (due to the increased TBG being able to bind more)
TSH can be decreased (negative feedback)
What stimulated changes to the thyroid gland in pregnancy?
Human chorionic gonadotrophin directly acts on the thyroid gland, increasing T3/4 production.