8.2 Maternal Problems in Pregnancy Flashcards
Why does blood volume increase in pregnancy?
Compensate for blood loss in pregnancy
In the CVS, which things increase in function?
Cardiac output
Stroke volume
Heart rate
Pre-load
In the CVS, which things decrease in function?
Systemic vascular resistance
After-load
Describe the changes in blood pressure throughout a pregnancy
Trimester 1 and 2- decreases
Trimester 3- goes back to normal
Why is systemic peripheral resistance reduced in T1 and 2?
Progesterone causes vasodilation
Why does blood pressure return to normal (increase from hypotension) in trimester 3?
Pressure on aorta and IVC from uterus
What happens in pre-eclampsia with regard to the endothelium of the vessel walls and the plasma?
Plasma is contracted
Endothelium is contracted
In pregnancy what happens to GFR?
Increases
Why does the functional renal reserve decrease in pregnancy?
Progesterone dilates the efferent and afferent arterioles meaning it is hard to increase the GFR through vasodilation. Less capacity to compensate for a drop in GFR
What happens to the levels of urea and creatinine in pregnancy?
Decrease
What is a hydroureter?
Dilation of the ureter or obstruction causes urinary stasis
What happens to the vital capacity in pregnancy?
Does not change
What happens to the tidal volume in pregnancy?
Increases
What happens to the functional residual volume in pregnancy?
Decreases
Why does physiological hyperventilation occur in pregnancy?
Breathe more O2 to remove excess CO2 from the fetus.
How is physiological hyperventilation compensated for by the body in pregnancy?
Increased renal bicarbomnate excretion.
Body will struggle to cope with compensating for metabolic acidosis
Why does physiological dyspnoea occur in pregnancy?
Progesterone-driven hyperventilation means the patient can feel themselves breathing more deeply
What happens to maternal insulin resistance levels in pregnancy?
Increase so the mother switches to gluconeogenesis. Glucose is passed through the placenta to the fetus
What hormone increases the mother’s resistance to insulin?
hPL (human placental lactogen)
What is gestational diabetes?
Insulin resistance increases too much so mother develops hyperglycaemia
What affect on the fetus does gestational diabetes have?
Macrosomia (large fetus)
Describe the changes in fat metabolism throughout pregnancy
T1- increase in fat stores
T2- increase in lipolysis and plasma free fatty acids
Why are fat stores important for the mother in late pregnancy?
Mother uses fat stores as energy supply. Fat cannot cross the placenta so fetus does not take away energy
What is the mother at risk of in T2 when using fatty acids as an energy source?
Ketoacidosis
What happens to levels of T3 and T4 in pregnancy?
Increased
Free T4 remains the same due to equal increase in thyroid binding globulin
What GI complications can arise in pregnancy?
Complications due to stasis:
Gall stones
Constipation
Pancreatitis
How does the composition of the mother’s blood change in pregnancy?
Increased fibrinogen
Increased clotting factors
Reduced fibrinolysis
What is thromboembolic disease?
Excess clotting factors cause inappropriate clots in vessels
Why can warfarin not be used to thin the blood in pregnancy?
Teratogen in pregnancy
Why can physiological anaemia occur in pregnancy?
Plasma volume increases and RBC mass increases but not as much resulting in a dilation of RBCs in plasma.
May also develop an iron or folate deficiency
How is the maternal body adapted to not reject the fetus?
Local immune system at materno-fetal interface is reduced
What is thyroiditis?
Antibodies against the thyroid can be transferred to the fetus
