Flashcards in 8.2 Deck (16)
Describe the CVS changes in pregnancy?
CO 40% increase
SV 35% increase
Heart rate 15% increase
Blood volume Increase
Systemic vascular resistance 25/30% decrease
Blood pressure decreases
How does BP change in pregnancy?
• Systolic BP is never increased in Pregnancy (normally)
• Hypotension in Pregnancy
o T1 and T2 – Progesterone effects on Systemic Vascular Resistance (SMV)
o T3 – Aortocaval compression by gravid uterus. Reduced return to the heart.
How is endothelium involved in pregnancy?
o Controls vascular permeability
o Contributes to the control of vascular tone
• Vasodilation of pregnancy
How does GFR change in pregnancy?
Increases by 55%
What increases in renal system of pregnancy?
What decreases in renal system of pregnancy?
Why does urinary stasis occur in pregnancy? What can this result in?
• Progesterone relaxes the smooth muscle in the walls of the ureters, which can result in stasis, hydroureter, UTIs and pyelonephritis.
• Pyelonephritis can induce pre-term labour.
How does the respiratory system change in pregnancy?
• Diaphragm is displaced
• A-P and transverse diameters of thorax increase
How does oxygen consumption, FRC, VC, TV, Alveolar ventilation rate change?
How does the mother deal with the extra CO2 from the fetus?
During pregnancy there is a physiological hyperventilation driven by progesterone, so the mother can blow off the extra CO2 the fetus produces.
• Increased metabolic CO2 production
• Increased respiratory drive effect of progesterone
o Physiological dyspnoea
• Resulting in respiratory alkalosis, compensated by increased renal bicarbonate secretion (less reabsorption)
How does carbohydrate metabolism change in the first half of pregnancy?
Progesterone stimulates appetits - diverts glucose into fat synthesis.
Oesterogen stimulates an increase in prolactin release - generates a maternal resistance to insulin.
Maternal glucose use declines and gluconeogenesis
- maximises glucose for fetus.
How is the maternal insulin resistance achieved?
Human placental lactogen
How does blood glucose change in pregnancy?
• Decrease in fasting blood glucose
• Increase in post-meal (post-prandial) blood glucose
What is gestational diabetes?
Pancreas is unable to respond to metabolic demand of pregnancy with beta cell hyperplasia and hypertrophy and increased rate of insulin synthesis.
Loss of metabolic control and blood glucose increases.
Disappears after birth
Risk factors for gestational diabetes
Family or personal health history