Lecture 3b: Pregnancy and Physiological Changes Flashcards
What are the main physiological changes during pregnancy?
- Hormonal
- Haematological (blood)
- Gastrointestinal
What happens to progesterone and oestrogen throughout pregnancy?
Rise continually throughout pregnancy - suppressing the menstrual cycle
What happens to HCG throughout pregnancy?
Huge sudden increase then plateau and decline after about 12-16 weeks then continue as low and stable levels
What do high circulating levels of oestrogen promote?
Prolactin production (pituitary gland enlargement)
What do higher levels of prolactin production mediate?
A change in the structure of the mammary gland from ductal to lobular-alveolar = milk hormone
What do high levels of parathyroid hormone promote?
enhance calcium uptake in the gut and reabsorption by the kidney - to support the second skeleton being development
What are the main increased hormonal changes during pregnancy?
- Progesterone
- Oestrogen
- HCG
- Prolactin
- Parathyroid Hormone
- Cortisol
- Aldosterone
What is HPL?
Human Placental Lactogen
Where is HPL produced?
In the placenta
What is the role of HPL?
- Decreases maternal insulin sensitivity and maternal glucose utilisation
- Increases gluconeogenesis
How does decreasing maternal insulin positively influence the fetus?
Raises maternal blood glucose levels, which helps to ensure adequate fetal nutrition
What is chronic hypoglycemia?
blood sugar levels remain consistently lower than normal over an extended period
What does chronic hypoglycemia lead to?
a rise in HPL, which induces lipolysis with the release of FFA’s - become available for mother as a fuel so more glucose can be utilised by the fetus
How does increasing gluconeogenesis positively influence the fetus?
To increase maternal glucose levels so more glucose is available for the fetus
How much does blood volume change during pregnancy?
Increases 40-45% - proportionally with cardiac output
What happens to blood volume in the first trimester?
Plasma volume increases early in pregnancy, faster than RBC volume = hematocrit falls
What happens to blood volume in the second trimester?
Increase in RBC is synchronised with the plasma volume increase = hematocrit stabilises
What is dilution anemia?
the concentration of red blood cells (RBCs) in the blood is reduced due to an increase in plasma volume proportionally - haemoglobin will be lower
If plasma volume increases, will haemoglobin be lower or higher?
Lower