Session 8: Maternal Physiological Adaptations in Pregnancy Flashcards
Give examples of broad physiological adaptations caused by pregnancy.
Metabolism
Glucose
Respiration
Kidneys
Cardiovascular
Haematological
GI
Endocrine
What is the general driving force of the physiological maternal changes?
Hormones such as:
hCG
Oestrogen
Progesterone
hPL
Relaxin
Why is fat laid down in first half of pregnancy?
To help meet the demands of the fetus later in the pregnancy.
Explain the changes to fat, glucose and amino acids in pregnancy.
Blood glucose and amino acid conc. reduces.
Increased in maternal free fatty acids, ketone and triglyceride levels as an alternative metabolic fuel.
Explain the insulin effect in pregnancy.
There is an increased insulin resistance in the second half of pregnancy as well as increased insulin release in response to a normal meal.
This is to allow increased glucose availability for the foetus.
Function of hPL.
Generates maternal resistance to insulin.
Give an example of a hormone that has a similar role to hPL.
Prolactin
Function of oestrogen in materan adaptation.
Increase prolactin release
Function of progesterone in maternal metabolism adaptations.
Increase appetite in first half of pregnancy and diverts glucose into fat synthesis.
What is gestational diabetes?
Defined as glucose intolerance that is first recognised in pregnancy but does not persist after delivery.
How to diagnose gestational diabetes.
Oral glucose tolerance test (OGTT) where resistance to insulin is not met with a compensatory rise in maternal insulin.
This leads to maternal hyperglycaemia.
Complications of gestational diabetes.
Increased birth weight, congenital defects, stillbirth.
What are the mother’s energy needs met by in later pregnancy?
Metabolising peripheral fatty acids.
As the fetal-placental unit’s increasing need for nutrition progresses, how is this emt by cardiovascular changes?
Maternal vascular-neogenesis
How else is the increasing need for nutrition of the foetus solved?
Increased blood flow by changes in function of the maternal baro and volume receptors.
Where else is there increased blood flow in the mother?
To the growing breasts, kidneys and GI tract.
How does plasma volume change in pregnancy?
Increased about 50%
How does red cell mass change in pregnancy?
Increase about 20%
How does CO change in pregnancy?
Cardiac output increases from about 4.5 to 6 litre/min.
How is the increase in CO achieved?
Mainly by increased stroke volume