Metabolism in Pregnancy Flashcards
How do substances transfer from mother to foetus?
Through the placenta down the concentration gradient by simple diffusion.
In pregnancy, which body is in control?
The foetus has some control of maternal metabolism to ensure its own survival.
In pregnancy, what secretes hormones which control the maternal hypothalamic pituitary unit?
The fetoplacental unit. It secretes hormones which are hypothalamic like, pituitary like and also steroid hormones.
Name the pituitary like hormones secreted by the fetoplacental unit:
ACTH, human chorionic thyrotropin, human chorionic gonadotropin, human placental lactogen.
What are the fetoplacental steroid hormones?
Oestrial and progesterone.
What is the main process occuring in the first half of pregnancy?
Anabolic processes which are preparing the maternal systems to support the fetus. There is also a small increase in insulin sensitivity.
What 3 processes is the anabolic stage of pregnancy preparing for?
More rapid fetal growth, birth and subsequent lactation.
What changes occur to maternal metabolism in the 2nd half of pregnancy?
There is reduced maternal utilisation so that more is available to fetus, there is also delayed nutrient disposal following meals and release of the fatty acid stores built up at the beginning of pregnancy.
What happens to insulin/anti insulin ratio at the second half of pregnancy and what is the effect of this?
Overall the ratio falls, and this leads to a decrease in insulin sensitivity and so glucose and fatty acid concentration in the blood is kept high.
What is the anti-insulin hormone secreted from the fetoplacental unit, and what change to maternal metabolism does this cause?
Corticotropin releasing hormone, this impairs glucose uptake into muscles and adipose.
What is the potential problem caused by anti insulin hormones?
They can lead to hyperglycaemia following meals and hypoglycaemia at night or in between meals.
What is the normal effect that pregnancy has on insulin secretion?
Under normal circumstances, increased appetite leads to increased glucose. oestrogen and progesterones lead to increased sensitivity of pancreatic B cells and this leads to an increase in insulin secretion.
What is gestational diabetes?
This is diabetes which occurs because the pancreas is not able to produce enough extra insulin which is required during pregnancy.
What can cause gestational diabetes?
Autoantibodies like in T1DM, genetic susceptibility or B cell dysfunction and chronic insulin resistance (likely to evolve into T2DM)
What is the standard management plan for gestational diabetes?
Normally there is calorie reduction in obese patients, insulin injections for patients who suffer persistent hyperglycaemia, and scans to ensure fetal well being and growth.
