Physiology in pregnancy Flashcards
Why are pregnant people more prone to back pain?
In order to counteract the weight of enlarging fetus and increased blood volume they must lean backward, changing the curve of the spine
Why may ligamentous joints become less stable during pregnancy?
Relaxin increases oestrogen and progesterone which leads to increase pliability and extensibility of connective tissue
Does the basal metabolic rate increase or decrease during pregnancy?
Increase
What is a possible cause of gestational diabetes?
Human placental lactogen acts against maternal insulin
Why is heartburn and reflux common in pregnancy?
Delayed gastric emptying
Hormones relax LOS
Pressure from uterus
What is a knock-on effect of increased blood volume?
Oedema as a result of decreased venous return from compressed IVC
Physiological sodium and water retention and decreased secretion also contributes
How does levels of active thyroxine and iodothyronine stay the same when total level increases ?
The liver produces more thyroid binding globulin (TBG)
Why do maternal iodine requirements increase during pregnancy?
Iodine is actively transported to the fetoplacental unit
Urinary iodine secretion is doubled (increased GFR)
Why does the thyroid gland sometimes hypertrophy during pregnancy?
It is working harder to increase iodine uptake
How can Grave’s disease affect pregnancy?
TSH receptor antibodies can cross the placenta and cause fetal and/or neonatal hyperthyroidism
What is the leading indirect cause of maternal death in the UK?
Cardiac disease
How much does circulating blood volume increase by during pregnancy?
50-70%
Give some examples of conditions which could be affected by the increased blood volume.
Mitral stenosis
Pulmonary hypertension
DCM
What is the equation for systemic vascular resistance (SVR)?
(MAP-MVP) / CO
Does SVR increase or decrease during pregnancy?
Decreases
Increased circulating vasodilators and blood diverted to low pressure uteroplacental unit
