Maternal Physiology + Pregnancy Flashcards
(44 cards)
Why does the body need to adapt?
Volume support
Nutrition
Waste clearance
Pregnancy maintenance
Childbirth
What drives adaptational changes?
Hormones
Human placental lactogen
Oestrogen
Progesterone
hCG
What is gestational diabetes?
A glucose intolerance that is first recognised in pregnancy + does not persist after delivery
How does gestational diabetes occur?
Resistance to insulin is not met with a compensatory rise in maternal insulin > maternal hyperglycaemia
Adaptations in the respiratory system in pregnancy
tidal volume increases > increases ventilation
What is the clinical consequence of adaptations to respiratory system in pregnancy?
Dyspnoea
(Women may complain of feeling SOB)
Adaptations of the cardiovascular system in pregnancy
- reduced systemic vascular resistance to increased cardiac output by 40%
- increased procoagulants
- decreased anticoagulants ^v (increases clotting)
- reduced fibrinolysis
How does pregnancy cause an increase in cardiac output?
- oestrogen + progesterone cause a drop in BP
- stimulates RAAS
- AngII causes release of aldosterone
- aldosterone stimulates reabsorption at kidneys
- increases plasma volume > increased stroke volume + heart rate > increased cardiac output
What are the clinical consequences of adaptations to CVS in pregnancy?
- peripheral oedema (due to increased RAAS)
- dilutional anaemia (due to increase in plasma volume)
- hyper coagulable state > increased risk of DVT + PE
What is the most common cause of anaemia in pregnancy?
Iron deficiency
What is dilutional anaemia in pregnancy?
Plasma volume increases > dilutes RBCs > anaemia
Complications of anaemia in pregnancy
- increased morbidity for mum + baby
- preterm delivery
- infant iron deficiency anaemia
- maternal fatigue
Adaptations of the renal system in pregnancy
GFR needs to increase to increased clearance
- systemic vasodilation > increased renal blood flow
- decreased PCT absorption
- smooth muscle relaxation > increased size of kidneys + ureters
What is normally seen in U&Es in pregnancy?
Decreased serum urea + creatinine
What effect does the changes in the renal system in pregnancy have?
- increased GFR
- decreased serum urea + creatinine
- glucosuria
- increased risk of UTI
Adaptations in the GI system in pregnancy
slow transit time to increase absorption
- progesterone causes smooth muscle relaxation in GI tract > slow gastric emptying
- nausea, constipation + heart burn
Adaptation of the thyroid in pregnancy
- oestrogen increased liver production of thyroid binding globulin
- causes increase in TSH + thyroxine production
- free levels are unchanged
How are the change in the endocrine system in pregnancy achieved?
Thyroid regulation
Parathyroid activation
Insulin resistance
Changes to calcium metabolism in pregnancy
Why is this needed?
- increased calcitriol
- increased calcium reabsorption in gut
- increased phosphate excretion in kidneys
. - allows for greater calcium availability for fetus > optimal bone growth
What changes to glucose metabolism occurs in pregnancy?
- reduction in maternal blood glucose + aa conc.
- insulin resistance in 2nd half of pregnancy
- increase in maternal free fatty acids, ketone + triglyceride levels (alternative metabolic fuel)
- increased insulin release in response to normal meal
Risk factors of gestational diabetes
- BMI >30kg/m2
- previous macrosomic baby
- previous gestational diabetes
- family history
- ethnicity with high prevalence of diabetes (Asian)
Impact of gestational diabetes on fetus
- Increased birth weight
- Congenital defects especially cardiac, renal, unreal tube defects
- Stillbirth
Investigations of gestational diabetes
Oral glucose tolerance test
Consequences of gestational diabetes to mother
- increased risk of pre-eclampsia, polyhydramnios + premature labour
- shoulder dystocia during labour
- increased risk of developing type 2 DM
