Maternal Adaptations Flashcards
What happens to the CVS during pregnancy?
Oxygen consumption increases
- foetal oxygen requirements
- increasing maternal metabolic rate
What happens to the plasma volume?
Increases
- increased afterload
What happens to the stroke volume?
Increases
What happens to the systemic vascular resistance?
Decreases due to vasodilation caused by progesterone
What happens to the heart rate?
Increases by 10-20 bpm
What happens to the cardiac output?
Increases
What times throughout pregnancy are women with pre-existing heart disease most at risk?
Labour
What are the ECG changes seen in pregnancy?
Atrial + ventricular ectopics
Left axis shift
ST depression + T wave inversion in inferior + lateral leads
What happens to urinary output?
Increases due to increased renal blood flow due to vasodilation by progesterone
What can occur in pregnancies to the renal system?
Ureter compression
UTIs
Urinary incontinence
Why does ureter compression occur?
Growth of the foetus
What is the effect of ureter compression?
Hydronephrosis - back flow of urine
Why do UTIs occur?
Stasis and increased pressure due to foetal position
Causes backflow to the kidneys
Why does urinary incontinence occur?
Pelvic floor muscles weakened
What can be found in the urine of pregnant women?
Glucose
Calcium
Protein
Bicarbonate
What happens to plasma osmolarity?
Decreased
What happens to progesterone levels?
Increased
What are the effects of progesterone?
Relaxes smooth muscle
Slows gastric emptying
Vasodialtion
What happens to oestrogen levels?
Increased
What are the effects of oestrogen?
Breast tissue growth
Water retention
Increased protein synthesis
What other hormone is produced?
Relaxin
What is the effect of relaxin?
Softens the cervix and pelvic ligaments in preparation for birth
What happens to prolactin levels?
Increased
What are the effect of prolactin?
Stimulate breast development
Promotes lactation
What can occur in pregnancy due to the GI system?
Acid reflux
Constipation
Why does acid reflux occur?
Relaxation of the lower oesophageal sphincter due to progesterone
Why does constipation occur?
Slowing of peristalsis due to progesterone
How does immunity change in pregnancy?
Shifts from T helper 1 (cell mediated immunity) to T helper 2 (humoral immunity)
What is the effect of hCG on maternal immunity?
Reduces levels of
- IgA
- IgG
- IgM
What happens to the respiratory system?
Increased oxygen demand - increases respiratory drive
What happens to the tidal volume?
Increases
What happens to respiratory rate?
Stable
What is the ABG pattern in pregnancy?
pH 7.4-7.45
pO2 increased
pCO2 decreased
Mild respiratory alkalosis
What are the early changes to the respiratory system?
Increase in subcostal angle
Increase transverse diameter
Increase circumference of chest
What are the later changes to the respiratory system?
Elevation of the diaphragm
What happens to glucose levels in pregnancy?
Increase in insulin resistance due to placental lactogen
Hyperplasia of pancreatic B cells - increase insulin levels
What is gestational diabetes?
Diabetes first diagnosed in pregnancy
How is gestational diabetes diagnosed?
Glucose tolerance test at 28 weeks
- fasting glucose > 5.6
- 75g sugar
- 2 hours
- glucose >7.8
What is the effect of gestational diabetes on foetus?
Foetal macrosomia = larger baby
Post delivery foetal hypoglycaemia - hyperinsulinaemia still present
What are the effects of gestational diabetes on the pregnancy?
Increased risk of stillbirth
Increased risk of requiring induction of labour
Polyhydraminos = excess amniotic fluid
Shoulder dystocia
What is pre-eclampsia?
Raised blood pressure and proteinuria in pregnancy
How is pre-eclampsia diagnosed?
> 140/90 on 2 separate occaisions >4 hours apart
Proteinuria
What causes pre-eclampsia?
Impaired trophoblast differentiation + invasion causing insufficient placental bloodflow
What are risk factors for pre-eclampsia?
>40 History of pre-eclampsia Pre-pregnancy obesity Diabetes Pre-existing hypertension Family history
What do you give patients with pre-eclampsia risk factors?
75mg aspirin OD
What are the symptoms of pre-eclampsia?
Headache Visual disturbance RUQ pain Seizures Hyperreflexia Oedema
What are the effects of the foetus with pre-eclampsia?
IUGR = intrauterine growth constriction
Still birth
How is pre-eclampsia managed?
Anti-hypertensives
If hyper reflexive - magnesium sulphate
Main treatment = delivery
Why do you get anaemia in pregnancy?
Plasma volume increases 50%
Red cell mass only increases 20%
How is anaemia in pregnancy managed?
Ferrous sulphate
