Physiological Changes in Pregnancy Flashcards
What types of changes occur during pregnancy
Renal changes
CVS changes
Endocrine changes
Immunity changes
GI tract changes
Calcium changes
Musculoskeletal changes
Respiratory changes
Glucose changes
What endocrine changes occur in the mother during pregnancy
Oestrogen and progesterone cause non-contractile nature of uterus and foster development of endometrium for pregnancy
Inhibin - prevents futher pregnancies
Progesterone - relaxes smooth muscle, dilates vessels, slows gastric emptying and slows peristalsis
Oestrogen - breast tissue growth, water retention, protein synthesis
Relaxin - softens cervix and pelvic ligaments for birth
TSH - decrease due to hCG which can stimulate TSH receptors
Prolactin - breast development. Promotes and maintains lactation postpartum
Oxytocin - prepares breast for lactation. Important in let down process of breast feeding. Stimulates uterine contractions and dilates cervix before birth
What are the CVS changes in the mother during pregnancy
Increased plasma volume
Increased stroke volume
Decreased systemic vascular resistance
Increased heart rate
Increased cardiac output
BP changes - Decrease from 9-21st wk -> rises from 21st wk to term
What clinical CVS signs can occur during pregnancy
Displacement of apex beat due to hypertrophy
May have split S1 murmur
May have ECG changes:
- Atrial and/or ventricular ectopics
- Left shift in QRS axis
- Small Q wave and inverted T wave in lead III
- ST segment depression and T wave inversion in inferior and lateral leads
What renal changes occur in the mother during pregnancy
Increased renal blood flow resulting in increased GFR causing:
- Glycosuria
- Bicarbonaturia
- Calciuria
- Proteinuria
- Decreased plasma osmolarity
Kidney is stimulated to:
- Increase renin production
- Increase EPO production
- Increase active Vit D production
Why might pregnant mothers experience urinary incontinence
Progesterone causes hypomobility of ureters resulting in urine stasis -> increased risk of urine/bladder infection and urinary incontinence
Gravid uterus can compress on ureters -> urinary incontinence
What calcium changes occur in the mother during pregnancy
There is increased intestinal Ca absorption to meet Ca requirements of pregnancy
Driven by increased calcitriol
What GI tract changes occur in the mother during pregnancy
Relaxation of lower oesophageal sphincter -> acid reflux and heartburn
Decreased peristalsis -> constipation, bloating and haemorrhoids
Increased risk of gallstone
Changes in taste - pica
Morning sickness
What immunological changes occur in the mother during pregnancy
There is recued cell-mediated immunity and T helper 1 cytokine production to prevent foetal rejection
This is balanced by increased humoral immunity
hCG decreases maternal levels of IgA, IgG and IgM
Results in immunosuppression
What respiratory changes occur in the mother during pregnancy
Increased O2 consumption due to increased metabolic rate
Progesterone stimulates respiration and respiratory drive
Increased resting minute ventilation due ot increased tidal volume
Increased minute ventilation causes increased pO2 and decreased pCO2 -> mild respiratory alkalosis
Decreased FRC in 3rd trimester due to decreased residual volume and expiratory reserve volume
Harder to breath comfortably due to uterus pressing on diaphragm
What musculoskeletal changes occur in pregnancy
Pain in the abdominal region - must distinguish from other causes of abdo pain
Pain in ribs and coccyx due to relaxed joints
Waddling gait
Increased lumbosacral curve
What glucose changes occur in the mother during pregnancy
Insulin resistance increases mid-pregnancy, increasing in 3rd trimester - due to hPL
There is hyperplasia of beta-cells resulting in increased insulin to counter the increased resistance
Increased insulin resistance increases glucose in the blood -> increases glucose available for the foetus
What is gestational diabetes
Where a woman has diabetes during pregnancy
Risk increases with obesity and increased maternal age
Strict glycaemic control improves maternal and foetal outcomes
What is GDMs effect on pregnancy
Foetus becomes hyperglycaemic
Foetal macrosomia due to increased insulin release in response to maternal hyperglycaemia
Can have congenital malformations
Jaundice
Increased risk of: stillbirth, IOL and CS
Perineal trauma and postpartum haemorrhage
Polyhydramnios
Shoulder dystocia
Post delivery foetal hypoglycaemia
Why might a mother develop anaemia during pregnancy
Due to increased plasma volume and increased cell mass but no increase in Hb -> decreased haematocrit - Hb production and RBC production are not dependent on each other
Mother requires more iron to produce more Hb
What are the consequences of poor foetal-placental perfusion
Decresed growth of baby/growth restriction
Still-birth
Why might a pregnant mother have lower limb oedema, varicose veins and/or haemorrhoids
Due to venous distension and engorgement
Venous distension - due to dilated vessels
Engorgement - due to compression of IVC
What is pre-eclampsia
Raised BP and proteinuria
Arises de novo after 20th wk gestation in previously normotensive woman
What causes pre-eclampsia
Pre-eclampsia is caused by imparied trophoblast differentiation and invasion during 1st trimester resulting in failure of trophoblast cells to destroy muscularis layer of spiral arterioles -> hypoxia and ischaemic placenta
Placental unit does not have normal blood flow -> cause maternal hypertension
What are the risk factors for pre-eclampsia and what is given to women who have these risk factors
Aspirin is given to patients with the risk factors:
>40yrs
Previous/family history of pre-eclampsia
Pre-pregnancy obesity
Women who became pregnant via donor eggs, embryo donation or donor inseminatoin
Diabetes
Pre-existing hypertension
Women with conditions such as anti-phospholipid syndrome
Women with renal disease
What does pre-eclampsia cause in the body
Widespread systemic inflammation - affects multiple organs
Proteinuria -> decreased plasma osmolarity and oedema
Increased peripheral resistance -> vasospasm and hypertension
Vasoconstriction in hepatic bed leads to periportal fibrin deposition, haemorrhage and hepatocellular necrosis
Enhanced vascular sensitivity to angiotensin II and NA -> vasoconstriction and hypertension
What are the signs and symptoms of pre-eclampsia
Headache
Visual disturbances
Right upper quadrant pain
Seizures
Hyperreflexia
Oedema
Worsening kidney and liver functions
What foetal concerns are assocaited with pre-eclampsia
Intra-uterine growth restriction
Stillbirth
Iatrogenic preterm birth
What does pre-eclampsia lead to and how is it treated
Pre-eclampsia leads to eclampsia which causes seizures
Must be treated with magnesium sulphate and follow through with birth
How is pre-eclampsia treated
Antihypertensives
Give magnesium sulphate if hyperreflexive
IOL or CS/delivery (main treatment)
