Pregnancy Physiology Flashcards
What are the haemotological changes that happen in pregnancy?
- Increased blood volume
- Increased plasma volume
- Mild increase in WBC count
- Increased fibrinogen
- Increased clotting factors VIII, IX and X
- Decreased haematocrit
- Decreased haemoglobin concentration
- Decreased protein S
- Decreased anti thrombin
- Decreased platelet
What is microcytic anaemia characterised by?
Low haemoglobin and low mean blood cell volume –> indicates iron deficiency
What is macrocytic anaemia characterised by?
Low haemoglobin and high mean blood cell volume –> indicates vitamin b12 and folate deficiency
What are the respiratory changes that happen in pregnancy?
- increased metabolic rate
- increased oxygen consumption
- increased arterial pO2
- decreased arterial pCO2
What are the cardiac changes that happen in pregnancy?
- increased cardiac output
- increased stroke volume
- increased heart rate (by 10bpm)
- increased plasma volume
- decreased peripheral vascular resistance
What is the most common liver disease in pregnancy?
Obstetric cholestasis - raised bile acid, AST and ALT
Fetus may pass meconium in the amniotic fluid –> meconium aspiration
How should antithyroid drugs be used in pregnancy for the management of hyperthyroidism?
In the 1st trimester, put the patient on PTU
After the 1st trimester, switch to carbimazole to avoid its effects on organogenesis in the 1st trimester (can cause fetal abnormalities)
Then, switch to PTU for a short amount of time which is not likely to cause maternal liver failure.
What are the drugs used for diabetes that are contradicted in pregnancy?
- Statins
- ACE inhibitors
What are the renal changes that happen in pregnancy?
- 50% increase in renal blood flow and GFR
- decreased serum creatinine, urate and albumin
Which anticonvulsant is associated with the greatest risk of fetal abnormalities?
- Sodium valproate
What is the treatment of choice for VTE in pregnancy?
Low MW heparin
What are the anatomical changes that happen to the uterus during pregnancy?
- 10-20 fold increase in mass and blood flow
- change from pear shape to thin walled spherical structure
- smooth muscle hyperplasia and hypertrophy in 1st half of pregnancy and then stretching effect
- increased elastic + fibrous tissue
- appearance of uNK cells
- orientation of uterus straightens and dextrorotates
How and why is a mucous plug produced in the cervix?
Increased cervical glands results in increased mucous production.
Formation of mucous plug prevents any infection from ascending.
When is colostrum first produced?
16 weeks gestation
What may the trigger for the respiratory changes that happen in pregnancy be?
Progesterone
