Maternal changes during pregnancy Flashcards
What are the causative factors that are involved in pregnancy?
o High levels of steroids – oestrogen and progesterone
o Mechanical displacement
o Fetal requirements
What changes occur during pregnancy?
- increase in size of the uterus
- increased metabolic requirements of uterus
- structural and metabolic requirements of fetus
- removal of fetal waste products
- provision of amniotic fluid
- preparation for delivery and puerperium
What systems undergo changes during pregnancy?
- energy balance
- respiratory system
- cardiovascular system
- gastrointestinal system
- urinary system
- endocrine system
What hormones cause the most changes?
• placental peptides o hCG, hPL, GH – last two are produced by the placenta • maternal steroids o placenta takes over ovarian (CL) production around wk 7, after this the placenta takes over hormone production • placental and fetal steroids o progesterone, oestradiol, oestriol • Maternal and fetal pituitary hormones o GH, thyroid hormones, prolactin, CRF
What effect and systems do placental steroids have?
• Steroids: renin/angiotensin system respiratory centre GI tract blood vessels uterine myometrial contractility
What is the total weight gained from pregnancy?
- Fetus plus placenta - 5 kg
- Fat and protein - 4.5 kg
- Body Water (this is excluding that in other listed structures) – 1.5kg intravascular, interstitial. intracellular
- Breasts - 1kg
- Uterus - 0.5- 1kg
- Ideally keep to less than 13kg: failure to gain or sudden change needs monitoring
In pregnancy why does the energy output need to be increased?
o Need to increase energy output to cope with increased respiration and cardiac output
In pregnancy why does the storage need to be increased?
for fetus and for labour and puerperium
In pregnancy why does the fat and protein stores need to be increased?
o increased consumption and reduced use
o mainly laid down in anterior abdominal wall
o utilised later in pregnancy and puerperium
What is the metabolic rise?
- 350 kcal/day mid gestation 75% fetus and uterus
- 250 kcal/day late gestation 25% respiration(H&L)
- 9 calories=1g fat therefore 40g fat for 350kcal ie 1 large Mars Bar
What maternal changes of glucose occur in the first and second trimester?
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What changes does E2 and P cause on the angiotensin system?
What contributes towards water gain
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How does pregnancy impact the respiratory system?
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How does materal blood change
Maternal plasma volume increases by 50% and red cell mas by 20%, so Hb conc is decreased
Also, get increased efficiency of iron absorption to increase red cell mass
Increase in white cells and clotting factors..blood becomes hypercoagulable = increase in fibrinogen for placental separation, but increased risk of thrombosis
What changes occur in fetal blood?
How does smoking impact this?
- Fetal blood= increased Hband altered in type
- Increased O2 binding
- Oxygen given up by maternal Hb
• smoking increases maternal carboxy-Hb which is more permanent and reduces the increased binding = fetal hypoxia
What changes occur to the heart?
• expanding uterus pushes heart round changes ECG and heart sounds • increased cardiac output increased heart rate and stroke volume begins as early as 3 weeks to max 40% at 28 weeks for maternal muscle and fetal supply
Where is there increased blood flow to?
- uterus
- placenta
- muscle
- kidney and
- skin
How do steroids affect the GI tract?
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Why is folic acid used as a dietary supplement?
DNA production, growth and red blood cells for the uterus, placenta and fetus
What changes occur to the urinary system
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Describe the changes to the uterus
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Describe the changes to the cervix
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How do things return to normal?
- Dramatic and rapid fall in steroids on delivery of the placenta
- Most endocrine-driven changes return to normal rapidly
- Uterine muscle rapidly looses oedema but contracts slowly: never returns to pre-pregnancy size
- Removal of steroids permits action of raised prolactin on breast
