Maternal Changes In Pregnancy Flashcards
What are the changes in pregnancy that are designed to cope with the main event?
Increase in uterus size Increased uterine metabolic requirements Structural and metabolic requirements of the foetus Removal of foetal waste products Provision of amniotic fluid Preparation for delivery and puerperium
What systems do the placental steroids effect?
RAAS, resp system, GIT blood vessels and uterine myometrium contractility
What is the total amount of weight gain in pregnancy?
12-13 Kg
How much does the foetus and placenta weigh?
5Kg
How much do fats and protein increase in weight by?
4.5Kg
How much does the body water increase by?
1.5Kg
How much do the breasts increase in weight by?
1 kg
How much does the uterus increase in weight by?
0.5-1kg
Why do you need to increase energy in pregnancy?
To cope with increased respiration and cardiac output, labour, post labour and storage in the foetus
Where are the increased fat and protein stores found?
Interior abdominal wall
How much does the basal metabolic rate increase by in pregnancy?
250-350 kcal/day
How does the fetus get energy?
Activate transport through the placenta
What happens to glucose metabolism in the first trimester?
Pancreatic beta cells increase in number
Plasma insulin increases
Fasting serum glucose decreases
What happens to glucose metabolism in the second trimester?
hPL causes insulin resistance so there’s less stored glucose and more serum glucose
How does the body retain water in pregnancy?
E2 and progesterone act on the RAAS to retain sodium
How much water is retained in a pregnant human?
8,5L
Where does all the excess fluid get stored?
Ankles, lungs, connective tissue and ligaments
Ankles, lungs, connective tissue and ligaments
Increases respiratory sensitivity to CO2, changes in thoracic anatomy and deeper breathing
How does gas exchange change in pregnancy?
Arterial pO2 increases 10% and pCO2 decreases 15-20% to facilitate gas transfer between the foetus and mother
By how much does the plasma volume increase in pregnancy?
40-50%
By how much does the red cell mass increase in pregnancy?
18-20%
What is haeomodilution?
Apparent anaemia that happen when the concentration of Hb falls
What happens in the gut to allow for increased red cell mass?
Increased iron absorption efficiency
Why is there an increase in white cells and clotting factors in pregnancy?
Increased fibrinogen for placental separation but an increased risk of thrombosis
What happens to the heart in pregnancy?
Increased heart rate and stroke volume (ie increased cardiac output)
What results from the heart being pushed around because of the expanding uterus?
Changing ECG and heart sounds
Where does blood flow increase to in pregnancy?
Uterus, placenta, muscle, kidneys and skin
What causes the reduced peripheral resistance in pregnancy?
Increased cardiac output and vasodilation by steroids
Why does blood flow to the skin happen in pregnancy?
To assist in heat loss
How does progesterone affect the GIT?
Reduces gut motility, relaxes the lower oesophageal sphincter and affects appetite and thirst
When is it advised to take folic acid supplements?
3 months before conception up to week 12
What can folic acid deficiency be linked to?
Spina bifida
Why are pregnant people at an increased risk of a UTI?
Progesterone is a smooth muscle relaxant, so dilates the kidneys and ureters
How much does blood flow to the kidneys increase in pregnancy?
40-50%
Why doesn’t the second trimester cause increased urinary frequency?
Uterus is lifted out of the pelvis
By term, what proportion of blood flow is in the placenta/ uterus at any given time?
1/6
Why is the lower uterine segment less muscular and more fibrous than the rest of the uterus?
Act like a tunnel in labour
What is the cervix’s primary function in pregnancy?
Stay closed and retain the pregnancy
Why does the cervical tissue soften from 8 weeks?
Gradual preparation for expansion
Why is there a big increase in mucus production from the cervix in pregnancy?
Protective
