Maternal changes in pregnancy Flashcards
What are the causative factor which cause a major change in multiple systems?
- High levels of steroids
- Mechanical displacement
- Fetal requirements
What do we have to do in order to diagnose an abnormality during pregnancy?
In order to diagnose an abnormality in pregnancy, we need to detect changes in the changes
What could pregnancy do to maternal conditions?
- Exacerbate a pre existing condition
- Uncover a hidden or mild condition
What are the changes designed to cope with several main events?
- Increase in size of the uterus
- Increased metabolic requirements of the uterus
- Structural and metabolic requirements of fetus
- Removal of fetus waste products
- Provision of amniotic fluid
What are the hormones causing the most of the changes?
- Placental peptides
- hCG, hPL, GH
- Maternal steroids
- Placental and fetal steroids
- Progesterone,oestradiol, oestriol
- Maternal and fetal pituitary hormones
- GH, thyroid hormones, prolactin, CRF
What do placental steroids have an effect on?
- Renin angiotensin system
- Respiratory centre
- GI tract
- Blood vessels
- Uterine myometrial contractility
Weight during pregnancy
Weight gain happens during pregnancy
Why is there a need to increase energy output?
To cope with increased respiration and cardiac output
Why is there a need for increased storage?
- For fetus
- For labour and puerperium
How much fat and protein need to be gained and how?
Need to gain fat and protein stores by 4-5kg
-Increased consumption and reduced use
Where is the fat and protein store mainly laid in the pregnant mother?
Store mainly laid down in anterior abdominal wall
When is a increased availability for glucose required?
Increased availability needed in 2nd timester
How is the glucose transported to the fetus?
Transported across placenta as facilitated diffusion as fetal energy source
Where does the fetus store some of the glucose?
Fetus stores some glucose in the liver
What happens in the 1st trimester to the maternal glucose reserves?
- beta cells increase in number
- Plasma insulin increases
- Fasting serum glucose decreases
What happens in the 2nd trimester to fetal glucose reserves?
- hPL causes insulin resistance
- There’s less glucose in storage and therefore increased availability in serum glucose
- However this can cause diabetes
What do oestrogen and progesterone act on to increase water gain during pregnancy?
Act on renin angiotensin system causing an increase in plasma volume
How many litres do mothers gain during pregnancy and what contributes to this?
Gain about 8-9 litres Contributed by: -Fetus -Placenta -Amniotic fluid -Oedema -Uterine muscle -Mammary gland -Plasma volume
What happens to oxygen consumption during pregnancy ?
Oxygen consumption increased
How does oestrogen and progesterone cause an increase in respiration?
- Increases respiratory centre sensitivity to CO2
- Thoracic anatomy changes, ribcage is displaced upwards and ribs flare outwards
By what percentage does minute volume increase during pregnancy?
-Minute volume increases by 40%
What happens to arterial pO2 and pCO2 during pregnancy?
Arterial pO2 increases and arterial pCO2 decreases
Therefore what does high oxygen facilitate with?
High oxygen will facilitate gas transfer between the mother and the baby
What happens to maternal plasma volume during pregnancy?
Increase in maternal plasma volume
During pregnancy what is there an increased efficiency of in the maternal blood?
-Increased efficiency of Iron absorption from gut
What is haemodilution?
Is the apparent anaemia as concentration of Hb falls as plasma volume increases
What other changes happen in maternal blood during pregnancy?
Changes in white cells and clotting factors
Why does blood become more hypercoagulable?
Due to increased fibrinogen for placental separation
There’s an increased risk of thrombosis
What does increased Hb in fetal blood allow?
-Increased Hb allows increased O2 binding, therefore oxygen is given up by maternal Hb more easily
What does smoking result in to the fetal blood?
Smoking increases maternal carboxy-Hb which is more permanent and reduces increased binding of oxygen leading to fetal hypoxia
How does an expanding uterus effect the CVS?
- Pushes the heart round
- Changes ECG and heart sounds
Why is there an increased cardiac output during pregnancy?
- Due to increased heart rate and stroke volume
- For maternal muscle and fetal supply
What does an increased cardiac output and vasodilation by steroids result in?
Increased cardiac output and vasodilation by steroids result in reduced peripheral resistance
What occurs to the CVS to assist in heat loss?
Neoangiogenesis occurs including extra capillaries in skin to assist in heat loss
Effect of steroids on GI tract
steroids:
- Increase appetite and thirst
- Reduce GIT motility causing constipation
- Relax LOS causing acid reflux
Why do we need more folic acid during pregnancy?
Involved in DNA production, growth, blood cells for uterus placenta and fetus
What is a deficiency in folic acid linked to?
Linked to spina bifida
What does progesterone effect in the bladder?
Progesterone effects smooth muscle in bladder
What happens to the urinary tract during pregnancy and what does this increase?
Urinary tract dilates and relaxes however there’s increased UTI
During pregnancy there’s increased blood flow to kidneys, what does this therefore do and result in?
Increased blood flow to the kidneys cause an increased filtration rate. This results in an increased clearance of:
- Creatinine
- Urea
- Uric acid
In early pregnancy, why is there an increased frequency of urination?
In early pregnancy the uterus is enlarging but it is within the pelvis compressing the bladder increasing the frequency of urination
In mid-pregnancy, what leads to micturition being normal?
Mid-pregnancy the uterus is lifted out of the pelvis leafing to micturition being normal
At term, why is there an increased frequency of urination again?
At term the head of the fetus descends into the pelvis increasing frequency of urination again
Why is there a change in uterine size during pregnancy?
- Due to huge increase in muscle mass
- Huge increase in blood flow
What is the primary function of the cervix?
Primary function is to retain pregnancy
What happens to the vascularity of the cervix during pregnancy?
There’s an increase in vascularity
When do the tissues in the cervix start softening and how?
Tissues soften from 8 weeks
- Changes in connective tissue
- Begins gradual preparation for expansion
What happens to the glands in the cervix during a pregnancy and how?
Proliferation of glands:
- Mucosal layer becomes half of mass
- Great increase in mucus productions
After delivery of the baby what returns to normal in the mother?
- Dramatic and rapid fall in steroids on delivery of the placenta
- Most endocrine-driven changes return to normal rapidly
- Uterine muscle rapidly lose oedema but contracts slowly
- Removal of steroids permits action of raised prolactin on breast
