Flashcards in Pregnancy Deck (24)
What are the features and risks of the first trimester?
If you pass this, then 90% reach term
What are features and risks of second trimester?
What is the point of viability?
Modern technology - 22 weeks
50% chance of survival at 25 weeks
What are the features and risks of third trimester?
up to 39/40 weeks
What are the maternal changes associated with pregnancy?
Increased weight - more so in 2nd and 3rd
Increased/altered hormones - HCG (peaks in first trimester) , increased oestrogen and progesteron, HPL
Increased blood clotting
Decreased blood pressure
Increased basal body temp
Increased breast size
Increased vaginal mucus secretion (clear)
Increased nausea and vomiting
Altered brain function
Altered fluid balance and urinary frequency
Altered emotional state
Altered immune system
What may cause nausea and vomiting?
Correlated with high level of HCG so may be causative link
What are the key kidney changes in pregnancy?
Increased fluid retention and higher plasma volume
pass smaller volumes of urine more frequently
What may cause the altered immune response in pregnancy?
1. factors produced to suppress immune system e.g. decrease Th1 and Th2 response
2. placenta expressed unusal HLA on surface that is in contact with maternal tissues - HLA-G
What does embryo mean?
the baby up to 8 weeks of development
What timing is used by gynaecologists?
Last menstrual period
What timing is used by embryologists?
Point of fertilisation
2 weeks difference from LMP
In which trimester does the baby gain the most weight?
What develops late in pregnancy?
lungs, digestive system, immune system, brain (continous)
What are the functions of the placenta?
1. exchange of nutrients
2. connection (anchorage)
What is the primary subunit of placenta?
What is different about the vascular system in placenta?
Arteries - deoxygenated blood
Veins - oxygenated blood
because it acts as lungs for the foetus
Where does the placenta develop from?
Syncytiotrophoblast cells contain lacunae
Describe the development of placenta
Cytotrophoblast cells proliferate
First columanr structure formed (cytotrophoblast column) then branching
At the centre of each villus, mesenchymal cells - villus vascualr system develops from here
How does the placenta change by term
Maximise efficacy of nutrient transfer
What provides the nutrients to placenta and baby in first trimester?
What are the spiral arteries blocked by?
When does the cytotrophoblast plug break down?
10-12 weeks GA
Risky time frames as placenta is not fully anchored
What is the remodelling of spiral arteries?
vascular endothelium, smooth muscle cells replaced
widens the spiral arteries to support growing baby
begins during first trimester and finishes until 16-18 weeks of gestation