Pregnancy and Labour Flashcards
Which is the riskiest trimester
1st
When does a foetus become viable
24-26 weeks
When does placent change most
1st half of pregnancy
What happens to the mother and in which trimester
1st trimester Immune system Emotions Apetite hormones brain 2nd trimester Blood volume increase Increased blood pressure Increased blood clotting Altered Fluid Balance 3rd Increased weight Altered Joints
How much does progsterone and oestrogens increase by during pregnancy (by 3rd trimester)
x100
Which hormone peaks in the 1st trimester
HCG
What does HCG do?
Maintains endometrium, increases progesterone, stops menstrual cycle
What risks are there to the mother in pregnancy
Little risks in early parts
Unsafe for delivery
What is the conceptus
everything resulting from the fertilised egg: baby, placenta, fetal membranes, umbilical chord
what is an embryo
baby before it is clearly human
What is a foetus
baby for the rest of the pregnancy
What is an infant
after delivery
What scale is a summary of embryo staging
carnegie scale
How is pregnancy time frame counted
1st day of last menstrual period (bc its difficult to know when egg was fertilised)
What can mal-development tell us
identifies when conceptus is most vulnerable
What structures make up the placenta
cotyledons
What is the contents of a cotyledon?
Central villous tree
Branching of vessels outwardly to smaller subdivisions
Describe umbilical blood flow
Umbilical artery carries de-oxygenated blood, and the umbilical vein carries oxygenated blood
Functions of the placenta
separation, exchange, biosynthesis, immunoregulation, connection
What is spiral artery remodelling
removal of maternal endothelial and smooth muscle cells in the placenta to increase blood flow
If the placenta doesn’t form properly, what happens?
Miscarriage in late first trimester, early second trimester
pre-eclampsia, and foetal growth restriction
What is the clinical definition of labour
Fundally dominant contractions, cervical ripening and effacement
The processes of labour
cervical effacement and ripening co-ordinated myometrial contractions rupture of foetal membranes delivery of infant delivery of placenta contraction of uterus
What causes term labour?
unknown but maybe low progesterone, CRH or Oxytocin
What causes pre-term labour
intrauterine infection
intrauterine bleeding
multiple pregnancy
stress
How does cervical ripening occurr
recruitment of leucocytes, its an inflammatory process
PGE, IL-8,
How does contraction of myometrium occur?
Fundal dominance Increased co-ordination of contractions Increased power of contractions Key mediators Prostaglandin F2a (E2) levels increased from fetal membranes Oxytocin receptor increased Contraction associated proteins
How does rupture of fetal membranes occur?
Loss of strength due to changes in amnion basement component
Inflammatory changes, leukocyte recruitment
Modest in normal labour, exacerbated in preterm labour
Increased levels and activity of MMPs
Inflammatory process in fetal membranes
Which factor is massively important in signalling in labour
NFkappaB and causes a positive feedback which makes labour difficult to stop
What molecules does NFkappaB influence
COX-2 (prostaglandins - PGs), IL-8, IL-1b, MMPs, Oxytocin receptor, PG receptors; contraction-associated proteins
what 2 mediators rise in the last 3 weeks of pregnancy
CRH and Cox 2
