Labour Flashcards
What is a term delivery?
37-41 weeks gest
what is a mod or late pre term delivery?
32-37 weeks gest
What is a very pre term delivery
28-32 weeks gest
What i an extremely pre-term delivery?
< 28 weeks gest
What are the 3 stages of labour?
Phase 1: Uterine contractions and cervical changes
Phase 2: Delivery of the of the foetus
Phase 3: (30 min) : Delivery of the placenta
What are the foetal membranes?
the fused chorion and amnion
what are the 3 key anatomical tissues involved in labour?
cervix, myometrium, and foetal membranes
What is cervical effacement?
cervix turns from rigid to flexible
What are the 3 mechanisms involved in cervical effacement?
- remodelling of the ECM
- leukocyte recruitment
- inflammation (PGE2 and IL8)
define the mechanism of uterine contraction
co-ordinated myometrial contraction with fundal dominance
uterus is squeezed from the top down, with increasing co-ordination and power
key mediators of uterine contraction
Prostaglandin F2 alpha from fetal membranes
Oxytocin receptor activation
activation of CAPs (contraction associated proteins)
What changes occur during placental delivery and why?
heamostatic changes to prevent maternal haemorrhage - increased clotting ad powerful uterine contraction
main pro-inflammatory transcription factor involved in labour
NFkB
What is the role of PAF and CRH in labour?
Platelet Activating Factor is a component of lung surfactant - sign of fetal maturity
PAF and CRH rise before labour and upregulate inflammatory pathways
describe the changes in progesterone effects during pregnancy and labour
NFkB and P have opposing effects
PRB mediates effects of P in pregnancy
PRA reduces effect of P in labour
at term PRA:B ratio increases causing P withdrawal inducing labour
