Physiological labour Flashcards
What is the normal position of the uterus?
anteverted and anteflexed
What is the biological term for labour?
parturition
What environment is best for normal physiological birth?
needs to be private, oxygenated, calm, with partner
- need high levels of oxytocin - replicate the setting you conceived the baby
What is spontaneous abortion (miscarriage) ?
labour before 24 weeks
What is pre-term labour?
labour before the 37th week
What processes does the expulsion of the foetus require?
- creation of the birthing canal
- the release of the structures which normally retain the fetus in utero
- The enlargement and realignment of the cervix and vagina
- expulsion of the fetus
- expulsion of the placenta and changes to minimise the blood loss from the mother
What is labour?
the process where the foetus placenta and membranes are expelled through the birth canal
What are the 3 stages of labour?
1 - onset of regular contractions until the cervix is fully dilated - 10cm
2 - begins when the cervix is fully dilated and ends with the birth of the baby
3 - from the birth of the baby to the delivery of the placenta and membranes and bleeding is controlled
What happens in the first stage of labour?
- foetus, placental membranes and uterus increase in size
- minimum of 2 contractions every 5 minutes
- painful enough to stop talking
What is the preferred position of the fetus?
head first - cephallic
What is the latent phase?
cervix dilation up to 4cm
What is active labour?
4cm-10cm
How does the foetus present?
presentation describes which part of the fetus is adjacent to the pelvic inlet
-if the baby lies longitudinally, the presenting part may be the head (cephalic) or the breech (podalic)
What is engagemnt>
around 36 weeks - fundal height is high in the ribs but it drops lower down as the head starts to engage into the pelvis
What occurs in pre-labour? (getting ready for the baby)
- Expansion of the lower segment
- foetal head engages
- symphysis pubis widens and scare-iliac joints relax
- pelvis floor relaxes
- increased vaginal secretions
- frequency of micturition
- Braxton hicks
- high levels of relaxin and progesterone cause pregnancy gait - softening of ligaments and muscles
What changes in the gap junctions?
Gapa junctions increase in number and act as electro-chemical signalling system between cells which sets up the braxton hicks contraction
What does oxytocin do?
- Acts on the myometrium to make it more sensitive and allow it to contract
- postivie feedback loop occurs when the foetal head presses on the cervix causing more oxytocin to be released from the posterior pituitary gland to get contractions
What does cervical softening involve?
The cervix has a high connective tissues content of collagen fibres embedded in a proteoglycan matrix - in ripening, you get a reduction in collagen and increase GAG which decreases the aggregation of collagen fibres which get loosened
What is the pelvic inlet bound by?
posteriorly - sacral promontory
laterally - ilio-pectinal line
anteriorly - superior pubic rams and pubic symphysis
What happens if you have too much adrenaline?
It will work against the oxytocin hence why you need a calm environment
How is the birth canal formed?
-pelvic ligaments soften
-dilation of the cervix and retracted anteriorly
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