Gestation
time foetus is carried in uterus
Labour
sequence of events preceding parturition
Parturition
process where foetus is expelled from mother
What happens in the weeks leading up to labour
describe 3 main changes
hormonal changes
- cause ligaments of pelvis to soften
- increase irritability and contractibility of uterus
contractions
- 3 months before labour
- irregular weak contractions that become more frequent and stronger
foetal moves into birthing position
- head moves down into cervix, body faces one side with knees drawn up to its abdomen and legs crossed
At what point does birth begin
(onset of labour)
contractions become strong and occur every 30 mins
Why is the foetal birthing position important
2
- allows head to be delivered first so it acts as a wedge to force open cervix and vagina
- allows foetus to begin breathing
First stage of labour
1
from onset of labour to complete dilation of cervix
Labour pains
3
- involunatary contractions of uerine walls
- travel from top part of uterus towards cervix
- shortens muscle fibres of uerus which pulls on cervix to shorten it
Complete dilation of cervix
2
opening of cervix
approx 10cm
What does complete dilation of cervix allow foetus to do
move deeper into pelvis with its head pushed forcefully against cervix
Birth canal
passage made up of uterus, cervix and vagina
Other events that occur in the first stage of labour
2
- a ‘show’ - discharge of mucus plug (thick and stringy)
- ‘breaking of waters’ - amniotic sac ruptures releasing fluid
Second stage of labour
description
from full dilation of cervix until foetus delivery
expulsion
Describe what happens during the second stage of labour
5
- foetus moves thru cervix, head stretches vagina -> stimulating contraction of mother’s abdominal muscles
- head of foetus turns to face mother’s back
- each contraction makes foetus’ head advance a bit - in between contractions it retracts
- head strenches vaginal entrance and perineum eventually
- once head emerges, turns sideways to face mother’s hips (allows shoulders and rest of body to move thru more easily)
What happens to the mother during second stage of labour
2
- high pulse
- sweat
What might happen to the foetus’ head during expulsion
3
- pressure on head may put it out of shape
- no brain damage as bones of skull are flexible/pliable
- head resumes to normal shape a few days after birth
Perineum
tissues between vagina and anus
Vernix
protective waxy material that baby is covered in at birth
Third stage of birth
delivery of the afterbirth (amnion, chorion, placenta and umbilical cord)
umbilical cord clamped -> arteries and veins contract
uterus continues to contract for expulsion of these
How is the umbilical cord clamped
tied in 2 places and cut between the ties
What remains in the abdomen as a scar of the umbilical cord
navel/umbilicus
Why is little blood lost during birth
3
- placental blood vessels vasoconstrict
- contractions of uterus squeeze shut uterine vessels which supply placenta
- blood clots form
Vaginal birth
1
relies on body’s natural ability to deliver baby
Caesarean birth
3
- using surgery to deliver baby
- cut made into mother’s abdomen, uterus and baby lifted out
- when vaginal birth not safe/possible (multiple births, large foetus, high bp)
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Cell Division53
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Male Reproductive System32
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Cancer22
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Female Reproductive System63
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STI's48
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Fertilisation11
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Contraception47
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ART's31
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Development - Embryonic, Placental & Foetal55
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Cell Differentiation13
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Labour38
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DNA36
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Diagnosis of Foetal Health19
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Protein Synthesis30
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Epigenetics & Gene Imprinting24
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Genetics & Inheritance30
