labour or partuition

what does nulliparous mean?

never given birth

what does multiparous mean?

have given birth to more than child

what is another term for labour?

partuition

how many stages of labour are there?

three

when does the first stage of labour occur from and until?

from beginning of labour until the cervix is fully dilated (around 10cm)

how frequently do first stage contractions occur?

every 2-3 minutes

what happens to the foetal membranes in the first stage?

they rupture if they had not already

what are the 2 phases of the first stage of labour?

- latent phase

- active phase

what happens in the latent phase?

slow cervical dilation up to 4cm dilated

how long does the latent phase last?

several hours

what happens in the active phase?

faster cervical dilation until 10cm dilatation is reached

how long does the active phase last?

fewer hours, no more than 16

when does the second stage of labour occur from and until?

from full dilatation of cervix until foetus is expelled

what are the two stages of the second stage?

- passive stage

- active stage

what happens in the passive stage? (3)

- foetus is pushed until its head reaches the pelvic floor

- the woman experiences the desire to push

- rotation and flexion of head are complete

how long does the passive stage last?

a few minutes

what happens in the active stage?

the pressure of the foetal head on pelvic floor causes the woman to actively push alongside the contractions

how are the muscle fibres of the myometrium adapted to aid labour?

they do not fully relax between contractions

how does not fully relaxing between contractions aid labour?

gradually reduces the uterine capacity and hence increases the pressure to aid expulsion of foetus

what hormone increases contraction force?

prostaglandins

how do prostaglandins increase contraction force?

increase amount of intracellular calcium being released per action potential

what hormone increases contraction frequency?

oxytocin

how does oxytocin increase contraction frequency?

lowers the threshold for action potentials, so they can occur more frequently

how long does the active stage last before delivery in nulliparous women?

40 minutes

how long does the active stage last before delivery in multiparous women?

20 minutes

what happens after delivery of the head and why?

it rotates by 90 degrees to assist with delivery of shoulders

which shoulder has to come first?

anterior shoulder, comes under the pubic symphysis

how does the body aid delivery of anterior shoulder?

flexes laterally and posteriorly

how does the body aid delivery of the posterior shoulder?

flexes laterally and anteriorly

what happens after both shoulders are delivered?

the rest of the body is fairly easily delivered

when does the third stage of pregnancy last from and until?

from delivery of foetus until delivery of placenta

what happens in the third stage of labour?

- uterine muscle fibres contract to compress the blood vessels supplying the placenta

- the placenta pulls away from the uterine wall and is delivered

how much blood is usually lost in the third stage?

500ml blood loss

how is bleeding controlled in the third stage? (3)

- contraction of uterus constricts blood vessels in myometrium

- pressure is exerted on placental site once it has been delivered by walls of contracted uterus

- normal blood clotting mechanism

what terminology is used to describe how far the head is into the pelvis?

engagement

how do you measure engagement?

by seeing how many 1/5ths of the baby's head you can palpate above the pelvis

- if you can palpate 3/5s then the baby is 2/5s engaged

what is the terminology used to describe the babies head in relation to the ischial spine?

station

how would you measure station?

0 = head is directly at ischial spine

-2 = head is 2cm above ischial spines

2 = head is 2cm below ischial spines