Pregnancy and Birth

Question 1

What is the definition of labour?

Answer 1

• on-set of regular uterine contractions leading to progressive effacement (stretching and thinning of the cervix) and dilatation of the cervix

Question 2

What generally occurs to the 3 hormones below during labour:

• estrogen
• progesterone
• oxytocin

Answer 2

• estrogen = small increase
• progesterone = decrease
• oxytocin = large increase

Question 3

Where is oxytocin released from?

Answer 3

• posterior pituitary gland

Question 4

Prostaglandins are a group of lipids made at sites of tissue damage or infection that are involved in dealing with injury and illness. What happens to the levels of this during labour?

Answer 4

• increased levels

- secreted by the decidua

Question 5

Prostoglandin levels are increased during labour and are produced and released by the decidua. What is the decidua?

Answer 5

• part of the endometrium

- undergoes special modifications in preparation for and during pregnancy and is cast off at parturition

Question 6

During labour the following changes occur

• estrogen = small increase
• progesterone = decrease
• oxytocin = large increase
• prostoglandins = increase

What is the purpose of these changes?

Answer 6

• dilate the cervix and initiate uterine contractions

Question 7

During labour there is a mechanical change that initiates uterine contractions and dilation of the cervix. What causes the mechanical stimulation that initiates labour?

Answer 7

• babies head or other body (presenting part) part pressing on cervix

Question 8

What is the latent phase of labour?

Answer 8

• cervix becomes soft and thin as it gets ready to dilate

Question 9

Following the latent phase of labour, labour can be divided into 3 stages. What are the 3 stages of normal labour?

Answer 9

1st stage = latent phase followed by active labour with regular, strong contractions, cervix begins to open
2nd stage = cervix is fully dilated, head descends the vagina, delivery of the baby
3rd stage = delivery of the placenta & membranes

Question 10

Do nulliparous women (1st time mother) or multiparous women (previous deliveries) generally deliver quickest?

Answer 10

• multiparous women

Question 11

When the uterus contracts and relaxes what happens to the uterine muscle fibres, and how does this relate to pain?

Answer 11

• contraction = muscle fibres shorten and pain is felt

- relaxation = muscle fibres relax and pain subsides

Question 12

What is progress of labour determined by?

Answer 12

• progress of the babies head in relation to the ischial spine
• a score of -5 indicates the baby is not that progressed
• a score of +5 indicates a baby is very progressed

Question 13

What is amniotic fluid?

Answer 13

• protective liquid contained by the amniotic sac

Question 14

Amniotic fluid is the fluid that is contained within the amniotic sac. What are the 4 main functions of amniotic fluid?

Answer 14

• allow foetus to move around ensuring bone growth
• development of the lungs
• maintains temperature around the baby, protecting from heat loss
• protection from outside injury by cushioning sudden blows or movements

Question 15

How does amniotic fluid help the lungs develop?

Answer 15

• breathe in fluid to expand the lungs
• works to increase lung volume
• when born there is a pressure change which expels the fluid

Question 16

What is meconium?

Answer 16

• first faeces of the newborn
• meconium aspiration syndrome occurs when a newborn breathes a mixture of meconium and amniotic fluid into the lungs around the time of delivery
• if occurs while in uterus can indicate the baby is under stress

Question 17

As labour progresses, which is assessed using the descent of the foetus head in relation to the ischial spines​, what happens to the babies position as it moves through the pelvis?

Answer 17

• twists and turns, called the mechanism of labour

Question 18

As labour progresses, which is assessed using the descent of the foetus head in relation to the ischial spines​, the baby twists and turns, called the mechanism of labour. Why does this occur and does it need assistance?

Answer 18

• helps baby navigate through the shape and curves of the pelvis
• this is a ‘hands off’ moment as could cause problems

Question 19

If a mother becomes stressed during labour this can cause an increase in adrenalin. Why is this bad in a woman that is in labour?

Answer 19

• adrenalin decreases prolactin

- prolactin stimulates the release of oxytocin which is crucial for uterus contractions during labour

Question 20

What is crowning?

Answer 20

• the baby’s head can be seen completely at your vulva

- most painful time for the mother and perineum needs to be protected

Question 21

What is the Ferguson reflex?

Answer 21

• a neuroendocrine reflex comprising the self-sustaining cycle of uterine contractions initiated by pressure at the cervix, more precisely, the internal end of cervix, or vaginal walls

Question 22

What identifies the end of the 2nd stage of labour?

Answer 22

• expulsion of the foetus

Question 23

The 3rd stage of delivery is to deliver the placenta. Why is this stage of labour really important?

Answer 23

• most dangerous to the woman

- always a risk of haemorrhage

Question 24

Following delivery of the baby, what happens to uterus?

Answer 24

• uterine muscle fibres remaining shortened after contracting during labour
• the basal portion of the uterus becomes thicker and pulls up the dilating cervix over the presenting part

Question 25

Following delivery of the baby the uterine muscle fibres remain shortened after contracting during labour. The basal portion of the uterus becomes thicker and pulls up the dilating cervix over the presenting part. If this does not occur this is called uterine atony. Why is this dangerous?

Answer 25

- the placenta does can tear off the uterine | - the placenta has an extensive blood flow, so rupture of this can be dangerous

Question 26

What is the average time period that it can take for the placenta to be delivered?

Answer 26

- 1 hour

Question 27

What is a retroplacental clot?

Answer 27

- bleeding may occur but the blood may clot between the placenta and the wall of the uterus - this limits the vaginal bleeding

Question 28

The blood around the placenta can be cut off. What facilitates the contraction of the blood vessels of the placenta?

Answer 28

- myofibrils (small muscle fibres) of the uterus contract around the blood vessels - create ’living ligatures' - placenta essentially dies and drops off

Question 29

Why is the 3rd stage where the placenta is delivered described as a physiological process?

Answer 29

- placenta is naturally delivered with contractions

Question 30

The 3rd stage where the placenta is delivered is often described as a physiological process, where the placenta is naturally delivered with contractions. However, if this is not the case there needs to be active management of the 3rd stage of delivery, which can divided into 3 stages. What are the 3 stages?

Answer 30

1st stage = drug is provided (normally oxytocics, synthetic oxytocin) 2nd stage = the cord is clamped 3rd stage = pressure is applied to the uterus and the cord is pulled

Question 31

During the 3rd stage if the placenta is not delivered it needs to be actively delivered. During this why should the cord not be pulled straight away?

Answer 31

- synthetic oxytocin needs to be administered | - if the cord is pulled there is risk of uterine inversion

Question 32

What anatomical position can be used to identify if the uterus has contracted following the delivery of the placenta?

Answer 32

- umbilical cord

Question 33

What natural process can increase the production of endogenous oxytocin?

Answer 33

- sight and smell of the baby | - skin-to-skin contact with the baby

Question 34

Why is the continued production and secretion of oxytocin during stage 3 of labour (delivery of the placenta) important?

Answer 34

- oxytocin increases uterine contractions | - uterine contraction helps the placenta separate from the uterus

Question 35

The maternal side of the placenta has something called cotyledons, what are these?

Answer 35

- lobes with a main stem of a chorionic villus as well as its branches and subbranches - deliver nutrients from the mother to the baby

Question 36

What are the 2 main membranes of the placenta?

Answer 36

1 - chorion (surrounds amnion) | 2 - amnion (surrounds amniotic fluid)

Question 37

The chorion membrane is a thick, opaque, friable membrane. It is the closest to the maternal side of the placenta. What is the chorion membrane layer derived from?

Answer 37

- trophoblast and is a continuous with the edge of the placenta - closely adherent to the decidua and forms the base of the placenta

Question 38

The amnion membrane is the layer that lies close to the foetus and surrounds the amniotic fluid and is a tough and translucent membrane. What cells does the amnion membrane derive from and what does this layer secrete?

Answer 38

- amnion is derived from the inner cell mass of the blastocyst - amnion secretes amniotic fluid and protects the placenta and foetus from injury and ascending infection

Question 39

What is antepartum haemorrhage?

Answer 39

- genital tract bleeding from 24+0 weeks’ gestation

Question 40

Antepartum haemorrhage is defined as genital tract bleeding from 24+0 weeks’ gestation. One of the most common causes is placenta praevia, what is this?

Answer 40

- placenta attaches inside the uterus but in an abnormal position near or over the cervical opening

Question 41

Antepartum haemorrhage is defined as genital tract bleeding from 24+0 weeks’ gestation. One of the most common causes is placenta abruption, what is this?

Answer 41

- placenta separates from the inner wall of the uterus before birth - staves the baby of O2 and nutrients - causes heavy bleeding in the mother

Question 42

Primary and secondary postpartum haemorrhage (PPH) is one of the leading causes of maternal death. What is the difference between primary and secondary PPH?

Answer 42

- primary PPH = loss of >500 ml blood from the genital tract within 24 hours of the birth of a baby - secondary PPH is defined as abnormal or excessive bleeding from the birth canal between 24 hours and 12 weeks postnatally

Question 43

When a woman is in labour and the term breeched is used, what does this mean?

Answer 43

- baby is head up and feet facing the cervix (opposite way it should be)

Question 44

What is a cord prolapse?

Answer 44

- umbilical cord slips down in front of the baby after the waters have broken - cord can then come through the open cervix (entrance of the womb) - usually happens during labour but can occur when the waters break before labour starts