Chapter 12: Birth & Baby Changes

Question 1

Pre-labour

Answer 1

Before labour, foetus hand rests in mother’s pelvis, uterus contractions strengthen, cervix softens & shorten, starting to open from hormonal changes. Foetus facing right or left with knees drawn up and legs crossed.

Question 2

Pre-labour (foetus head)

Answer 2

Before birth foetus head changes position downward to rest in pelvis bowl for birth, allows head to be delivered 1st and to force open cervix and vagina. Allows breathing even before foetus is out.

Question 3

Stage 1: Cervix dilation (wider)

Answer 3

Uterus contractions gradually becomes stronger eventually happens every 30 mins = beginning of birth (labour pains).

Question 4

Stage 1: 1.

Answer 4

Cervix dilation (8-9 hours in 1st labour, 4 hours after).

Question 5

Stage 1: 2.

Answer 5

Peristalsis like contractions move down uterus to cervix.

Question 6

Stage 1: 3.

Answer 6

These contractions pull on cervix and foetus head forcefully pushes cervix to open.

Question 7

Stage 1: 4.

Answer 7

Cervix dilates forming 1 birth canal: uterus, cervix, vagina where foetus will pass aided by uterus contractions and abdominal muscles

Question 8

Stage 2: Expulsion (birth)

Answer 8

20 mins-2 hrs. Stage begins with amniotic sac breaking and gush of fluid from vagina.

Question 9

Stage 2: 2.

Answer 9

Foetus head pushes through vagina stretching it activating more forceful abdominal muscles and uterus contractions (positive feedback loop).

Question 10

Stage 2: 3.

Answer 10

Baby twists to face mother’s back.

Question 11

Stage 2: 4.

Answer 11

Very intense contraction sequence: rest, contraction as head gradually goes out.

Question 12

Stage 2: 5

Answer 12

Once heads out baby rotates back allowing shoulders through more easily. Then born.

Question 13

Baby’s head

Answer 13

Baby’s head maybe out of shape because pressure to head. Brain isn’t damaged as bones of baby’s skull is flexible. Head returns normal in few days.

Question 14

Stage 3: Afterbirth

Answer 14

Now baby can breathe with own lungs although still connected to placenta by umbilical cord. Amnion, chorion, placenta still in uterus.

Question 15

What happens to the umbilical cord afterbirth

Answer 15

Umbilical cord is clamped and (if cut) few days after forms umbilicus (short stub).

Question 16

Vernix

Answer 16

Waxy material covering baby as protective layer.

Question 17

Foetal circulation before birth

Answer 17

Lungs don’t function. Oxygen comes from placenta.

Foetus circulation must change when born. Before birth everything relies on mom.

Question 18

Ductus venosus

Answer 18

Hollow tube, allows oxygenated blood in umbilical vein to bypass liver straight to vena cava for foetal circulation

Question 19

Ductus arteriosus

Answer 19

Blood returning to foetus heart can’t go to lungs because non-functional. Instead flows by ductus arteriosus bypassing lung allowing blood in pulmonary artery to aorta.

Question 20

Foramen ovale

Answer 20

Oval opening allowing blood in right atrium to flow directly to left atrium. Located where most blood flows (between atria) it’s beneficial as the blood is highly oxygenated and can flow directly to developing foetal tissue quickly.

Question 21

Foetal circulation afterbirth: Like normal human.

Answer 21

Now, baby has functional body, doesn’t rely on placenta.

Lungs and liver must function (by blood flowing through them). Therefore it’s important that ductus venosus & arteriosus, foramen ovale are closed.

Question 22

If foramen ovale doesn’t close?

Answer 22

Baby maybe born ‘hole in heart’. Causes mixture of blood causing breathing problems, heart palpitations.