Care of the Newborn

Question 1

Name 6 functions of the placenta

Answer 1

1) Site of 02 transfer
2) Provides nutrition
3) Provides growth hormones
4) Controls fluid and electrolyte balance
5) Undertakes waste removal
6) Allows IgG to pass into the fetus

Question 2

Name 6 functions of the placenta

Answer 2

1) Site of 02 transfer
2) Provides nutrition
3) Provides growth hormones
4) Controls fluid and electrolyte balance
5) Undertakes waste removal
6) Allows IgG to pass into the fetus

Question 3

How do 2,3-DPG levels differ in pregnant and non-pregnant women and what effect does this have?

Answer 3

Pregnant women have 30% higher 2,3-DPG levels. 2,3-DPG binds to β-chains of Hb and reduces affinity of Hb for 02 and increases release. This shifts the 02 dissociation curve to the right.

Question 4

How does 2,3-DPG affect the fetus?

Answer 4

The fetal Hb contains γ chains rather than β chains. γ chains have a much lower affinity for 2, 3-DPG therefore the 02 dissociation curve of the fetus is further left

Question 5

What three factors allow effective oxygen donation to, and use, by the fetus?

Answer 5

1) Lower PaO2 in umbilical arteries than the maternal circulation creates an O2 gradient
2) The fetal haemoglobin (HbF) has a higher affinity for 02 than maternal haemoglobin (HbA) which facilitates uptake of released O2
3) Higher Hb in fetus allows effective carriage and release of oxygen despite increased affinity

Question 6

What vessel carries blood from the placenta to the fetus?

Answer 6

The umbilical vein which carries oxygenated blood at low pressure

Question 7

What vessels carry blood from fetus to placenta?

Answer 7

Umbilical arteries (x2) which carry deoxygenated blood at high pressure

Question 8

What vessels carry blood from fetus to placenta?

Answer 8

Umbilical arteries (x2) which carry deoxygenated blood at high pressure

Question 9

What three structures make the fetal circulation different to our own?

Answer 9

1) Foramen ovale
2) Ductus arteriosus
3) Ductus venosus

Question 10

Describe the location and purpose of the foramen ovale

Answer 10

The foramen ovale is a hole between the right and left atrium, which allows blood to be shunted from the right atrium to the left atrium thus bypassing the lungs.

Question 11

Describe the location and purpose of the ductus arteriosus

Answer 11

The ductus arteriosus is a small blood vessel connecting the pulmonary artery to the aorta. It allows the remaining blood in the right ventricle to bypass the lungs (RV only pumps 2/3 of cardiac output)

Question 12

Describe the location and purpose of the ductus arteriosus

Answer 12

The ductus arteriosus is a small blood vessel connecting the pulmonary artery to the aorta. It allows the remaining blood in the right ventricle to bypass the lungs (RV only pumps 2/3 of cardiac output)

Question 13

Describe the location and purpose of the ductus venosus

Answer 13

The ductus venosus is a small blood vessel connecting the umbilical vein to the fetal IVC. It allows a proportion of the oxygenated blood from the placenta to bypass the liver.

Question 14

What does the ductus arteriosus become after closure?

Answer 14

Ligamentum arteriosum

Question 15

What does the ductus venosus become after closure?

Answer 15

Ligamentum venosum

Question 16

What is ligamentum teres (also known as the round ligament of the liver)?

Answer 16

The remnant of the umbilical vein. The mesentery become the falciform ligament.

Question 17

Define functional residual capacity

Answer 17

The volume of air present in the lungs at the end of passive expiration

Question 18

What causes closure of the ductus arteriosus?

Answer 18

The ductus arteriosus is closed by increased partial pressure of oxygen. The effect is mediated by inhibition of prostaglandins.

Question 19

What happens to the umbilical arteries?

Answer 19

They constrict but some parts remain patent supplying the urinary bladder

Question 20

What are the nutrient requirements of a neonate?

Answer 20

Water - 150ml/kg/day
Calories - 110 kcal/kg/day
Protein - 1-2g/kg/day
Fat - including essential fatty acids
Minerals, vitamins and trace elements

Question 21

What is the predominant immunoglobulin found in breast milk?

Answer 21

IgA (the colostrum has particularly high levels of IgA)

Question 22

What is the predominant immunoglobulin found in breast milk?

Answer 22

IgA (the colostrum has particularly high levels of IgA)

Question 23

What two types of cancer does breast feeding reduce the risk of in the mother?

Answer 23

Breast cancer and ovarian cancer

Question 24

What two types of cancer does breastfeeding reduce the risk of in the mother?

Answer 24

Breast cancer and ovarian cancer

Question 25

Define preterm birth

Answer 25

Less than 37 weeks gestation

Question 26

Define:

1) Low birth weight (LBW)
2) Very low birth weight (VLBW)
3) Extremely low birth weight (ELBW)

Answer 26

1)

Question 27

Define still birth mortality rate

Answer 27

Fetus born with no signs of life at greater than or equal to 24 weeks old

Question 28

Define perinatal mortality rate

Answer 28

Stillbirths + deaths within the first 7 days of life per 1000 live births

Question 29

What is the stage of lung development at 7 weeks?

Answer 29

Pseudoglandular stage

Question 30

What is the stage of lung development at 18 weeks?

Answer 30

Canalicular stage

Question 31

What is the stage of lung development at 24 weeks?

Answer 31

Saccular stage, type II pneumocytes

Question 32

What is the stage of lung development at 32 weeks?

Answer 32

Alveolar stage

Question 33

Ventilation = ?

Answer 33

Ventilation = tidal volume x respiratory rate

Question 34

What is perinatal asphyxia? What is the resulting condition called in neonates?

Answer 34

Perinatal asphyxia is when gas exchange, either pulmonary or placental, is compromised or ceases altogether. The resulting neonatal condition is called hypoxic ischemic encephalopathy.

Question 35

What may cause failure of gas exchange across the placenta?

Answer 35

Excessive or prolonged uterine contractions, placental abruption or a ruptured uterus

Question 36

What may cause interruption of umbilical blood flow?

Answer 36

Cord compression, including shoulder dystocia; and cord prolapse.

Question 37

What can cause inadequate maternal placental perfusion?

Answer 37

Maternal hypotension or hypertension - often with IUGR

Question 38

When do the clinical manifestations of hypoxic-ischaemic encephalopathy start? And how are they graded?

Answer 38

Immediately or up to 48 hours post asphyxia. They are graded as mild, moderate or severe.

Question 39

Describe mild clinical manifestations of hypoxic ischaemic encephalopathy

Answer 39

The infant is irritable, responds excessively to stimulation, may have staring of the eyes & hyperventilation and has impaired feeding.

Question 40

Describe moderate clinical manifestations of hypoxic ischaemic encephalopathy

Answer 40

The infant shows marked abnormalities of tone and movement, cannot feed and may have seizures.

Question 41

Describe severe clinical manifestations of hypoxic-ischaemic encephalopathy

Answer 41

There are no normal spontaneous movements or response to pain; tone in the limbs may fluctuate between hypotonia and hypertonia; seizures are prolonged and often refractory to treatment; multi organ failure is present.

Question 42

Neuronal damage may be primary from neuronal death or may be delayed from…

Answer 42

Reperfusion injury, causing secondary neuronal death

Question 43

What treatment may offer neuroprotection from reperfusion injury?

Answer 43

Mild hypothermia (33 to 34 degrees for 72 hours by wrapping in a cooling blanket)

Question 44

What does aEEG stand for? and what does it monitor?

Answer 44

Amplitude-integrated electroencephalogram. It monitors cerebral function and can detect abnormal background activity to confirm early encephalopathy or identify seizures.