Newborn adaptations

Question 1

name 4 factors that are thought to initiate the first breath at birth

Answer 1

• Uterine contractions in the second stage of labour.
• Compression of the chest wall during birth and the recoil of the chest wall immediately after birth.
• Chemoreceptor stimulation by reduction in oxygen and increase in carbon dioxide in the blood.
• Cold, light noise and touch are secondary contributors to stimulate a baby to breathe.

Question 2

How many mls of pulmonary fluid per kg do the lungs hold in a term fetus?

Answer 2

25mls/kg. This is partially expelled at birth. The rest is absorbed by the lymphatic and pulmonary vessels and returned into the cardiovascular system.

Question 3

What do most infants do for respiration within their first few seconds after birth?

Answer 3

They gasp. Then establish regular respiration within minutes.

Question 4

When do infants reach peak respiration rate?

Answer 4

By 60 minutes post birth

Question 5

when does the fetus start to make surfactant in the lungs?

Answer 5

From about 32 weeks gestation increasing amounts of surfactant is produced to prepare lungs for effective gas exchange after birth.

Question 6

when is surfactant required and why?

Answer 6

the first breath results in lungs expanding and the pulmonary vessels enlarging, it is the hardest breath and requires surfactant to help break surface tension. This facilitates inspiration and prevents the alveoli from collapsing with each expiration.

Question 7

Surfactant is a mixture of?

Answer 7

lipids and proteins which is secreted by the epithelial type II cells into the alveolar space.

Question 8

how does the fetus prepare its respiration for the transition to extrauterine life?

Answer 8

the fetus exercises its muscles of respiration by making irregular fetal breathing.

Question 9

physiological hypoxia accompanied by physiological hypercarbia establishes what for the newborn?

Answer 9

a new respiratory drive within the medulla oblongata to sustain pulmonary ventilation.

Question 10

the newborn has a core internal body temperature of?

Answer 10

36.5-37.5 C

Question 11

clamping of the umbilical cord is a signal that increases what?

Answer 11

renal function and kidneys take over the control of fluid, electrolyte, acid-base balance and the excretion of metabolic waste.

Question 12

what percentage of weight loss in a newborn is considered physiological?

Answer 12

7%

Question 13

how many times do most newborns feed in 24hours?

Answer 13

8-12

Question 14

what is considered normal newborn weight gain by 6 weeks?

Answer 14

1kg over birth weight

Question 15

what is considered a late sign of hunger?

Answer 15

crying

Question 16

In the first 24hours, how much colostrum is a baby required to have each feed?

Answer 16

0.5mls. Half a teaspoon

Question 17

After the first 24 hours, how much colostrum does a baby require each feed?

Answer 17

1ml. A teaspoon

Question 18

By 48 to 72 hours, how much breastmilk is a baby required to have?

Answer 18

Supply rises rapidly to about 200mls per day

Question 19

By 72 to 96 hours, how much breastmilk is a newborn required to have?

Answer 19

Supply rises to 500-800mls per day

Question 20

how many wet nappies is a newborn required to have in a day?

Answer 20

At least 1 wet nappy for as many days as the baby is old, up to 7 days