7-7.
CHARACTERISTICS OF THE NEWBORN CIRCULATORY SYSTEM
a. Blood Flow. When the umbilical blood stops flowing at birth, sudden
pressure differences occur within the circulatory system. These differences cause the
blood flowing to the lungs and liver to increase and the blood flowing through the
bypass channels to decrease. Peripheral circulation refers to residual cyanosis in
hands and feet. This may be apparent for one to two hours after birth and is due to
sluggish circulation. Blood is shunted to vital organs immediately after birth.
b. Blood Coagulation. During the first few days of life, the prothrombin level
decreases and clotting time in all infants is prolonged. This process is most acute
between the second and fifth postnatal days. It can be prevented to a large extent by
giving vitamin K to the infant after birth. With the ingestion of food, establishment of
digestion, and maturation of the liver, vitamin K is manufactured by the baby and
clotting time stabilizes within a week to ten days.
7-8.
CHARACTERISTICS OF THE NEWBORN RESPIRATORY SYSTEM
a. Until the infant's first breath of air is taken, the alveoli (air sacs) in the lungs
are in an almost complete state of collapsed. The lungs should be in this state because
the lung must not fill with amniotic fluid or other liquids. However, the fluid/liquid that
flows in the lungs during normal delivery is squeezed or drained from the infant lungs.
The major portion of the fluid is absorbed after delivery by the avcolar membranes into
the blood capillaries.
b. The most frequent cause of respiratory difficulty in the first few hours of birth
has been due to the too liberal use of sedatives, tranquilizers, analgesics, and
anesthetics that affect not only the mother, but pass over the placenta to the infant.
These drugs make the baby sleepy and disinclined to take the first breath.
7-9.
CHARACTERISTICS OF THE NEWBORN ENDOCRINE SYSTEM
The endocrine glands are considered better organized than other systems.
Disturbances are most often related to maternally provided hormones (estrogen, luteal,
and prolactin) that may cause the following conditions:
a. Vaginal discharge and/or bleeding may occur in female infants. This
discharge is white mucoid in color. Bleeding may occur as a result of withdrawal from
maternal hormones at the time of birth. There are usually only a few blood spots seen
on the diapers. The entire process terminates in one to two days.
MD0922
7-10