Gestational Age and Newborn Reflexes

The exam should be conducted with the infant undressed and lying under a radiant warmer.

While the process is painless, some infants may become agitated with continued handling.

If the baby becomes upset, allow a few minutes of rest before continuing.

Indicate your findings on the form by making an X in the appropriate box.

If you are performing the second assessment at 12 hours, mark an O in the square.

This makes it easy to differentiate for age if the parameters change.

Begin by observing the infant's resting supine posture.

As the fetus matures, muscles strengthen and the natural tendency to flexion at rest begins

to be asserted.

The very immature lie with arms and legs in full extension.

The more mature the newborn, the greater degree of flexion.

Next is the square window.

Steady the infant's forearm in an upright position while gently pressing the palm of

the infant's hand down.

The measurement is the degree of the angle formed by the palm in the forearm at the wrist.

Resistance to flexion of the wrist as well as the ankle decreases as the expected date

of delivery approaches due to the influence of the same hormones that cause the relaxation

of maternal structures in preparation for delivery.

The wrist of a premature infant resists flexion, while that of the post-mature infant will

allow the hand to fold flat against the wrist.

Now measure arm recoil.

With the infant on his back, grasp both hands and place them in a fully flexed position

and hold for five seconds, then pull the arms into full extension and release.

Observe to what degree the hands and forearms recoil using the drawings on the chart as

a guide.

The difference between three and four is not the degree of flexion, but rather the force

of the response.

For full points, the recoil is an instant, brisk return to full flexion.

The next category is the popliteal angle.

For an accurate measurement, it's necessary that the infant's pelvis be flat on the

examining surface.

Use the heel of one hand to stabilize the pelvis and the fingers of that same hand to

hold the top surface of the infant's thigh against the abdomen.

With the index finger of the other hand, gently lift upward at the heel and measure the angle

formed by the knee joint.

The fifth measurement is called the scarf sign.

With the infant supine, grasp one arm at the wrist and draw it across the body.

It is permissible to assist by lifting the elbow and guiding the arm.

However, the shoulder is not to be lifted off the examining surface.

Points are based on where the elbow rests in relation to the midline.

The last neuromuscular measurement is the heel to ear.

Again, the infant is supine.

Hold the infant's foot and lift the leg over the abdomen as close to his head as possible

without force.

The pelvis must remain flat against the exam surface.

Use the pictures on the form as a scoring guide.

The remaining seven parameters focus on observations related to physical development.

Each is known to progress at predictable rates during fetal development, making them excellent

markers of gestation.

First is the skin.

In the very premature, the skin is red and feels sticky.

The fetus that is born nearer to term has skin that is more firm and smooth with visible

veins.

Closer yet to term, veins fade and disappear.

Visible cracking around the wrists and ankles may be seen in the term infant.

The postmature infant often has a cracked skin surface over the entire body.

A skin attribute related to gestation but not noted on the Ballard is the vernix caseosa.

Vernix is a thick, cheesy substance made of sebum and sloughed skin cells.

It begins to form at about 20 weeks, increasing as pregnancy progresses.

Formation decreases near term, and most term and post-term infants have little or no visible

vernix as it has been washed away by the amniotic fluid.