c. Blood Pressure. The average blood pressure(BP) of an infant at birth is
72/42. A drop in systolic BP of about 15 mm Hg the first hour after birth is common.
The newborn's BP may be taken with a Doppler blood pressure device. This greatly
d. Respirations. The respirations of a newborn infant are irregular in depth,
rate, and rhythm and vary from 30 to 60 beats per minute. Respirations are affected by
the infant's activity (that is, crying). Normally, respirations are gentle, quiet, rapid, and
shallow. They are most easily observed by watching abdominal movement because the
infant's respirations are accomplished mainly by the diaphragm and abdominal muscles
(see figure 7-1). No sound should be audible on inspiration or expiration.
Figure 7-1. Infant's respirations.
CHARACTERISTICS OF THE NEWBORN INFANT'S HEAD
The newborn infant's head represents one-fourth of his total body length. Its
circumference is equal to that of his abdomen or chest. The average size is 13" to 14"
(33-35 cm). The head is shaped or molded as it is forced through the birth canal in
a. Molding. During delivery, for the large head to pass through the small birth
canal, the skull bones may actually overlap in a process referred to as molding. Such
molding reduces the diameter of the skull temporarily. This elongated look usually
disappears a few hours after birth as the bones assume their normal relationships (see
b. Fontanels. The infant's skull is separated into six bones one from another
along the suture lines (see figure 7-3). Where more than two bones come together, the
space is called a fontanel. This is the unossified space or soft spot between the cranial
bones of the skull in an infant. The infant's pulse is sometimes visible there. The
anterior fontanel is located at the intersection of the sutures of the two parietal bones
and the frontal bones. It is diamond-shaped and strongly pulsatile. It normally closes at
9 to 18 months of age. The posterior fontanel is located at the junction of the sutures of