The doctor usually gives the newborn a thorough physical examination within the first 24 hours of life. The examination begins with a series of measurements, including weight, length, and head circumference. The average weight at birth is 7 pounds (3.2 kilograms), and the average length is 20 inches (51 centimeters), although there is a wide range that is considered normal. Then the doctor examines the newborn's skin, head and neck, heart and lungs, and abdomen and genitals and assesses the newborn's nervous system and reflexes. Doctors also routinely do screening tests to detect problems they cannot see during the physical examination (see Newborn Screening Tests).
Doctors examine the skin and note its color. The skin is usually reddish, but the fingers and toes commonly have a bluish tinge because of poor blood circulation during the first few hours. Sometimes, there are tiny reddish-purple spots (called petechiae) on parts of the body that were pressed hard during delivery. However, petechiae on all parts of the body could be a sign of a disorder and need to be evaluated by the doctor. Dryness and peeling of the skin often develop within days, especially at wrist and ankle creases.
Many newborns develop a rash about 24 hours after birth. This rash, called erythema toxicum, consists of flat, red splotches and usually a white, pimple-like bump in the middle. It is harmless and disappears in 7 to 14 days.
Doctors examine the newborn's head, face, and neck for any abnormalities. Some abnormalities occur during delivery. Other abnormalities may be caused by a birth defect.
A normal head-first delivery leaves the head slightly misshapen for several days. The bones that form the skull overlap, which allows the head to become compressed for delivery. Some swelling and bruising of the scalp is typical. Sometimes bleeding from one of the bones of the skull and its outer covering causes a small bump on the head that disappears in a few months (called a cephalhematoma). When the baby is delivered buttocks, genitals, or feet first (breech delivery), the head is usually not misshapen. However, the buttocks, genitals, or feet may be swollen and bruised. Delivery of a baby in the breech position is now usually avoided. When the baby is in the breech position, doctors usually recommend a cesarean delivery or C section (the surgical delivery of a baby by incision through a woman's abdomen and uterus), which minimizes danger to the baby.
Pressure during a vaginal delivery may bruise the newborn's face. In addition, compression through the birth canal may make the face initially appear asymmetrical. This asymmetry sometimes results when one of the nerves supplying the face muscles is damaged during delivery. Recovery is gradual over the next few weeks.
The delivery process might also cause subconjunctival hemorrhages (broken blood vessels on the surface of the eye) to form in the newborn's eyes. These hemorrhages are common, do not need treatment, and typically go away within 2 weeks.
Doctors examine the ears and note whether they are properly formed and in the correct place. For example, low-set or incorrectly formed ears may mean the newborn has a genetic disorder and/or hearing loss.
Doctors also examine the mouth for problems. Rarely, newborns are born with teeth, which may need to be removed, or a cleft lip or cleft palate. Doctors check to see whether newborns have an epulis (a noncancerous growth on the gums) because these growths can cause feeding problems and may block the airways.
The neck is examined for swelling, growths, and twisting or spasms.
(See also Birth Defects of the Heart.)
The doctor listens to the heart and lungs through a stethoscope to detect any abnormality. Doctors are able to hear abnormal sounds such as a heart murmur or lung congestion. The doctor inspects the newborn's skin color. A blue color of the face and torso may be a sign of congenital heart or lung disease. The rate and strength of the pulse is checked. Doctors watch the newborn breathe and count the number of breaths in a minute. Grunting and/or flaring nostrils with breathing and breathing too fast or too slow can be signs of problems.
The doctor examines the general shape of the abdomen and also checks the size, shape, and position of internal organs, such as the kidneys, liver, and spleen. Enlarged kidneys may indicate a blockage to the outflow of urine.
The doctor examines the genitals to ensure the urethra is open and in the proper location. The doctor also checks to make sure the genitals are clearly male or female. In a boy, the testes should be present in the scrotum. In a girl, the labia are prominent because of exposure to the mother's hormones, and they remain swollen for the first few weeks. Secretions from the baby's vagina that contain blood and mucus are normal. The doctor examines the anus to make sure the opening is normally placed and not sealed shut.
(See also Birth Defects of the Brain and Spinal Cord.)
The doctor looks at the newborn's level of alertness, muscle tone, and ability to move arms and legs equally. Unequal movement could be a sign of an abnormality of the nerves (such as a nerve palsy).
Doctors test the newborn's reflexes using various maneuvers. A newborn's most important reflexes are the Moro, rooting, and sucking reflexes.
The doctor examines the flexibility and mobility of the arms, legs, and hips and checks to see whether the newborn has broken any bones during delivery (particularly the collar bone) or has unformed or missing limbs or dislocated hips.
The spine is examined for defects or deformities (such as spina bifida).