YOUR NEWBORN FROM HEAD TO TOE
Head and neck
The baby’s head is one-fourth of the size of the rest of his body and about half the size of an adult’s skull. The head could be misshapen temporarily from compression, and may have a swollen area on one or both sides. These swellings may grow larger in the first few days, then disappear completely in about a month. The baby will have two noticeable indentations on the top of his skull called the fontanels, or “soft spots.” The one nearest the front should be flat and firm, and it may pulse with the baby’s heartbeats. (Notify your baby’s pediatrician if it is raised or deeply sunken.) How long it takes for these indentations to disappear depends upon the baby, but most fontanels will vanish by 18 months of age. The baby’s skull will remain remarkably soft for the first few months, and it may appear to be lopsided or flat in the back, depending upon how the baby sleeps. The back of the baby’s neck contains special fat stores to help the baby keep warm.
A full-term newborn
Hair
Some babies are born with a full head of hair! But the color of a newborn baby’s hair is no indication of what color it will be later. It could turn out to be lighter or darker. The baby may also have fine, downy hair from the brows to the shoulders and down the back. This is called lanugo and is shed soon after birth.
Nose
The nose may be flattened or bruised from birth. He may sneeze and have a thin, white mucous discharge. The newborn has to breathe through his nose except when he cries. A special reflex in his throat will stop him from breathing under water. Some babies develop small, white bumps on their noses and cheeks called milia (see How to Read Your Baby’s Body Messages in this chapter).
Mouth and cheeks
Some babies take a few massive yawns after birth to force more oxygen into their lungs. The baby’s mouth, tongue, and jaw area are very well developed and prepared for nursing, but the baby may not salivate yet. The cheeks will be padded with extra fat around the sucking muscles. There are approximately 10,000 taste buds (more than adults have) located on the tongue, cheeks, and palate, in the back of the throat, and on the tonsils. The baby can tell the difference between sweet, sour, and bitter flavors and is most attracted to sweet flavors. The upper lip may have a blister in the center, and in rare cases, a baby may be born with one or two loose teeth in the front of the lower jaw, called milk teeth, that later fall out. There may also be white cysts (called Epstein’s pearls) along the midline of the palate that resemble small teeth; they usually disappear in a couple of weeks.
Ears
The baby’s ears may be soft, folded over, or floppy, but the cartilage will harden over the next few weeks. The baby’s hearing will be completely mature at birth, although he may not be able to interpret the meaning of sounds and language until later. He will react to voice tones and startle at loud sounds, which may also damage the hair cells deep inside the ears. The eustachian tubes that lead from the baby’s throat into the inner ear on each side are larger than those in children’s and adult’s ears. This causes the baby to be more vulnerable to inner-ear infections and to feel pain from the pressure changes in airplanes.
Eyes
Most newborns don’t have eyebrows. They are unable to produce tears for several weeks, and some may not do so for the first 4 to 5 months. The baby’s eyelids may be puffy, and the whites of the eyes may be bloodshot from labor pressures. Eyes will appear large in proportion to the head and the baby’s pupils will be more open than an adult’s as a result of immaturity, but these features also make the baby more appealing to his caregivers. The baby can only focus on objects about 8 to 10 inches from his face. Tests show that even newborns appear to be sensitive to different colors, especially high-contrast combinations like black on white. He has rudimentary depth perception. Eye color may be slate gray, dark blue, or brown, and will turn to the final color—a variation of brown, blue, or green—within 6 to 9 months. Your baby can blink, and his pupils will respond to light. He will have poor eye control, and his eyes may not work in unison for a few more months. A baby may appear cross-eyed from the folds between his eyes if he’s of Asian descent, or the eyes may temporarily cross because one eye has a stronger muscle than the other.
Arms and legs
The baby’s arms and legs are usually drawn up and flexed like a frog’s. Lying on his back, he may extend one arm out with his head facing that way. Arms and legs will jerk in and out during crying, and also make subtle, rapid movements to the rhythms of human speech.
Tip
The best time to trim your baby’s fingernails is when he’s asleep. Most nurses recommend using a soft emery board so you don’t have to worry about clipping skin on tiny fingers. Toenails may seem ingrown with the nail embedded in the skin, but that’s normal.
Hands and feet
Hands and feet may be temporarily blue after birth. Typically, the feet turn inward and are thought to be more sensitive to touch than his hands at this stage. Fingers are curled into tight fists. The baby’s grip is surprisingly strong, and he is almost able to support his entire weight when the fists are wrapped around an adult’s finger. The bed of the baby’s fingernails will be pink, and some babies are born with fingernails that need filing or clipping to keep them from scratching their cheeks. (Ask your caregiver for help if you are not sure how!) The soles of the feet are flat, and arches will not develop for a few more years.
Chest and stomach
The center of the baby’s chest may have a hard bump that is actually the bottom tip of the breastbone. It will gradually disappear. While an adult takes slow, steady breaths— about 12 to 20 per minute, a newborn breathes nearly once every second. He is a tummy breather, and breathing is often irregular—brief periods of nonbreathing followed by sudden, shuddering inhalations are normal. Within the first 7 days both boys and girls may have swollen breasts, and girl babies may have a slight discharge from their nipples, called witches’ milk. Newborns hiccup a lot, and the spasms of the baby’s chest are practice movements for the baby’s diaphragm. The baby’s stomach is about the size of a walnut, but it has the capacity to expand 4 to 5 times its size during feeding.
Skin and fat
The baby’s skin may appear thin, almost transparent, and it is more sensitive to touch than an adult’s. The skin will be blue immediately after birth and then turn red after the baby cries. It becomes mottled or splotchy once breathing gets underway. The baby’s skin is very sensitive to pain and will burn easily when exposed to sunlight or to water that might be a comfortable temperature for adults. Babies who arrive on time or later than expected will be pudgier and more “baby” faced, while babies who arrive early will seem wrinkled and more frail and thin-skinned. Some babies have birthmarks of different sizes and colors, and in most cases these will disappear over time. A few types of birthmarks are permanent, and some may need to be removed later. (For more on birthmarks, see in 6. Medical and Safety Guide.)
FLASH FACT: Heart Murmurs
About 1 in 3 babies is born with a heart murmur. Most murmurs are benign and resolve themselves within 24 hours after birth, while less than 1 percent of the murmurs signal heart disease.
Umbilical cord
It will be bluish white, coiled, coated in a jelly-like substance, and have two pulsing arteries and one vein. Its length averages about 20 inches, but it can be anywhere from 7 inches to an impressive 48 inches long. Clamping and cutting of the cord, which will be painless to the baby, should be delayed for about five minutes to allow the cord to stop pulsing so the baby can get a final burst of oxygen and nutrients from his mother’s body. The stump may be weepy after a week and bleed slightly, but it will dry up and turn dark before dropping off on its own in a week to 10 days.
Genitals
The baby’s genitals may look enlarged and swollen from absorbing the mother’s hormones. A girl baby may have vernix, a white creamy substance in the folds of her genitals. A boy will have small testicles in a large and swollen scrotum that is darker than the rest of his skin, and a girl baby may have a slight, bloody discharge. Both are the effects of the huge dose of maternal hormones the baby absorbs during labor. The swelling will go down sometime between days 7 and 14.
Boy-girl differences
Boy and girl babies really are different, and not just physically! On average, newborn girls weigh slightly less than boys do and are a little shorter, but a girl’s skeletal system is more mature. Girls average approximately 11 percent more brain cells at birth than boys do, and that gives them a distinct advantage later when it comes to learning language and communicating. The language part of the brain also matures faster in girls than in boys, and girls are more likely to talk sooner. Firstborns tend to talk slightly earlier than later-borns, too; perhaps because they get more coaching from their parents the first time around.
The retina inside your baby’s eyes is full of receptors for sex hormones, but boy’s’ retinas are thicker than girls’, and each sex has different concentrations of different types of cells. Even from birth, girl babies are better able to perceive differences in color and texture, and to prefer toys with patterns and textures. Boys are better at discerning the location, direction, and speed of moving objects and to prefer noisemaking toys. This may explain why even female baby monkeys prefer dolls (which have many different textures) and males are attracted to trucks and things that move.
While boys at two months of age are able to see greater distances than girls, girls are more able to distinguish individual faces and prefer examining the human face over anything else. A few months after that, girls are often more sociable and more inclined to “gurgle” at people and to recognize familiar faces than boys are.
From birth, girls are more sensitive to touch than boys, and one study found that the least sensitive girl baby was more touch-sensitive than the most sensitive boy was. Girls are also more sensitive to sound and are more easily agitated by noise. They prefer gentler sounds and are able to hear sounds at higher pitches than boys. For that reason, they prefer soft singing or the sound of a music box over loud or harsh sounds. One study in a Neonatal Intensive Care Unit (NICU) found that premature girl babies exposed to classical music could be sent home sooner, while the same music therapy had no effect on boys.
Boys are physically more vulnerable than girls during the first year (and more accident-prone later on). The mortality rate is 20 percent higher for boys than for girls. Sixty percent more boys die from sudden infant death syndrome (SIDS) than girls.
Surprisingly, babies learn gender differences early on. When your baby reaches five or six months of age, he or she will be able to distinguish between a male and a female face. By nine months, your baby will be able to pair a female face with a female voice. By 10 or 11 months, your baby will be able to match a male face with a male voice. And by 12 months, a girl who is shown a film involving people of both sexes will look longer at girls on the screen, while a boy will gaze longer at boys. Dads and moms are different, too, in how they relate to babies. The pupils of young women, whether they’ve had babies or not, dilate at the sight of babies. On the other hand, young men who aren’t fathers, whether they’re single or married, react negatively to baby images. The pupils of their eyes shrink as if to shut them out. While young women appear to have certain maternal instincts, young men need to have their fatherly feelings aroused by experiences with babies.
After their babies arrive, fathers tend to be more playful and provide more physical and social stimulation to their babies than moms, while mothers tend to be more rhythmic and soothing in their interactions. When dads take an active role in caring for their babies, they tend to become equally as responsive and sensitive to their babies’ cues as moms are. Babies adapt to the care of both their parents and, with enough touching, feeding, diapering, and playing, will attach deeply to both.
The first look
It’s not unusual for parents to feel strong surges of emotion when birth is finally over and the baby has arrived. You may weep for joy or simply feel overcome from having gone through such a powerful experience.
Almost every parent has the same impulse: to make eye contact with his or her newborn. There’s something so magical about linking eyes for the first time. “He sees me! He knows me!” And, in fact, he already recognizes your voice and your aroma.
Don’t be disappointed, though, if your newborn doesn’t bear any resemblance to those adorable babies you’ve seen in magazines and on television. If your baby comes early, you may joke that he resembles a little monkey more than a human baby. The media uses adorable images of babies that are at least six months old. It takes about that long to develop that fuzzy head of hair, those wide eyes, and those pudgy cheeks.
There’s no need to be concerned: Your baby is guaranteed to turn out to be equally as appealing as those front-page baby models; he just needs some time.
Making sense of baby senses
The deepest structures of your baby’s brain—those that control his breathing, protective reflexes, and heartbeat—are completely wired and fully functional at birth, as are the parts of his brain that regulate basic movements, muscle tone, and balance.
Hearing, taste, and smell are the most mature of your newborn’s sensory capacities. He’s already been exposed to lots of sounds in your body, including the intonations of your voice, the music you’ve listened to, and other familiar household noises, such as the dog barking.
Your baby’s tongue has over 10,000 taste buds, and he prefers sweet to sour flavors. In fact, he tasted a lot of different flavors before birth, depending upon what you ate. Your milk, sweat, and saliva contain some of the same, unique aromas that signal “you” and “home” to your baby.
Smell attracts your baby like a lightbulb does a moth. Unwashed babies who still have amniotic fluid on their hands are more successful in bringing their hands to their mouths for self-calming. If one of your breasts is washed at birth, but not the other, your baby will propel himself toward the unwashed breast that hasn’t had your scent removed.
Having lived for so long in semidarkness, your baby’s eyes will initially be extremely sensitive to light. His pupils will be widely dilated, and he’ll need time to adjust to bright lights and glare, especially since his blinking and eye-shutting skills are still weak. His eyes are able to focus the exact distance between his eyes and your face when nursing. By one week of age, he will have rudimentary depth perception, but he may not be able to coordinate both eyes for true depth perception until a few months later. He’s already pre-wired to prefer gazing at the pattern of the human face over all other patterns.
Even minutes after birth, he will be able to visually track slow-moving, colorful targets, but his head and neck movements are awkward and jerky, and usually his eyes won’t move separately from his head. Brainwave responses show that newborns are sensitive to different colors and are already able to perceive various colors and hues.
Your baby arrives with a highly advanced and intact hearing system that is perfectly adjusted for acquiring language—in fact, he’s already been listening to sounds for the past three months inside you. Some fetuses react to sudden sounds as early as 24 weeks of age—the sharper the sound, the stronger the baby’s reaction.
He can tell the difference between high and low pitches and loud and soft sounds, and he’ll react more strongly to high-pitched female voices than to the deeper tones that males make. Human babies naturally prefer the sound of the human voice over pure tones that mimic the same pitch as human sounds but aren’t real language. Later, when your baby starts imitating sounds, he’ll be much more likely to copy yours than to imitate inanimate noises.
Even though your baby can hear well, his ability to orient his head and body in the direction of sounds will take many months to perfect. Typically, he will react to a sudden sound by getting very still, or going into a full-fledged startle: blinking, catching his breath, and possibly starting to cry. Some babies may momentarily pause from nursing when there’s a loud sound.
How your baby’s brain grows
A human baby’s brain is truly remarkable. Before birth, it produced an average of 250,000 new cells every minute. During several key points in development, it generates over 50,000 brain cells per second. By 20 weeks, the brain has already had created 200 billion neurons. But 6 weeks later, only about 50 percent of these growing cells still survive. This overgrowing and cutting back of brain connections is the way nature ensures that your baby’s brain is customized to provide the exact mental equipment she requires to survive in her unique world. Even with all of those connections, your baby’s brain will double its weight by his first birthday, and continue to form some 1,000 trillion neural connections over the next two years.
Tip
If you’re wondering about the best brain food for your baby, it’s human milk. The baby’s body requires a lot of energy to grow and build a baby’s brain—twice the energy requirements of adults. Your milk is a transfer of living tissue, and it delivers the exact mix of proteins, fat, and sugars ideal for nurturing infant brain growth.
Your baby’s experiences and his built-in drive to communicate can affect the connections in his brain. Being deprived of a steady exposure to speech, holding, soothing, or rocking changes brain development. Babies deprived of exposure to language are likely to have delayed speech and difficulties mastering the intricacies of language later on, even though their physical equipment for speaking is perfect. Babies who are neglected and abandoned to lives in playpens and cribs may develop strange rocking and self-stimulation patterns, and if deprived of affectionate human contact may die, even though they are otherwise healthy and well-fed. A baby who is raised in the dark will likely to be robbed of his ability to see from the lack of brain stimulation that enables connections to form.
Baby see, baby do
Your baby has been born with “mirror” cells, a series of neurons resembling tiny, branching electrical wires scattered in various places in his brain. They provide him with a sophisticated form of instant replay when he observes the things you do. Within the next few days, if you move into focus—less than a foot from his face—he may try to imitate you as you stick out your tongue, purse your lips into a kiss shape, or make other facial gestures.
Your baby may imitate your expressions of mood, too. If you put on a happy face, your baby may widen his lips. For a sad expression, he may stick out his lower lip, and if you put on an exaggerated look of surprise, he may adopt a wide-open mouth and eyes. Babies of mothers suffering from depression, sadness, and overwhelming fatigue may respond by being less responsive themselves.
Baby movements mimic the rhythms of human language. Your baby’s body will actually dance in rhythm to the sounds of your speech, but his dance will be so rapid (measured in hundredths of a second) that many parents fail to perceive it. At the sound of a single word, your baby’s head may move slightly to one side, his elbow may move away from his side, a hip may shift positions, a shoulder on one side may rotate inward, and his big toe may curl in response to each word you say. But, he won’t do the body dance for made-up language or jibberish.
Later, your baby will not only babble with his mouth, but also with his hands! Babies born of deaf parents who aren’t exposed to human speech babble with their hands in different and more exaggerated ways than those who have hearing parents. Babies as young as six months of age can start to learn simple hand signs to show they’re hungry months before they are able to say words.