Your 1-Week-Old Baby’s Development

Major milestones and everyday tips for your baby at 1 week old

The first week of your baby’s life can be a special and overwhelming time. You may feel like you couldn’t imagine life without your little one, and also be amazed that your life could change so drastically overnight. Although your baby is only one week old, there is a lot that can happen in their growth and development during this time. 

1 week old baby development and milestones
Illustration by Josh Seong, Verywell

Your Growing Baby

At birth, a newborn baby is classified in one of three ways: small for gestational age (SGA), average for expected age, or large for gestational age (LGA). The exact height and weight of your baby will vary depending on if they were born full-term or premature, so at delivery, medical staff will evaluate your baby based on the averages for that age.

According to the American Academy of Pediatrics, the majority of babies born full-term weigh between 5.11 and 8.5 pounds, so anything between that range is considered a healthy average. For a full-term infant (born at or after 37 weeks of pregnancy), a low birth weight is classified as anything less than 5.8 pounds, while a high birth weight is anything over 8.8 pounds. Certain risk factors in the biological mother, such as smoking or gestational diabetes, can affect the baby’s weight as well. Keep in mind that your baby’s size at birth, in both length and weight, is not an accurate reflection of what they may be like as an adult.

Your baby will actually lose weight (the excess fluid from pregnancy and delivery) during the first few days of life. In fact, most babies will be considerably lighter by the time you are discharged from the hospital. This is normal, so there's no need to be alarmed. The AAP says most babies lose about one-tenth of their initial birth weight during the first five days of life, then slowly regain it over the next week. Typically, by day 10, your baby will be back up to the original birth weight. You can almost think of that first weight “re-gain” as your baby warming up for the real action. After they reach their birth weight again, 1-week-old babies gain weight very quickly—about 20-30 grams (or two-thirds of an ounce) every single day.

Your 1-week-old will also have their first doctor’s appointment—usually a few days after being discharged from the hospital. At the appointment, the doctor will measure your baby’s head circumference. Why? As it turns out, it’s a very important measurement that helps the doctor know what is happening with your baby’s brain growth. At 1-week-old, your baby’s skull is still growing and fusing together. On average, your 1-week old baby’s head circumference will be somewhere around 13.75 inches or 35 centimeters for baby girls, and slightly larger for baby boys.

Developmental Milestones

At 1-week-old, your baby is working on fine-tuning the skills needed to survive outside of the womb. The top priorities? Suckling, digesting, and setting up their immune system and digestion system with good flora to develop a separate microbiome from mom. Right now, your baby relies heavily on a sense of smell and sense of touch, so it’s important to have as much skin-to-skin contact as possible this week. You may also notice a lot of reflexes early on, such as appearing to startle or looking like they’re shivering—both are normal reflexes.

One key occurrence in newborns is their breathing pattern. At 1-week-old, your baby’s breathing will be irregular, with normal episodes of apnea (when they stop breathing altogether). This can be scary to witness when it first happens, but irregular breathing in newborns is actually normal, especially while sleeping. Of course, you should always monitor for a problem and follow safe sleep guidelines.

In your baby's first week, you can usually expect them to:

  • Have a spontaneous or almost reflexive smile, which can occur as early as your baby's first few days of life and should be present by 10 weeks old. This is different than the social smile that occurs in response to something, like when you talk or sing to your baby. Babies develop the social smile a little later when they are 1-2 months old.
  • Have equal movements of the arms and legs on both sides of the body. For example, 1-week-old babies shouldn't move one arm or one leg much more than the other, which could be a sign of injury or weakness.
  • Lift their head briefly when on their tummy. But remember, newborn babies have poor head control and need their head supported at all times.
  • Focus briefly on objects that are near the face and up to about 12 to 15 inches away, which is about the distance of a breastfeeding baby looking at their mother's face. Babies can also see simple, high-contrast patterns at this time, but their vision will quickly mature over the next few months. Your baby may also be able to respond to loud noises and look at and follow objects toward the midline of the face.

    When to Be Concerned

    Although 1-week-old babies will sleep a lot, if they won’t wake up for feedings or have any change in activity levels where they appear much more lethargic than usual, you will want to speak with your baby’s doctor. You should also be sure to call a doctor if you notice any additional symptoms, such as yellowing skin or a fever. Fevers in a 1-week-old can be a sign of a very serious infection, so don’t hesitate to take your baby into the doctor’s office or to the ER.

    A Day in the Life

    A 1-week-old, a baby will spend most of the day sleeping. In fact, during the first week of life, a typical newborn baby will sleep for 16-18 hours every 24 hours. However, because a baby’s body hasn’t started its own circadian rhythm with regular melatonin production, they don’t yet have the same sleep patterns an older child would, so a schedule can be pretty much non-existent. For this reason, it’s best to just go with the flow when it comes to your baby’s sleep and stay stress-free. Eventually, they'll develop a rhythm and you'll be able to rely on some type of schedule.

    Until then, your days and nights might feel a little mixed up during this first week. Your daily routine will consist of feeding the baby, sleeping, resting, diaper changing—and repeating. This first week, everything will be a bit of a challenge and that’s perfectly normal. Give yourself plenty of time to learn what it’s like to be a new parent! And if you haven't already had a baby shower or received the supplies you need for a newborn, make sure you pick up the basic equipment. Some of the essentials at this time include: 

    • Bouncer or another type of baby seat
    • Baby monitor to keep an eye on your little one when you're out of the room
    • Baby swing to help soothe and give them new scenery
    • Breastfeeding pillow, if you will be nursing, to help you stay comfortable and keep your baby in the correct position

    Baby Care Basics

    Here’s what you need to know to take care of a 1-week-old baby—from diapers to bathtime to helpful soothing techniques.

    Umbilical Cord Care

    Parents used to be told to frequently put alcohol on their baby's umbilical cord until it falls off, but that is no longer the recommended practice. Instead, the AAP recommends parents actually do nothing! Your baby’s umbilical cord will fall off on its own in about a week.

    Sponge Baths

    To avoid getting the umbilical cord too wet (and help it dry out), it's usually best to give your baby a sponge bath during this time. You can use a baby bath that doesn’t immerse the belly button area, or simply lay a towel on the floor and use a warm rag. Wash with soapy water first, followed by warm water to clean your baby’s skin. You might notice a lot of “cheesy” white substance. That’s vernix, which protected your baby’s skin in the womb and is completely normal. You can wipe it off if you want, but it will also absorb into your baby’s skin. Your baby’s skin might appear dry and cracked at this time, which is another after-effect of the womb and is not dangerous to your baby at all.

    Diaper Changes

    In the first few days of life, your 1-week-old baby will still be passing meconium (a mixture of skin cells, mucus, and other substances your baby ingested during delivery), which makes the bowel movements look dark, sticky, and almost tar-like in appearance. Those diaper changes can be challenging to clean, but they are normal.

    By the time your baby is 5-7 days old, your baby will need a lot of diaper changes and should be having six or more wet diapers and three to four loose yellow stools each day. Babies who are exclusively breastfed will have stool that can vary in color, from bright yellow to greenish.

    During this week, your baby's stools will change from the large, black, tarry meconium, to green/yellow transitional stools, to the more regular yellow bowel movements of an older baby.

    Nail Trimming

    Trimming your baby's fingernails when they seem long is important and can prevent accidental scratching of the face, or more seriously, the eye. You can use a baby nail clipper or a nail file to give them a trim. You may need an extra set of hands, or you can do it while your baby is sleeping or eating to avoid extra movement.

    Burping

    You should usually burp your baby after each feeding to prevent gas and fussiness. If your baby spits up a lot if you burp them during feeding, they may do better if you wait until the end. Breastfed babies may not need to be burped as frequently as babies fed from a bottle since they don’t swallow as much air during feeding. But every baby is different, so take special note of how your baby acts after eating. If they seem fussy or uncomfortable right away, it may be time for a burp.

    If you're having trouble getting your baby to burp, try a new holding position. For example, try burping your baby lying against your shoulder. If you don't get a burp, switch to a more upright position and burp while they're sitting up.

    Feeding & Nutrition

    For a 1-week-old baby, you may still be choosing your preferred feeding technique, and it may change as your baby grows. You can choose to feed your baby breast milk from the breast, expressed breast milk from a bottle, formula from a bottle, or a mixture of breast milk and formula. For the first 24 hours after your baby is born, you might notice they seem especially sleepy and uninterested in eating. This can be normal as babies recover after delivery (they went through a lot, too), so just check that your baby is getting enough to eat by how many wet and dirty diapers they have.

    Breast Milk

    Breast milk does provide optimum nutrition for a baby, but every family situation is different, so there are a lot of factors that go into deciding what's best for you and your baby. Remember, breastfeeding doesn’t have to be “all or nothing,” either. If you are interested in providing your baby with breast milk, there are many options you can choose—from feeding the baby from your breast full-time, feeding from the breast part-time, doing a mixture of pumped breast milk and formula, or utilizing donor breast milk if it’s available.

    If you're interested in supplying breast milk yourself, it's very important to try to get your breast milk supply established during this first week. You can get your supply going by putting your baby to the breast frequently to initiate breast milk production, by nursing on demand, and by getting plenty of fluids and rest. Breast milk typically begins to comes in around day four or five and is generally established by day 11.

    If you need help breastfeeding, don’t hesitate to call a lactation consultant, nurse, or doctor while you are in the hospital or after you've been discharged so you can get your supply established and correct any issues right away. Breastfeeding might be uncomfortable in the beginning, especially as your milk comes in and your breasts fill up, but it should never cause excruciating pain or bleeding. If you develop a fever or have any reddened, hardened spots in your breast, it could signal an infection, so call your doctor right away.

    You may also want to consider these helpful breastfeeding tips:

    • Plan to breastfeed your newborn baby 8-12 times a day during the first few weeks.
    • Try to make sure your infant nurses from both breasts for each feeding and fully empties each breast, if possible. Not only will this help encourage your supply, it will also ensure your baby is getting their full nutrients. There are different types of milk released during the beginning of the feed, the middle, and the end. The end especially contains lots of healthy fats your baby needs to grow.
    • Get help if you begin to have problems, including a poor latch, engorgement, sore nipples, or to improve your breast milk supply. This help might come from other moms who have breastfed their children, a pediatrician who is supportive of breastfeeding, and/or a lactation consultant.
    • Avoid formula supplements as you establish your supply, unless your pediatrician thinks they are medically necessary.
    • Most experts recommend you don't introduce bottles or pacifiers until breastfeeding is well established.

    Baby Formula

    If you're not breastfeeding, your 1-week-old baby will likely be drinking a milk-based, iron-fortified baby formula. Your baby will probably only drink about one to two ounces at a time, every two to three hours, during the first few days. This amount will slowly increase to two to four ounces by the end of the first week.

    Feeding Schedule

    Especially during the first few weeks, it's usually best to feed your baby on demand every 1.5-3 hours and not on a strict schedule. More tips for feeding your 1-week-old include:

    • Learn your baby's hunger cues and go with them! Don't wait until your baby is crying to start to feed them.
    • Ensure that you're feeding at least 8-12 times in a 24-hour period.
    • If your baby is not waking on their own at the 3-hour mark to feed, it's time to step in and help them along.
    • If your baby is too sleepy for feedings, you can help wake them up by stripping them down to a diaper to keep them awake during feedings and make sure they're sucking properly.

    Sleep

    As introduced above, your 1-week-old baby will sleep a lot—but not necessarily during the night when you'd like them to. Although you might be able to try sleep training later, your 1-week-old baby is still learning to adjust to life outside of the womb, so this week is all about going with the flow. Sleep when you can and let your little one sleep when they are sleepy. Again, be sure to follow safe sleep guidelines set by the AAP, which include the following:

    • No co-sleeping of any kind
    • Room-sharing for the first six months of your baby’s life with a bassinet, cradle, or crib that is near the mother's bed, but not in the bed
    • Always placing your baby to sleep on their back (never on the side or stomach) on a firm sleep surface, such as a firm crib mattress covered by a well-fitted sheet
    • There should be nothing at all in the crib, including soft objects like pillows and toys or loose bedding. The AAP also recommends not using bumpers of any kind, including the “breathable” versions, as they have not been proven to be safe for sleep. 

    If you're having trouble getting your baby to sleep in a crib, consider using a bassinet or cradle instead. A full-size crib is sometimes too big for a newborn. Swaddling often helps babies get to sleep, stay asleep, and get comforted quickly, especially when they are newborns.

    To help everyone in your family get enough sleep, parents may try to take turns caring for their baby at night, take naps during the day when their baby is sleeping, and get help from family and friends when possible. Your partner can help at night by changing the baby's diaper, setting your baby up for the feeding, and putting them back to bed.

    Health & Safety

    Ideally, your home and environment will be well baby-proofed before your baby is born. In fact, it is a policy in most hospitals that you show you have a properly installed car seat before you are allowed to bring your baby home. In addition to a rear-facing car seat, you can make your home safer for your baby in these ways:

    • Make sure your baby’s crib is safe. Always buy a new crib to ensure it is up-to-date with safety recommendations. Place the crib away from windows, cords, heaters, and furniture that could fall.
    • Don’t use hand-me-down equipment, such as car seats, strollers, and cribs.
    • If you do have any used products, call the manufacturer or the Consumer Product Safety Commission for an up-to-date list of recalled products.
    • Set the temperature of your hot water heater to 120 degrees Fahrenheit to prevent scalding burns.
    • Install smoke and carbon monoxide detectors and use flame-retardant bedtime clothing.
    • Make your home smoke-free so your baby isn't exposed to secondhand smoke. Simply smoking outside is not enough to reduce your baby's risk of SIDS, ear infections, asthma, and other conditions.
    • Review your home's risk for causing lead poisoning, especially if it was built before 1978.

    Immunizations

    At 1-week-old, your baby will receive the Hepatitis B vaccine (the first vaccination), which is sometimes given right in the hospital before you are discharged. This vaccine is given so early because it can help protect a newborn from getting infected from a family member who may not know they are infected. The Hepatitis B vaccine is safe for newborns to receive.

    Common Concerns

    One of the most common concerns for parents of a 1-week-old baby is jaundice. Jaundice is a condition that can occur in newborn babies when they have a high level of bilirubin. As a 1-week-old baby is still adjusting to life outside of the womb, they may have a delay in clearing some of the extra red blood cells from pregnancy and delivery. As those red blood cells break down, they release bilirubin, which is normally taken care of by the liver and eliminated through bowel movements. If the baby can’t quite keep up, however, the bilirubin can build up, leading to that classic sign of “yellowed” skin and even eyes.

    If your baby is diagnosed with jaundice, it is very important to continue to feed your baby to help clear the bilirubin from the system and to check in frequently with your pediatrician for the first two weeks of your baby's life. They will guide you as to when the baby needs to be seen.

    When to Call Your Pediatrician

    • If your baby is not feeding 8-12 times in a 24-hour period
    • If your baby is not wetting or having bowel movements. By day two, you should see at least two wet diapers and three black tarry stools (meconium). Day three, at least three wet diapers and three greenish-brown bowel movements. Day four, at least six wet diapers and three mustard-yellow bowel movements. Please keep in mind that these guidelines are per day, not the total since birth.
    • If your baby is either too sleepy or too cranky
    • If the color of your baby's skin or eyes is getting more yellow (bordering on orange), or if the color is below the belly button level

    Must Knows

    This first week is an enormous adjustment for new parents, so try to keep these tips in mind:

    • Take it one step at a time. You have a whole lifetime to handle this parenting thing—you don’t have to learn it all in the first few days!
    • Focus on what is most important. Right now, the most important thing that both you and your baby need is rest and recovery. Get as much rest as possible. We won’t tell you to sleep when the baby sleeps, because that’s tired advice, but we do recommend you sleep whenever you get the chance.
    • Nourish your body. If you gave birth either vaginally or through a C-section, your body has been through a tremendous physical feat. It needs time to rest and recover, and it’s important to provide it with good nutrition. Drink plenty of water and focus on lots of healthy fats, carbohydrates, and proteins that will help your body heal. If you have welcomed a baby into your home in other ways, it’s still important to keep your body well-nourished through all of the nights of sleep deprivation.
    • Soak it in. There is no other time in your life like the first week with your baby, so try to enjoy every single moment of those newborn snuggles and smells—except maybe those meconium diapers.
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