8-Week-Old Baby
Wow, eight weeks have gone by! There has been so much physical, emotional and mental growth in this time—for you and baby both. Your child has gone from a sleepy newborn to an alert infant, leading to more interaction and connection with the special people in their lives. Baby development at 8 weeks old seems to speed forward as your child gets stronger and more aware. Here’s what to expect from 8-week-old baby development.
Growth
At this week’s pediatrician visit, your doctor will be able to confirm that baby is growing appropriately. According to the World Health Organization (WHO), the average weight of an 8-week-old baby is 11 pounds for girls and 11.9 pounds for boys, while average height is 22.3 inches for girls and 22.8 inches for boys. But as long as your child is following their own growth curve, it’s totally normal and healthy to fall somewhat below or above these averages. Premature babies in particular are often on the smaller side.
In the month ahead, baby will likely grow about 1 to 1.5 inches in length and up to 2 pounds in weight, but these are just averages rather than strict guidelines.
Emerging skills
Baby at 8 weeks old has been working hard, as they’ve learned to adjust to life outside the womb. At this age they should be able to lift their head for longer periods during tummy time. They can also track objects with their eyes.
A 2-month-old baby is probably exploring with their hands more as they examine them, open and close fists and self-soothe by sucking on fingers. While they aren’t grabbing things independently yet, if you hand your 8-week-old baby a rattle, they can probably hold on to it for a bit as those fingers close around it. You may notice that their movements are becoming smoother and less jerky.
If your 8-week-old baby isn’t tracking with their eyes, lifting their head, making eye contact, smiling or responding to loud noises, it’s worth mentioning to the pediatrician at their appointment this week. It could be nothing, but it’s worth flagging just in case.
Feeding
As baby grows, so too will their appetite. But how much should an 8-week-old baby eat? Around 4 to 5 ounces every three to four hours is typical. A good way to tell that baby is getting enough is to make sure they have at least five wet diapers a day. On the other hand, if they spit up a lot or seem to have gas pains, they may be eating too much, though babies are usually pretty good at consuming only what they need. An 8-week-old baby feeding amount shouldn’t exceed 32 ounces of formula in a 24-hour period.
Sleep
A baby at 8 weeks old is still establishing their sleep cycles, but around now is when they develop a rhythm of cortisol, a steroid hormone secreted by the adrenal gland that’s a crucial component of the body’s circadian rhythm. By around 3 to 4 months, a baby’s circadian rhythm is fully established, which is a major step toward sleeping through the night. All this is to say that you shouldn’t expect a full night’s sleep just yet, but that milestone is hopefully within sight. There will be ups and downs, and every baby is wired differently.
There’s always a chance that baby will surprise you and conk out for as much as eight hours overnight, but it’s more likely that they’ll have at least one good chunk of four to five hours. Make sure they eat enough during the day so they’re less hungry at night. If your 8-week-old baby is sleeping more than usual, they may be growing. Keep an eye on them—when in doubt, call your pediatrician.
Common ailments
Fussiness following vaccinations
This isn’t an ailment per se, but many parents worry about how their baby will react to the vaccinations they’ll receive at their two-month well visit. If your pediatrician follows the CDC vaccination schedule, then get ready for two to three shots and an oral vaccine. Baby will likely get the pneumococcal, DTaP, Hib, polio and rotavirus vaccines, as well as the second hepatitis B vaccine if they didn't get it at the one-month visit.
Serious adverse reactions are incredibly rare. One study found that only 19 percent of vaccinated children experienced even non-serious reactions such as fussiness and swelling or redness at the site of injection. Babies used to routinely get acetaminophen (Tylenol) before shots to lower the chances of developing a fever, but research suggests this may actually decrease the effectiveness of the vaccine. The advice now is to give Tylenol only as needed. If baby is fussy or has trouble sleeping, it should only last a day or two. If they have a rectal temperature of 100.4 or above, however, you should call your pediatrician who will advise on next steps.
My 8-week-old baby isn’t smiling. Should I worry?
There’s nothing better than true baby smiles, but if your little one is still only giving you gas smirks, there’s no cause for concern. There’s a developmental range, and babies can begin smiling anywhere between 6 and 12 weeks. If you’re concerned, you can always bring it up at their well visit this week.
What medicine can I give to my 8-week-old baby?
If your 8-week-old baby is fussy or seems to be in discomfort, it’s natural to want to make them feel better. Because infants don’t yet have a well-developed internal thermostat, it’s important to get in touch with their doctor right away if they have a rectal temperature of 100.4 or higher, as it could be a sign of something that needs attention. For this reason, the AAP advises parents to check with their pediatrician before giving a baby under 12 weeks acetaminophen (like Tylenol). Be aware that babies shouldn’t be given ibuprofen (Advil or Motrin) before 6 months of age because its safety hasn’t been established.
What to do if baby only sleeps when held
Holding a sleeping baby is oh so sweet, but if it gets to the point that baby won’t sleep unless held, it can start to get frustrating. While an 8-week-old baby is still in their so-called fourth trimester, you can still work toward developing good sleep habits. Work on independent sleep gradually, whether it’s at nap or bedtime. Begin your sleepytime routine when they’re starting to get tired but before they’re overtired; at this age, babies shouldn’t be awake for more than 90 minutes or so at a time, so use that as a guideline. You can move into a darkened room, rock them a bit while singing or read a book with them on your lap, and then lay them down in their crib or bassinet. You can hold their hand or gently rub their back. If they start to really cry, you can try picking them up, comforting them and putting them back down. With some practice, baby will learn that their bed is a safe, comfortable space and that their grown-up will always come back.
Growth charts
You’ve probably heard your pediatrician talk about the baby growth chart, especially at this week’s well visit. The chart is used by pediatricians to track baby’s physical development at every checkup, so they can keep tabs on baby’s weight, length and head circumference. The CDC and WHO growth charts show average growth for baby boys and girls by age, but what your pediatrician will care most about is plotting your child’s unique growth curve, and assessing whether their length and weight gains stick more or less to that pattern. After all, normal growth is whatever is normal for your little one. You may be tempted to track baby’s development at home, but experts say you really don’t have to. Doctors will whip out the measuring tape and place baby on a scale at every checkup—meaning they’re on top of it, and it’s one less thing for you to worry about.
- Take your vitamins. You probably spent months taking prenatal vitamins, but just because you’ve had a baby doesn’t mean it’s time to stop. Most providers recommend continuing with prenatal vitamins or switching to postnatal vitamins for at least the first three months following childbirth. This is especially important for breastfeeding parents, because it helps replenish your nutrients and also passes on those benefits to baby. Besides a multivitamin, additional supplements like DHA (found in fish oil) and vitamin B12 can also aid in baby’s brain development.
- Trust your gut. Sure, there are a million parenting experts out there, but nobody knows your little one better than you do. While we don’t recommend disregarding evidence-based medical advice, there are times when a parent can just feel that something is up with their baby, or that a particular bit of parenting advice isn’t helpful for their child. Part of becoming a more experienced parent is learning when to trust your gut.
- Baby swing. Baby still probably wants to be held all the time, but they’re at an age now where they can get bored. Since at some point you’ll need your hands freed up, having a safe, enjoyable place to put baby for a few minutes is key. Enter: the baby swing. These soothing, rocking seats come with every level of bells and whistles and can also help combat witching hour fussiness. Just read all the instructions for safe use, and don’t let baby sleep in the swing or spend too much time in one—they still need plenty of opportunity to move their limbs.
- Travel crib. If you’re planning on hitting the road with baby, a travel crib is a must-have. These nifty products fold up, mattress and all, so you can take them with you, whether you’re visiting Grandma or staying in a rental. Hotels often say they have cribs available, but it’s not a given, and they can be old and well-worn, so having your own option may give you peace of mind.
Up until now, baby’s eyes weren’t yet coordinated and strong enough to work well together all the time. But that changes around 2 months, and they should now be able to follow an object with their eyes. If you’re wondering what to do with your 8-week-old baby, you can help them strengthen their visual coordination in playful ways, like putting on a puppet show. All you need is a simple hand puppet—even a sock works. Make some funny voices or sing some songs while slowly moving the puppet around in front of baby when they’re alert and content. Watch as their eyes follow the puppet; you’ll hopefully get a few smiles while you’re at it too.
Please note: The Bump and the materials and information it contains are not intended to, and do not constitute, medical or other health advice or diagnosis and should not be used as such. You should always consult with a qualified physician or health professional about your specific circumstances.
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