Your Baby's Development at Three Weeks Old

You would think that your baby's third week would be easy. After all, she is likely feeding well now, is used to being home, and mom has likely begun to recover well from having a baby.

This can be a transition week, though, from having a baby that is calm, quiet, and feeding well, to one that is more active, harder to comfort, and often crying.

During your baby's third week, it can be helpful to:

  • learn the difference between medical issues that can cause fussiness, including reflux and food intolerances, colic, and a baby who simply has a "spirited" temperament.
  • figure out what works best to comfort your baby when she is crying.
  • continue to feed your baby on-demand and work towards staying on a regular routine or schedule based on your baby's needs and demands.
  • feed your baby before she gets over-hungry (remember that crying is often a late sign of being hungry).
  • put your baby to sleep before she gets overtired.

Getting Help

And most importantly, get help, to help take care of your newborn baby. Too often, people don't think to call or visit after you have a new baby because they think you are busy bonding with your baby or that other people are helping you. You may need to call for help if you need it.

Remember that you don't have to do everything yourself.

Helping a new mom doesn't mean that they just have to help hold the baby, though, which seems to be what most people like to do. Don't be afraid to ask people who offer to help that they do other household chores, take care of your other kids, or run errands for you, so that you can continue to spend time with your new baby.


Supplementing with a Bottle

If you were supplementing your baby with a bottle, but now have a good supply of breastmilk and your baby is latching on well, talk to your pediatrician to see if you can wean your baby from the supplemental bottles.

Remember that you don't necessarily need to give your baby a bottle, but some breastfeeding moms do around three weeks if they suspect that they will need to later on anyway. This is OK as long as you baby is breastfeeding well. If he isn't, a bottle now may still lead to some nipple confusion.


Many experts believe that using a pacifier may interfere with breastfeeding and they are associated with early weaning. On the other hand, they are thought to help reduce a baby's risk of SIDS. So should you let your breastfeeding baby use a pacifier?

Probably, but to avoid any breastfeeding problems, wait until you baby is at least one month old. Then only offer the pacifier at sleep times and don't reinsert it once your baby falls asleep.

Growth Spurts

A growth spurt can often cause confusion for a breastfeeding mother.

Whether it is at three weeks or three months, a growth spurt can throw off a feeding schedule that had been fairly regular. For example, a baby that is breastfeeding every three hours may want to feed every hour and a half or two hours during a growth spurt. The problem is that some mothers misinterpret this increased demand as a sign that they need to start supplementing with baby formula. Instead, if they simply try to keep up with the increased demand, their breast milk supply should increase to meet their baby's demand and they will quickly get back to their usual schedule.

Fussy Babies

Parents, even first-time parents, expect their new babies to cry sometimes.

Most parents aren't prepared for the fact that they may have to cope with a crying baby for two or three hours a day, though!

Fortunately, most of that crying is not continuous.

Your Crying Baby

Why do babies cry?

One of the main reasons is that it is really their only way to communicate with us. So they cry when they are hungry, cold, tired, or need to be changed. One way to help your crying baby could be to anticipate these needs and quickly respond to them. Remember that you really can't spoil your newborn baby, so don't worry about picking him up right away or that you are holding him too much.

More frustrating though is when your baby cries for no reason at all.

Crying Too Much

How do you know if your baby is crying too much?

The first step is to simply trust your instincts and see your pediatrician if you think your baby is crying too much. Even if your crying baby is totally normal, some reassurance will help you to feel better.

Otherwise, look for some of these signs and symptoms that might indicate that your baby's crying might be caused by a 'real' problem, including:

  • having a fever, cough, and/or runny nose
  • crying during or right after feedings
  • really crying all of the time and for more than three hours a day
  • having reflux or spitting up a lot
  • having gas, diarrhea, or foul-smelling stools
  • losing weight or not gaining weight normally
  • having bloody stools

These could be symptoms of an infection, reflux, or formula allergy. Even breastfeeding babies can have food allergies if they have a problem with something mom is eating and drinking that is going into her breast milk like cow's milk.



No one really knows what causes colic. Maybe that is because any time a baby cries it is often blamed on colic.

Although the cause isn't exactly known, some facts about colic that are known include that:

  • colic often begins when a baby is three weeks old, peaks when he is six weeks old ​and is typically gone by about three months
  • babies with colic often cry for about two or three hours a day, at about the same time each day, often in the early evening
  • colic doesn't usually cause other symptoms and babies with colic typically feed and gain weight well
  • there is no known cure or medical treatment for colic, although parents often try homeopathic colic tablets and gripe water, which are popular over-the-counter colic treatments

Trying to comfort your baby by swaddling, rocking, or singing to your baby, etc., is often the best treatment for a crying baby with colic.

Although often blamed on digestive problems or formula allergies, colic is likely a normal developmental stage that some newborns go through. Some experts describe it as a baby's way of blowing off steam.

Skin Rashes

Unfortunately, babies often don't have very clear skin.

Baby Acne

Neonatal or baby acne is a common problem that begins after a baby is a few weeks old. It is thought to be triggered by maternal hormones that a baby gets even before she is born.

Infants with baby acne typically get whiteheads, blackheads, and pustules on their nose, scalp, cheeks, and forehead. Their skin may also appear red and rough. Although its appearance is often distressing to new parents, no treatment is usually required. In fact, baby acne typically goes away on its own in a few weeks or months. 

Heat Rash

As the name implies, heat rash is triggered in some babies when they become overheated, either because they are overdressed or because it is simply too hot outside. As they become hot and sweat, their sweat ducts become blocked and rupture.

Prickly heat, which is also known as miliaria rubra, is the most common type of heat rash. In this form of heat rash, the sweat duct becomes red and inflamed and look like small bumps with a red halo around them. They can be found grouped together under a child's clothing and inside the folds of his skin, such as his neck, armpits, and groin.

Miliaria crystallina is another type of heat rash, but the skin doesn't get inflamed, leading to the classic appearance of small clear vesicles, without any redness or other symptoms. 

Cradle Cap

Cradle cap, a common rash on a baby's head, is usually easy to recognize, with symptoms that can include a scalp rash that:

  • is dry and flaky
  • has thick, greasy, yellow or brown scales
  • has red patches with crust
  • is sometimes itchy

For mild cradle cap, time is often the best treatment, as many children get better on their own by the time they are about 1 year old.

Week Three Care Tips

Umbilical Cord Care

If your baby's umbilical cord hasn't fallen off yet, you are likely beginning to get tired of basic umbilical cord care. Stick with it though and your cord should come off either this week or next week.

Taking a Rectal Temperature

With the advent of digital thermometers, taking your baby's temperature is a lot easier than it used to be. If you buy a digital baby rectal thermometer, it can be even easier. These thermometers are mercury-free, specifically designed for use in newborns and infants, give a reading in 5 to 10 seconds, and include a short, flexible tip, so you don't have to worry about inserting the thermometer too far.

To take a rectal temperature, first make sure that you are actually using a rectal thermometer. Next, turn the thermometer on and lubricate the tip with some petroleum jelly or another water-soluble lubricant. Last, gently insert the tip about 1/2 inch into your baby's rectum and wait for the thermometer to beep. Then read your baby's temperature.

Be sure to wash the thermometer with soap and water so that it is clean the next time you need it.

If your baby has a fever (temp at or above 100.4 F) using a different method, such as using a tympanic thermometer (in your baby's ear) or checking under his arm, it is usually a good idea to confirm that he really has a fever by taking a rectal temperature. Many experts think that a rectal temperature is the most accurate way to take a temperature in the first few months of a baby's life.

Also, instead of adding or subtracting a degree when taking your baby's temperature, which is common practice when taking oral and underarm temperatures, it is usually best to just tell your pediatrician the exact temperature and the method you used to take it.

Crying Without Tears

If your infant is crying without tears, It is probably normal, especially if she has no other symptoms.

Newborns start making tears when they are about two weeks old, but often it is just enough to keep their eyes moist. However, it is not enough to make real tears that you can see when they cry. Infants often don't develop real tears that you can see until they are much older and about seven or eight months old.

If your baby truly wasn't making any tears, then she would likely have other symptoms, including that her eyes would be very red, dry, and irritated.

Week Three Medical Issues


Unlike older children, it can be difficult to tell when a newborn is seriously ill.

That is why doctors routinely do a septic work-up on infants who are under two or three months old when they have a rectal temperature that is at or above 100.4 F.

Be sure to call your doctor or seek medical attention if your baby has a fever.

Umbilical Cord Issues

The biggest issue with a baby's umbilical cord is that it sometimes doesn't fall off as quickly as a parent would like. Keep in mind that your baby's umbilical cord may not fall off until your baby is three or four weeks old. See your pediatrician if it is staying on longer than that or if it is showing any signs of infection. An infected umbilical cord may have a foul-smelling discharge and/or the skin around the cord may be red and tender.

Blocked Tear Duct

As your baby starts to make tears when he is about two weeks old, if he has a blocked tear duct, you may notice a lot of extra tearing. The tear duct normally drains tears from the inner corner of your baby's eye into his nose. When blocked, the tears pool in his eye and drain onto his cheek. Or the eye becomes crusted and matted when the tear duct gets infected.

Fortunately, most cases of blocked tear ducts go away on their own. You may have to treat your child with nasolacrimal massage (in which you massage the inside corner of your child's nose two to three times a day), cleaning any discharge or matter in the eyes with a warm washcloth, and occasional topical antibiotics, until it does, though.

Breastmilk Jaundice

Although jaundice usually clears by your baby's second week, breastfeeding babies with breast milk jaundice may continue to be mildly jaundiced until they are 2 to 12 weeks old.