Medically Reviewed by: Dr. Deborah Lee
Your 4-week-old baby has been in your life for almost one month and by now, you’ve probably begun to notice your baby reaching development milestones already as you start to get the hang of this whole parenting business.
If you still have a lot of questions, don't worry – it's completely normal – we're here to tell you what you can expect from their week-by-week development when your baby is in their fourth week.
Development milestones for a 4-week-old baby
According to Dr. Deborah Lee, they say: "By 4 weeks, your baby should have regained any lost birth weight and be putting on weight around 7 ounces (1770 g) per week. At this stage, your baby should be feeding well. A breastfed baby should be put to the breast 8-12 times a day. A bottle-fed baby should be taking 20-30 ounces in 6-8 feeds a day. A 4-week-old baby will need 2-3 night feeds, says Dr. Lee.
Your baby will be sleeping for 12 or more hours a day, and waking every 2 to 4 hours. When they are awake, you will notice they seem more alert, make more eye contact and follow an object with their eyes. You should see that they turn their head in the direction of the sound.
This is an exciting time for parents as this is when their baby starts to show signs of social development. You can see they will start to recognise their parent’s face, and your baby’s face will light up with a smile. Your baby is also making cooing, gurgling and aahing noises, and putting their fingers in their mouth and sucking them, says Dr. Lee.
Sleep patterns and routine for 4 week 4-week-old baby
A 4-week-old baby will typically sleep for 8-9 hours at night and 7 hours during the daytime, punctuated by feeds. Most babies only start sleeping through the night from 3 to 6 months of age. As they grow, they will gradually sleep more at night and have less sleep during the day.
A 4-week-old baby has a 30-90 minute wake window. The wake window tends to be shorter in the morning and longer as the day passes, says Dr. Lee.
Babies don't automatically know how to go to sleep by themselves, so they need to learn to do this. Much as it feels natural to want to rock your baby to sleep, if this always happens, they will not be able to be put down to go to sleep by themselves.
Tips to help your baby sleep include
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Keep the lights dim and the room quiet so the baby is not overstimulated.
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A new baby may like to hear white noise, which is thought to be reminiscent of being in the womb. White noise is a particular type of sound, such as the gentle background whirring of a vacuum cleaner or a washing machine, that can help a baby drift off. Some parents like to use a white noise machine, which should be placed outside the cot and only at a low volume.
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Make sure your baby isn’t too hot. Babies are not good at regulating their own body temperature and are at risk of overheating. Don't let them wear nightwear that is too thick, and keep the room temperature cool in the bedroom. The room temperature should be 16 - 20 °c.
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Most often, you will be putting your baby to bed after feeding and changing, which makes them feel tired and ready for sleep. Put them down when they are drowsy but still awake so they can learn to go off to sleep on their own. Babies who can do this sleep more soundly in later life, says Dr. Lee.
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If they cry, pat them on the back and soothe them for a few minutes. You can leave the room for a few minutes and go back. If this isn't working, pick them up, cuddle them for a few minutes, then repeat the pattern. The 'cry it out method' is not recommended for newborn (4-week-old babies) so don't leave them to cry for more than 10 minutes at most.
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At other times, look out for signs your baby is tired and ready for sleep. They may start yawning, stare into space, or become very irritable and be grizzly and crying. They may start rubbing their eyes or pulling their ears. It’s important to recognise signs of tiredness and put the baby to bed at this stage and not let them get over tired, as this makes getting to sleep even harder, says Dr. Lee.
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Create a routine for your baby and stick to it. Babies like consistency. If you know when their wake time and nap times will be and work around this, you are more likely to get good results. From an early age, start a bedtime routine, with a warm bath, a feed and some cuddle time with a story before putting your baby to bed for the night. As they grow, they will recognise that this is what happens at nighttime, and they need to go to bed and stay there! But it doesn’t happen instantaneously, you need to work at it, says Dr. Lee.
Sensory & cognitive development for a 4-week-old baby
Sight – At 4 weeks, a baby's vision is developing. At birth, a baby has small pupils which restrict the amount of light falling on the retina, but by 4 weeks of age, their pupils will have dilated. They can now see colours and shapes. From 4 weeks that are able to focus on an object that is around 18 inches in front of their face.
You can help your baby’s eyesight by placing a mobile over the cot. Newborns respond best to black and white images. Play with your baby, raising their arm or legs and talking to them. Bouncing them on your knee while looking into their face. Show them picture books, initially fabric books, with bright colours and images. Playing games and talking to your baby encourages them to pay attention and focus on what is in front of them. This is also crucial for their social development, says Dr. Lee.
Hearing – Your baby can hear from birth. In fact, they can hear in the womb from 16 weeks of conception! You will notice a newborn startle when they hear a loud noise. However, their hearing is still immature and is continually developing. They respond best to high-pitched and exaggerated sounds. You will notice that your baby at 4 weeks can turn their head towards a sound, for example, the sound of your voice.
You can help your baby’s hearing by talking regularly to your baby, so they get used to the sound of your voice. As they grow, they mimic sounds, and this is very important for their speech development. Also, play with your baby with rattles and musical toys, which stimulate their hearing and sing to your baby.
Make sure your baby is not exposed to loud noise, which could damage their hearing, says Dr. Lee.
Your baby will have a hearing test in the first few weeks of life, done in the hospital before discharge or by your health visitor at home when they are a few weeks old. It should be done before 4-5 weeks of age. Make sure your baby has been tested.
Touch – By 4 weeks, a baby's touch is well developed. All touch is vital for their growth and further development. Skin-to-skin touch is crucial, such as cuddling them naked or when just in their nappy - when lifting, changing and bathing them. This helps establish a loving bond between you both., says Dr. Lee.
A small baby will initially touch objects by reaching out with their fists, but gradually their fingers uncurl, and they can touch objects. Touch is vital for developing hand-eye coordination. You can play with your baby by placing your finger in their palm and feeling them curl their finger around yours.
Many baby toys consist of different fabrics with different textures. It's important to encourage your baby to feel a wide variety of different things to encourage their motor and social development.
Cognition – Neuroscientists believe a newborn baby is aware of their own body. Although they are not as conscious (wide awake) as adults, they still have enough consciousness to know they are present in the world and to notice a lot about what is going on around them. Research has shown that newborn babies can distinguish their own cry from that of other babies, says Dr. Lee.
Small babies also develop facial recognition early on. They can distinguish one face from another within 90 seconds of staring! They are learning and developing continuously. They prefer happy faces to sad ones.
Everything you do with your baby, when you talk and sing to them, feed them, play with them, and introduce them to objects and sounds, is vital for their cognitive, emotional and social development. Failing to do this with a baby puts them at risk of poor growth and developmental and cognitive delay, says Dr. Lee.
Feeding and nutrition for a 4-week-old baby
Dr. Lee also says that: "By 4 weeks, your baby should have regained any lost birth weight and be putting on weight around 7 ounces (1770 g) per week. At this stage, your baby should be feeding well. A breastfed baby should be put to the breast 8-12 times a day. A bottle-fed baby should be taking 20-30 ounces in 6-8 feeds a day. A 4-week-old baby will need 2-3 night feeds.
Breastfeeding – Mums need to be sure they position their baby correctly at the breast. This means holding the baby horizontally across their chest, close to their body. The baby's mouth should be level with the nipple, and the head tilted backwards a little. By rubbing the nipple over the baby's lips, this will stimulate them to open their mouth wide. They need to have the whole areola (the coloured area of the nipple) in their mouth. As they feed, you can look down into their eyes, making feeding a close, loving experience, says Dr. Lee.
A new baby should be put to the breast regularly and often. To start with, they can only manage small amounts of milk, but as they grow stronger and mature, this will settle into 8-12 feeding times a day, with 2-3 feeds at night. Try to do 15 minutes on each breast. The baby will let you know when they are hungry. It doesn't matter that you don't know how much milk they have had. If they are content and gaining weight, that's all you need to know!
Bottle feeding – Baby feeding and nutrition are the most fundamental things for a baby's growth and development. Start by choosing a first infant formula. There is no 'best' formula, and note that paying extra does not mean it is better. Infant formula is made of cow's milk protein with other additives such as lactose, vegetable and fish oils, vitamins and minerals. If you are unsure what to go for, ask your midwife or health visitor, says Dr. Lee.
The ingredients of formula milks are regulated in the UK and must meet the standards of the Infant Formula and Follow-on Formula Regulations 2007.
Vegetarian milk made from soy protein is not recommended for babies under 6 months of age. Vegan mothers and babies are recommended to breastfeed until at least 6 months of age.
Always prepare the formula milk exactly in accordance with the manufacturer's instructions and using sterile equipment, says Dr. Lee.
You can supplement breastfeeding with bottles of formula milk, but this is not recommended because breastmilk is produced on a demand and supply basis. If you put the baby to the breast less often, the breastmilk supply will diminish. Instead, you can express breastmilk, and it can be given in a bottle if you need to. You can breastfeed a baby until the age of 2 or beyond if it suits you both.
Baby poop can vary a lot. It also differs if a baby is breastfed or bottle-fed, says Dr. Lee.
A breastfed baby will have runny, golden brown or yellow-green stools. Their poo may smell sweet. They may poo anything from several times a day to only a few times a week. Breastfed babies are unlikely to get constipation.
A bottle-fed baby will have darker brown or dark greenish stools, often harder and more formed. Their poo has a more typical poo smell. They may poo several times a da or several times a week. They can suffer from constipation, although this should not be the case if they are well and their feeds have been mixed correctly, says Dr. Lee.
When to call the doctor – If you feel your baby has not had a poo for a while and seems distressed, appears to be straining to pass a stool, or if there is blood in the poo or it is an odd colour, for example, white or black, call your GP.
Your baby’s health and safety: Tips for a 4-week-old baby
Ensure your baby has a safe place to sleep. They should sleep in their own cot and not in bed with you, or on the sofa. This increases the risk of sudden infant death syndrome (SIDS). Ideally, have their cot in your bedroom for the first 6 months, so it’s easy to feed them in the night and put them back to bed, and they are near you overnight.
Always place them on their back to sleep until they are at least 12 months old. Make sure there are no hazards in the cot. A baby just needs a well-tucked-in cot sheet to lie on, but no duvet or pillow. Small babies should not sleep with toys or soft toys, says Dr. Lee.
If you want to give a baby a dummy at night, this is perfectly reasonable and has been shown to reduce the risk of SIDS. However, you will find that as they lose the dummy in the night, you have to keep getting up to find it! It's easier if they can manage without one.
Take care to keep the umbilical cord stump cleaned with soap and water and gently pat it dry with a towel. It doesn’t need anything else applied to it.
Work on establishing a good feeding and sleeping routine.
Ensure you have a properly fitted baby car seat. Never take a baby in a car without a proper car seat.
Choose a proper pram or pushchair that meets UK safety standards. Only take your baby out when they are correctly strapped in and safely supported.
Keep your baby out of strong, direct sunlight. Keep their limbs covered and get them to wear a hat. Use a sunshade or sun visor. Stay indoors or in the shade on hot days. A baby's skin is very delicate, and sunscreen is not recommended for babies under 6 months old.
Take your baby for their screening tests and their immunisations. In the UK, a baby has their first immunisations at 8 weeks of age. Having these vaccinations helps stop your baby from developing many serious diseases and has been shown to be safe and effective. Your baby will be given three doses of the DTaP/IPV/Hib/HepB vaccine. This will protect them from diphtheria, tetanus, pertussis (whooping cough), polio, haemophilus influenzae type B and hepatitis B. If you have concerns about letting your baby be immunised, speak to your GP, midwife or health visitor.
Learn how to take your baby’s temperature – this is easy. Have a digital thermometer in the house. If your 4-week-old baby has a temperature of 38C or above, you should phone NHS 111 or contact your GP surgery without delay. A young baby has an immature immune system and is more likely to have a serious infection that needs hospitalisation.
Don't leave your baby unsupervised, ever. Apart from monitoring them when they are asleep, you should ensure your baby is never left alone. Many parents use a baby video camera to watch their baby in their cot, which is extremely helpful and safe, says Dr. Lee.
Advice on practical parenting tips
Looking after a newborn baby can be quite a shock. After all those months of longing for the baby to be here, suddenly the reality of being on-call 24/7, seemingly indefinitely, coupled with the exhaustion and frustration, can be overwhelming, says Dr. Lee.
Try and relax. Babies have been being born for centuries, and somehow, women and babies do get through it. It doesn't last forever. Try and enjoy these moments as they pass so fast, and they are very precious.
Take all the help you can get. If your Mum or a friend, or a relative can stay and help you, let them. Can your partner get up at night to do some feeds? If so, let them do it. Plus, you need to care for yourself the best you can. Try and sleep when the baby sleeps. This is the best option, and all the chores can wait, says Dr. Lee.
Remember to eat well and to drink plenty of fluids, especially if you are breastfeeding. You can't care properly for your baby if you are not caring for yourself.
It’s often helpful to meet up with other new Mums. Sharing what is happening and getting hints and tips from each other is very useful, says Dr. Lee.
If you feel things are getting you down, talk to your midwife or GP early on. The baby blues are common and usually pass. However, postnatal depression is also common and needs professional help. Don’t ignore any negative feelings – open up about it to someone you trust. Treatments for postnatal depression include counselling, cognitive behavioural therapy and/or antidepressants, says Dr. Lee.
Helpful Reminders (e.g. vaccines, appointments for a 4-week-old baby
Going home with a new baby and adjusting to a new routine at home can be quite bewildering and even frightening. Read up about life with a new baby beforehand so you are well prepared. Information and knowledge are key!
All new mums are given a red book, which is a personal child health record. This is a record of your baby's immunisations and their weight and height. You can use the book to record any illnesses or medication. You should keep this book safe, says Dr. Lee.
Remember that all babies cry. This is their only method of communication. It doesn’t necessarily mean anything is wrong. It’s important to make sure they are not hungry, wet, dirty, or unwell. But once you have exhausted these possibilities, it’s something you have to see through and deal with the best you can. Don't beat yourself up over it. It doesn't mean you are doing anything wrong. Having said that, if you are concerned about your baby, you should not hesitate to speak to a doctor or a midwife,m says Dr. Lee.
One excellent source of information is the National Childbirth Trust (NCT). They offer excellent antenatal courses, parenting classes and workshops. Many women find participating extremely helpful and reassuring, adds Dr. Lee.
Meet the expert
Having worked for many years in the NHS, mostly as Lead Clinician within an integrated Community Sexual Health Service, Dr Deborah Lee now works as a health and medical writer, with an emphasis on women's health, including medical content for Dr Fox pharmacy. She has published several books and remains passionate about all aspects of medicine and sexual health. After completing her Medical Degree at University of Southampton Medical School in 1986, Dr Lee trained as a GP and after a number of years specialised in Sexual & Reproductive Health (S&RH).
Meet the author
Adejumoke Ilori is a Commercial Content Writer for Mother&Baby. A proud mum to a little girl, Adejumoke has built a career across various leading digital platforms, creating content that empowers women from all walks of life. She is passionate about sharing real-life stories, particularly those that focus on relationships, self-love, and the journey of motherhood, offering readers a relatable and authentic perspective.