Baby's fourth month: development, medical and sleep

Enjoying "Tummy Time"
Enjoying "Tummy Time" 

Visually your baby now has good eye contact with most things due to better depth perception and generally clearer vision, and uses her eyes to express emotion in conjunction with body language and vocalisation of sounds. She will often talk to herself when left alone and may even imitate adult gestures such as yawning. A lot of her behaviour may now be done in order to get a reaction from you. Your baby will also be more energetic and animated due to improved sleeping, digestion, vision, hearing and reflexes.

A four month old baby recognises many different scents, including those of her parents and can indicate a liking and disliking of smells with her facial expressions.

By the age of four months, your baby will be able to follow a moving object with her eyes and look around and smile at people she sees frequently, they will also like to grab dangling objects and may start to become easily distracted, making feeding more difficult.

His eyes are still maturing but he will begin to have improved depth perception, generally clearer vision and is just starting to differentiate textures. Visually they still focus on sections of objects rather than as a whole. Sometimes attention is so intense that it may seem as if your baby is trying to commit something to memory.

A baby will continue to learn hand-eye co-ordination and if you leave toys within reaching distance, babies will stretch out their hands to grasp them, in a raking or batting motion, which is the start of being able to hold something independently.

From four months onwards, babies rate of growth slows to between 140-170 grams per week. The most important thing to remember is that your baby gains weight regularly, not how much she gains.

Your baby’s little digits will start to work independently of each other, rather than being controlled all at the same time, and she will be able to distinguish her control over an object when she is holding it and she may also bring her hands together in front of her face. She could also start to take an interest in their hands and feet, and start to engage in actions such as grabbing toes, and opening and shutting her hands. Involuntary or deliberate rolling can start from four months onwards and she will stretch her legs out when on her stomach and makes steplike movements when held upright in a more controlled manner than before, all of which are early skills needed in order to crawl later on. If she successfully grasps a toy, it will be for only a few seconds with her palm and curled fingers and if she becomes distracted she will drop the toy instantly.

This can be the time when babies roll over from their stomach to their back, with the intention of moving around a room, and start to resist having nappies changed. They may not repeat this behaviour immediately – there may be a few weeks in between the first time and the second time. Babies may accidentally slip themselves from their stomach onto their back while on their stomachs but it does not mean they know to roll yet and babies who spend less time on their stomachs during play time will tend to do this later.

If your baby can hold their head up well at this age, you may want to prop him up in a seating position or stand in an upright position bearing his own weight with your help or some other kind of support. Both positions assist in muscle development and you should allow your baby to have a view of his surroundings wherever he is as his eye sight is improving every day.

Her hearing is at the stage where she can hear soft sounds as well as louder ones and will start use the consonants m, k, g, p and b in her babbling, and she may even combine consonants with vowels. She may cry less because babies are able to distract themselves by four months of age.


From four months onwards, babies rate of growth slows to between 140-170 grams per week. The most important thing to remember is that your baby gains weight regularly, not how much she gains. Weight gain and growth come in spurts, usually at three weeks, six weeks and three months as well as randomly.

A daily bath isn’t necessary so long as your wash your baby’s face regularly and clean them carefully after each nappy change to avoid nappy rash. This is a general term that can be applied to a number of different types of dermatitis and the most common cause is bacteria in baby’s faeces, on her skin or in her clothing, and it can be aggravated by thrush and cloth nappies washed in soap. It can be difficult to get rid of prevent it by carefully cleaning babies skin with baby wipes every time you change your baby’s nappy, allowing their skin to dry completely after this and ensuring your baby’s nappy is changed whenever they are wet . Once they have a rash apply cream such as paw paw ointment, bepanthen, or a product suggested by your pharmacist.

At four months your baby will also need their second jab for diphtheria, tetanus, whooping cough, polio, haemophilus influenza b, Hep B, Pnuemococcal conjugate.

Some babies may begin to express an interest in solids at four months, which is two months earlier than the recommended time but many parents feel that they should wean if they have a very active, very tall or very hungry child who always wakes to be fed at night, to help their child continue to thrive. But growth spurts may start from four months onwards and this can affect hunger and feeding patterns, and starting babies on solids when they are less than six months old should only occur if recommended by a health professional and only if your baby can hold her head up very well, has lost her tongue thrust reflex and open her mouth to take food from a spoon. You’ll notice starting on solids is not listed as a “possible” milestone for this age group and this is because it’s not usually necessary or desirable.

Most babies should weigh twice the amount they were at birth and will have baby fat. Their rate of growth will have slowed to around 140 grams per week.

Babies can start to associate night time with longer sleeps as you keep play sessions for daylight hours and do less stimulating activities as it gets darker.

There is no set amount of time that a four month old baby will sleep. Some will sleep for 12 hours or more at night and have one or two long naps a day. Others will break it up more and have an eight hour sleep at night and shorter day naps, and others will only be sleeping for four or five hours for both day and night. Every baby sleeps according to their own needs. You need to associate night time with sleep time by playing with her during the day when she is awake and then using settling techniques at night. The total amount of sleep a baby typically should have is between 14-17 hours each day.

Most babies find warm water soothing and can fall asleep easily after a bath, particularly when baby lotions or bath gels containing lavender and chamomile are used, which are known for their calming properties. Look for gentle PH cleansers or mild soaps that are created for babies and use only a small amount. Keep them warm before, during and afterwards as a baby can grow to dislike bath time if they associate it with being cold and uncomfortable.