Your baby’s fourth trimester starts from the moment she’s born and lasts until she’s three months old. The term is used to describe a period of great change and development in your newborn, as she adjusts to her new world outside your womb.
You may find the term “trimester” odd, since your baby is already born. But think how much she still needs to develop over these next few months, from refining and developing all her senses and controlling her reflexes, to learning how to respond to you and your partner. The mental and physical strides your baby takes during her first three months are just as important to her development as those she took in your womb.
The fourth trimester is also a time for your baby to get used to the variety of noises, lights, smells, sounds and sensations of the outside world. Moving from the familiar comfort of your warm, dark and quiet womb (uterus), to a noisy, bright and often cold environment, is a major change for your baby. By offering her plenty of love and support in her first three months, you can make this transition easier.
Compared with other animals that can get up and walk from birth, your newborn totally relies on you for care, attention and love. At birth, your baby has only her instincts and reflexes to help her control her behaviour and movement.
At birth, your baby’s senses are limited and still developing. She has sight, but her vision is blurred. She can hear, but it’s difficult to pick up on individual sounds and voices. She can feel, but the reassuring and snug comfort of your womb has been replaced by disconcerting open space. The fourth trimester is a time for your baby to adapt to these changes with your help and support.
Although your baby's brain is well developed by the time she's born, her neural pathways and nervous system continue to develop after birth. Much of this takes place during her fourth trimester. Your baby's brain is like a sponge, soaking up everything that happens to her. The more her brain is stimulated, the better the connections in her brain (synapses) will become.
In the first three months of life, you may notice your baby:
- gradually breathing more steadily, startling less and developing more controlled movements
- settling into more consistent sleep and feeding patterns
- being able to sleep through noise or disturbances
- learning to soothe herself or crying out for your attention to comfort her
- improving her social skills, so she can interact with family and friends, objects or music with greater attention and for longer periods of time
By the end of your baby’s fourth trimester, you’ll have watched a remarkable physical, mental and social transformation in her.
Your baby is likely to cry more during her fourth trimester than at any other time in her life. Knowing that this is completely normal can help you cope with the inevitable worry and anxiety that a crying baby brings.
Your newborn is too young to have a fixed routine, and probably won’t be ready for one until she’s around three months. Until then it’s fine to feed or soothe your baby as soon as she cries. Contrary to what you may have heard from older relatives, this won’t spoil your baby. In fact, it will help her feel more secure, so she may even cry less.
Your newborn is going to sleep a lot, especially in the early weeks. Sleeping is good for her, as it helps her brain process all that wonderful sensory stimulation she’s receiving from you and your partner, while she’s awake.
But it may take a little while for your baby to settle into a sleeping routine. Coming from the constant environment of your womb, your baby has no concept of day or night yet. It will take weeks, perhaps months, for her to adjust her sleeping patterns to sleeping more hours at night. So for now, let your newborn sleep whenever she likes, around the clock.
Although it may seem odd, putting your baby down to sleep during the day in a noisy, bright environment is fine. It’s likely that she’ll be able to shut out this stimulation and just drift off, although not all babies can do this. You’ll soon see what works best for your baby.
As a newborn, your baby has a small stomach, so needs feeding little and often, with at least eight feeds every 24 hours.
As you get to know your baby, you’ll begin to understand the little cues and signals she makes that tell you she’s hungry. It’s easy to assume that crying is the first sign that she’s hungry, but it can be the last. Early signs to look out for include sucking on her fingers, turning her head and opening her mouth.
Picking up on these signs is useful for you both. If your baby reaches the point of crying, she may be too upset to latch on properly or settle down for a feed.
Your baby is too young for a feeding routine just yet. Feeding her on demand, whether she’s breastfed or bottle-fed, will help to soothe and reassure your baby that she’s well looked after. If you’re breastfeeding, this will also help to match your milk supply to your baby’s needs.
Mealtimes aren’t just about feeding, of course. Feeding time is also a great opportunity to sit down with your baby and have a cuddle, some eye contact, or even enjoy skin-to-skin. Your baby will love these reassuring signs that you’re focused on her every need.
Although many of your baby’s senses are well-developed at birth, they continue to improve throughout her fourth trimester.
Her sight develops most rapidly in the first three months of life. By her second to third month, her vision won’t be so blurry and she’ll be able to tell the difference between objects. By around eight to nine weeks old, her vision will almost be the same as an adult’s.
Look out for signs that your baby is alert, ready and willing to look at things, but also signs that she’s becoming overwhelmed, such as turning away or breaking eye contact.
Your baby is born with the ability to smell and taste. She’ll recognise and be comforted by your familiar scent as soon as she emerges from the womb. This familiarity with your smell is what drives her to turn her head and bob about for your nipple, trying to find her first feed.
Your baby can hear when she’s still in the womb and will have already learned to recognise the sound of your voice. You may notice her turning her head when you or your partner speak. She’ll enjoy listening to you talking and will feel soothed and comforted by familiar sounds and voices. By the time she reaches three months, your baby may even be starting to make sounds of her own to get your attention.
In your womb, your baby was constantly “held” by your amniotic fluid. She may find it upsetting to be thrust into a world where she’s expected to lie down on her own sometimes. Regular skin-to-skin with your baby can help to stimulate her sense of touch, soothe fussiness and ease crying, stabilise her heart rate and improve breastfeeding. Babywearing (carrying your baby about in a sling or baby carrier) can mimic the gentle movement your baby felt in the womb and swaddling may help her to feel more secure and snug.
At birth, your baby is almost entirely physically helpless. She has some instinctive responses and reflexes and is able to move her head about to root for your breast.
Giving your baby daily tummy time can help her to develop physically. By the time she’s three months old, she may be able to push herself up on her forearms, raise her head and even keep it in position for a few moments. Tummy time helps to encourage movement and build strength in your baby, so you can start soon after her birth.
Understanding the environment your baby lived in for nine months can be a useful tool in helping to soothe and support her through her fourth trimester. It may also help you to cope with unexpected crying or fussiness, if you know how much your baby needs to adapt to her new world.
There are things you can do to help your baby make this transition. Some babies adapt more easily to the outside world than others, so you may find that you manage without some of these ideas, while others are more essential:
- Skin-to-skin. This helps to calm and soothe your baby. She will be reassured by your warmth and your smell, and the familiar sound of your heartbeat helps to regulate her own. Skin-to-skin also encourages your baby to latch on for breastfeeding.
- Feeding on demand. Giving your baby nourishment whenever she needs it, whether you’re breastfeeding or bottle-feeding, helps her to meet her energy needs and reassures her that she’s well looked after.
- Babywearing. Using a sling helps mimic the gentle movement and snug comfort that your baby experienced in your womb. If your baby is fussy, carrying her across your chest may soothe her, as she tunes into your heartbeat.
- Swaddling. Safe swaddling creates a feeling of containment, just like your womb. It may help your baby to sleep better and soothe her if she's been crying. Make sure you know how to swaddle safely.
- Swinging and movement. Walking around while you hold your baby may be more soothing for her than sitting down and cuddling her. In your womb, she was rocked and lulled by your everyday movements. Mimicking this gentle swaying and rocking may help to comfort your baby if she’s crying or fussy.
Every baby is different. Not all babies like being swaddled or carried around. Your baby will soon let you know if she doesn’t like something.