Week 19

Days 127 to 133 · 18 weeks 0 days to 18 weeks 6 days old · about 4 months This week many babies measure about 63 cm (24.8 in) and weigh about 6.8 kg (15 lb). As always, babies vary widely, and what counts is your baby following their own curve on the growth chart. Two big developments are under way: your baby's reach is becoming accurate, so hands land on what eyes have chosen, and the first babbling sounds may begin. For you, sleep is probably the topic on your mind. Many parents of four-month-olds are tired enough to wonder whether they should be doing something to change their baby's nights. This week looks honestly at what is normal, at the main approaches to sleep, from gentle to more structured, and at what the evidence does and does not say.

Day 127 · 18 weeks 0 days old

Your baby's hands now go where their eyes do

A few weeks ago your baby swiped at toys with wide, hopeful arms, connecting mostly by luck. Now something is changing. Many babies between about 4 and 5 months begin to reach with purpose: they look at an object, move one or both hands straight towards it, open their fingers just before contact and close them around it.

This skill joins up several systems at once. Vision has sharpened, depth perception is improving, and your baby has better control of the shoulders, arms and trunk. Holding the head steady helps too, because a stable head means a stable view.

At first, the grasp is a whole-hand affair, with the palm and fingers working together like a mitten. The neat pincer grip between thumb and finger comes much later in the year. Babies also start passing objects from one hand to the other around now or in the coming weeks.

Reaching is easier when your baby is well supported. Sitting propped in your lap, lying on their back, or on their tummy leaning on one forearm are all good positions to practise. Some babies reach eagerly at 4 months, others closer to 6. Both are within the usual range.

Try this: Sit your baby on your lap facing a table and place a ring or soft block within reach, then watch how they plan and make the grab.

Day 128 · 18 weeks 1 day old

Babbling is on its way

Cooing, those long, open vowel sounds, has filled your home for weeks. Now you may hear something new: your baby joining a consonant to a vowel, or blowing raspberries, squealing, growling and playing with pitch and volume. These experiments are the start of babbling.

Early babbling often sounds like single syllables or strings of vowels with the odd "g", "b" or "m" mixed in. The repeated chains, like "ba-ba-ba" or "da-da-da", usually come a little later, often between about 6 and 9 months. Each baby follows their own timeline, and some are simply quieter than others.

Babbling is not random noise. Your baby is practising the mouth movements of speech and listening closely to the sounds of the language around them. Babies who hear two or more languages babble too, and they are not slowed down by it.

The most helpful thing you can do is answer. Pause after your baby makes a sound, then reply as if it were a real remark, and wait again. These little conversations teach the rhythm of turn-taking long before words arrive. Call your baby's doctor if your baby does not react to loud sounds, does not turn towards voices, or makes very few sounds, or if you have any worry about their hearing. A hearing test is quick and simple at any age. Try this: Copy one of your baby's sounds back to them today, pause, and see whether they answer you with another.

Day 129 · 18 weeks 2 days old

Night waking at this age is normal

Many parents hope that by four months their baby will sleep through the night. Some babies do, but plenty do not, and both are normal. As you read in week 14, sleep cycles change around this age, so many babies wake more often than they did a month ago.

All humans wake briefly between sleep cycles, usually without remembering it. The difference is that a baby who fell asleep while feeding, rocking or being held may wake fully at those moments and call for the same help to drift off again. This is not a bad habit. It is simply how babies learn to connect sleep.

At this age, many babies, particularly breastfed babies, still need one to three feeds in the night. Growth, a new skill such as rolling, a cold or a busy day can all bring a run of rough nights. "Sleeping through" in research often means just five or six hours in a row.

So before choosing any approach, it helps to ask a simple question: is this a problem for your family? If you are coping and your baby is thriving, there is no need to change anything. If exhaustion is affecting your health, your mood, your work or your safety, it is reasonable to look for ways to make nights easier.

Try this: For the next three nights, jot down when your baby wakes and what settles them, so you can see the real pattern rather than the blur.

Day 130 · 18 weeks 3 days old

Gentle ways to help your baby sleep

Gentle approaches aim to improve sleep slowly, with you close by and responding to every cry. They usually take longer to show results, but many families find them a comfortable fit, and they can start at any age. The foundation is a calm, predictable routine before bed, as you read in week 8: the same few steps in the same order, such as a bath or wash, pyjamas, a feed, a song and lights out. A dark room, a comfortable temperature and steady white noise can also help.

From there, some parents try gradually loosening the link between feeding and falling asleep. You might move the bedtime feed earlier in the routine, so your baby is drowsy but not fully asleep when you lay them down. If they protest, you can pick them up and settle them, then try again. Over days and weeks, many babies learn to finish falling asleep in the crib.

Another gentle method is to change one sleep association at a time: rocking a little less, then patting instead of rocking, then simply resting a hand on their chest. Small steps, repeated consistently, add up. Expect some setbacks, especially during illness or teething.

Try this: Choose one small change to tonight's bedtime, such as moving the feed before the bath or song, and keep it the same for a week.

Day 131 · 18 weeks 4 days old

Gradual methods that shift you to the doorway

In between the gentlest approaches and the more structured ones lie gradual methods. They give your baby more chance to settle on their own, while you stay present and reassuring.

One common version is often called the chair method or camping out. You sit in a chair beside the crib while your baby falls asleep, offering your voice or a touch if needed. Every few nights you move the chair a little further away, towards the door and eventually outside the room. Your baby can always see or hear you, but the help you give shrinks over time. Another approach, sometimes called parental presence or fading, has you lie down or sit in the room, quietly, without engaging much, until your baby is asleep. Over a couple of weeks you leave earlier, then earlier again. These methods usually take one to three weeks and involve some crying, though often less intense than with more structured methods. Consistency matters more than which version you pick. If you start, try to keep going for at least a week before judging, and agree in advance on what you will do at 2 a.m., when good intentions are hardest to keep.

Try this: Talk through, at a calm moment rather than at night, which method feels realistic for your family and what would make you stop or pause.

Day 132 · 18 weeks 5 days old

Structured sleep methods and what the research says

More structured approaches are often called sleep training. The best known is graduated extinction, sometimes called controlled comforting or check and console. You put your baby down awake after a calm routine, leave the room, and return at set intervals, gradually longer ones, to reassure them briefly without picking them up. Extinction, leaving a baby until they fall asleep without checking, is the strictest version, and many families find it too hard.

Most sleep experts suggest waiting until at least 6 months for these methods, when night feeds are less likely to be needed and your baby is ready to learn. They are not right for a baby who is unwell or not growing well. Ask your baby's doctor or nurse first if you have any doubt.

Here is what the research shows. Structured methods often improve sleep within a week or two, and they can lift parents' mood. Well-designed studies, including one that followed children for five years, have found no lasting harm to emotional health, behaviour, stress levels or the bond with parents. The benefits also tend to even out over time: many babies who are not sleep trained sleep just as well a year or two later.

So you can choose sleep training, or decide it is not for you, with confidence either way.

Try this: Write down, in one sentence, what you most want from your nights, such as "four hours of unbroken sleep for each of us", and use it to judge any approach.

Day 133 · 18 weeks 6 days old

Making a sleep plan together

Whatever approach you choose, or if you choose none, babies do best when the adults around them respond in roughly the same way. A plan that one parent believes in and the other quietly undoes at midnight tends to bring the hardest of both worlds: lots of crying and no progress.

A good plan is simple. It covers the bedtime routine, what each of you does at each waking, and who is on duty when. It might decide that one parent handles the first half of the night and the other the second, or that the parent who is not breastfeeding takes every waking that is not a feed. It should also say when you will review the plan, perhaps after one or two weeks. Some things never change, whatever your approach. Your baby sleeps on their back, on a firm, flat surface, in their own crib, bassinet or cot, with nothing loose in it, and in your room for at least the first 6 months. If a plan leaves you so tired that you might fall asleep holding your baby on a sofa or armchair, that is a sign it needs adjusting.

If you are parenting alone, a plan still helps, and so does asking someone to take an occasional night or early morning.

For your partner: Offer to own the next plan conversation: put the questions above on paper, choose a calm time, and take the first full shift once you have agreed.