42 Week Old Baby: Development, Milestones & Care Tips

Your 42-week-old Baby – Development, Milestones & Care

Medically Reviewed By
Dr. Gunjan Baweja (Paediatrician)
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At 42 weeks, your baby is now on his way to his toddler phase. So you can expect fussy eating habits or tantrums if he is not given things he demands. Your baby will also start being a great problem solver at this age. Some babies will quietly try and solve a problem (like getting a toy which is out of reach), and some will use every single method and still not give up until they get what they want. Your baby’s cognitive development will be on a high at 42 weeks and he will want to explore more of his world.

Your 42-week-old Baby’s Development

During this age, separation anxiety can still be an issue for many babies, as will be the wakefulness at night. But babies this age may take great joy in exploring their surroundings to the best of their abilities. Be ready for a lot of contents of boxes and containers to be strewn along the floor. As your baby will also be constantly moving, you have to be ready to keep running around and catching him when he runs off in the middle of feeding, changing or bathing. At this stage, your baby will be able to sit confidently, walk fast while holding onto things and also possibly stand with no support. He can also try to bend down and pick up a toy while he is standing. If your baby is not walking yet, don’t worry. Many babies take their first steps only around 12 months or later. At 42 weeks, your baby will be getting smarter. Soon he will be able to catch the concepts of distance, depth, time, and cause and effect. He will incorporate these into his play, like stacking and re-stacking blocks, rolling a ball or separating cornflakes from the cut fruits on his plate.

[Also Read: 10-Month-Old Baby Development]

Your 42-week-old Baby’s Developmental Milestones

You can expect to see the following 42-week-old baby milestones in your little one:

  • Your baby will be able to get into a sitting position from lying on his stomach.
  • Your baby will be able to walk fast by holding onto some furniture.
  • Your baby will be able to understand when you say ‘no’ even though he may not obey it.
  • Your baby will be able to clap hands and wave at you.
  • Your baby will be able to bend down while standing and pinch up objects between his fingers.
  • Your baby will be able to roll around on the floor.
  • Your baby will be able to start understanding instructions like ‘come to mama’ or ‘put the ball in the box’ if you accompany it with gestures.
  • Your baby will be able to work out solutions to get something he wants which is out of his reach.

[Also Read: 10 Month Old Baby Milestones]

Your 42-week-old Baby's Developmental Milestones


Your baby might exhibit irregular feeding patterns at this stage as his feeding behaviour changes often. This is because he is still adjusting to having solid food in his diet along with breast milk. So it is very normal for him to one day eat his meals and snack fully and the next day, prefer only breast milk and nothing else. Usually, at night, he will be up due to teething pain and so might seek your breast out more to soothe himself to sleep. Know that at 42 weeks, breast milk still makes up for most of your baby’s daily nutrition, and solid foods are secondary. So it is best to work out your baby’s expressed breast milk requirement when you are away and calculate the average number of feeds he would have starting from a base level. At 42 weeks, your baby may not need a bottle; and he may use a cup. So in case you are away from your baby, you can give your baby’s caregiver the day’s estimate of breast milk and ask them to give it to your baby in small amounts. Ask them to keep a record of his intake so that you can pump your breast milk according to that.

[Also Read: 10-Month-Old Baby Food]


Your baby will be crawling a lot at 42 weeks of age. Studies show that sleep disruption accompanies crawling and your baby will exhibit disturbed sleep patterns for around three months after he starts crawling. Doctors say that crawling increases your baby’s activity and influences his ability to regulate his movement. This causes a period of instability which can result in increased wakefulness at night. This period can be particularly difficult for a parent, as a baby’s enhanced mobility and teething can cause him extremely disturbed sleep. His sleep maturation can go through peaks and troughs over the next few years.

Your baby will be crawling a lot at 42 weeks

Care Tips for Your 42-week-old Baby

Here are a few ways you can care for your 42-week-old baby:

  • Bathe your baby every day in a large plastic tub. If you want to bathe him in a larger tub, make sure to use protective bumpers on the sides and a non-slip mat for his safety.
  • Stay away from using clips and bows on your baby’s hair; they are potential choking hazards. No need to use a separate conditioner for your baby’s hair, a tear-free de-tangling shampoo is enough.
  • If you are planning your baby’s first haircut, choose a hair care professional who knows how to cut baby hair. Plan it when your baby is not tired or hungry. Give your baby his favourite toy to distract him during the process.
  • Introduce a sippy cup to your baby and show him how to grasp the handles and drink it, to wean him away from the bottle.
  • Avoid feeding your baby food which can choke him, like whole grapefruit or raw carrots. Always feed diced and cooked fruits, cheese and vegetables that have been peeled.
Bathe your 42-week-old baby in a large tub with safety mats underneath

Tests and Vaccinations

Most doctors do not schedule any regular checkups at ten months of age.

1. Tests

The doctor will check your baby’s height and weight to track his growth development. He may also take a blood test to check the levels of iron, haemoglobin or lead in your baby’s blood if he exhibits symptoms of anaemia.

2. Vaccinations

Your child may require to take the final dose of the Hepatitis B vaccine (out of 3-4 doses) and a dose of the influenza vaccine (as recommended by the doctor) at 42 weeks of age. He may also require the third dose of the IPV (polio) vaccine between 6-18 months.

Games and Activities

You can play the following games and activities with your 42-week-old baby:

  • Play a game where he can hear simple instructions. For instance, give him a ball with a box and ask him to put the ball in the box. Or put his teddy bear somewhere and ask him, ‘Where’s your teddy?’. This can help improve problem-solving skills in your baby.
  • Play a game of putting toys back into a box with your baby. This can help him learn the basics of cleaning up from a tender age.
  • Sit across the room from your baby and ask him to come to you. This game will help him develop his motor skills as he cruises or crawls to you.

[Also Read: 10 Month Old Baby Activities]

Play mentally engaging games with your 42-week-old baby

When to Consult a Doctor

You should consult a doctor when you notice the following in your baby:

1. Insect Stings or Bites

This can be harmful to babies at this stage. If you notice a sting on your baby, remove the stinger by scraping it, wash the area with water and soap, and use an ice-pack/baking soda and water on the sting to relieve pain. If the area is red and swollen even after 24 hours or your baby starts to vomit or has a fever, consult a doctor.

2. Allergic Reaction

If your baby is wheezing, has trouble in breathing, has a rash, or swelling on the tongue, hands or face, or is in shock, consult your doctor as your baby might be having an allergic reaction or anaphylactic shock to something.

42-week-old infant development is full of surprises, fun, sleeplessness, spills, and messes. It may be trying for you, but enjoy it while it lasts. Have fun with your baby!

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