How babies develop in their 4th month

Appointments – What’s coming up in the 4th month?

U4: If the U4 did not take place in the third month of life, now is the time. Remember to bring the certificate your health insurance fund sent you in advance. This must be signed by the paediatrician after the examination so that you can return it to your health insurance fund or the competent authority.
Booster vaccination: The second six-in-one vaccination boosts the primary immunisation begun with the first dose. Even if your baby showed no side effects after the first vaccination, they may react to the second with fever, lethargy or diarrhoea – as a precaution you should have something to reduce fever at home.
Finding a babysitter: Even though many parents initially find it hard to leave their few‑months‑old baby with someone else, a short break from everyday life is worthwhile. If there are no grandparents or experienced friends available, acquaintances may be able to recommend a trustworthy babysitter, even if only for a few hours.

Important developmental milestones in the 4th month

Physical development: Your baby has roughly doubled their birth weight in the fourth month. Most babies no longer need feeding so frequently, as they drink larger amounts and stay satisfied for longer.
Sleep: You may now sometimes notice that your child sleeps six or seven hours at a stretch at night. It usually takes a while before this becomes the norm. Overall, nights become a little calmer as your child develops a regular sleep rhythm.
Muscles: Many babies can hold their head up well in tummy position in the fourth month. When they support themselves on their arms their field of vision widens – at the same time they exercise the muscles they will later need for crawling.
Laughing and "talking": Your baby already shows quite clearly what they like and what they do not. They have learned to laugh out loud and even occasionally try to respond to simple sounds like "Buh" or "Bah" when they hear them.

How much should my child weigh at 4 months?

Physical development now progresses somewhat less rapidly than in the first months of life, so there are not very large changes in height and weight. Instead, motor development of your little one comes to the fore as they learn to control their body. In the fourth month your baby is about 62 to 64 centimetres long and weighs between 6,400 and 7,000 grams.