The U3 examination takes place in the 4th to 5th week of life and is often the first detailed appointment for many families at the pediatrician's office. During this visit, your baby will be thoroughly examined, weighed, and measured. A special focus is on the hip ultrasound, which can detect hip development issues early on.

The U3 also provides time for your questions—about weight, breastfeeding or bottle feeding, sleep, crying, and the first vaccinations. The goal is not to check if everything is already perfect in family life, but to provide medical support and early assistance.

U3 at a Glance

Timing: 4th to 5th week of life
Location: Your pediatrician's office
Focus Areas: Physical development, growth, hip ultrasound, nutrition, sleep, and vaccination advice

You can find the exact examination window in the Yellow Examination Booklet and in the tio App.

What is Examined During the U3?

The pediatrician will examine your baby from head to toe. This includes:

  • Weight, body length, and head circumference
  • Heart, lungs, and abdomen
  • Skin, head, and fontanelles
  • Eyes, mouth, and hearing reactions
  • Spine, arms, and legs
  • Muscle tone and innate reflexes
  • Movement behavior and general development

Additionally, the results of the newborn screenings are reviewed, and further steps are discussed if necessary.

How is My Baby's Development Assessed?

At four to five weeks, your baby is still at the very beginning of their development. Therefore, the U3 is not about checking off individual milestones.

The assessment includes whether your baby:

  • Moves spontaneously,
  • Shows age-appropriate muscle tone,
  • Sucks and swallows strongly,
  • Responds to voices and touches,
  • Can briefly focus on faces or light,
  • Lifts or turns their head briefly when on their stomach.

Not every baby will show all these abilities yet. The overall development is what matters, not a single observation.

Why is the Hip Ultrasound Part of the U3?

The hip ultrasound is an integral part of the U3. It shows whether the hip joints are developing normally and if the hip heads are stable in the sockets.

The examination:

  • Is painless,
  • Involves no radiation,
  • Takes only a few minutes, and
  • Detects hip dysplasia or developmental delays early.

If an issue is detected early, it can usually be treated very well, and later problems can often be avoided.

Is My Baby Gaining Enough Weight?

After the initial weight loss, babies should now be gaining weight again. It's not about a single measurement but the overall weight development.

The doctor will assess, among other things:

  • the previous weight progression,
  • drinking habits,
  • wet diapers,
  • wakeful periods and general condition.

If your baby is having trouble drinking, gaining little weight, or frequently vomiting, potential causes will be explored together.

Which vaccinations are discussed at the U3?

The U3 is the first major appointment for vaccination counseling. Together, the vaccination schedule for the coming months will be discussed.

Standard vaccinations against diseases such as diphtheria, tetanus, whooping cough, polio, Hib, hepatitis B, and pneumococci usually begin after the second month of life.

Depending on the age, the first rotavirus oral vaccine can also be planned or may have already been administered.

Bring the vaccination card if one has already been issued.

Vitamin K, Vitamin D, and Fluoride

At the U3, your baby typically receives the third dose of vitamin K, which protects against rare but serious bleeding.

Additionally, the following will be discussed:

  • how to continue daily vitamin D supplementation,
  • recommendations for fluoride, and
  • how these can later be combined with dental care.

The parents' situation is also part of the U3

The first weeks with a baby can be physically and emotionally exhausting. Lack of sleep, breastfeeding issues, or uncertainty are common for many families.

Therefore, you can also discuss your own situation during the U3. If you feel constantly exhausted, sad, or overwhelmed, or if you have difficulties in daily life, speak openly about it. Early support can be very relieving.

What should you bring to the U3?

Helpful items include:

  • Yellow examination booklet
  • Vaccination card (if available)
  • Your child's health insurance card
  • Relevant medical letters or screening results
  • Diapers and a change of clothes
  • Food or a bottle, if needed
  • A list of questions or observations

Make a note in advance of anything you've noticed about your baby's drinking, sleeping, crying, or development.

Typical questions for the U3

Many parents want to know at the U3:

  • Is my baby developing appropriately for their age?
  • Is the weight gain sufficient?
  • What does the hip ultrasound show?
  • When do the first vaccinations begin?
  • Is frequent crying or waking still normal?
  • What vitamins or supplements does my baby need?