posted 8th June 2026
Baby Development in the Third Trimester
The third trimester is an exciting stage of pregnancy. As you move closer to meeting your baby, remarkable changes are taking place every week. From rapid growth and weight gain to developing essential skills needed for life outside the womb, your baby is preparing for their arrival into the world.
In this blog, we'll explore how your baby develops during the third trimester, what milestones to expect, and how ultrasound scans can help monitor your baby's growth and wellbeing.
When Does the Third Trimester Begin?
The third trimester begins at 28 weeks of pregnancy and continues until birth, typically around 40 weeks.
During these final months, your baby experiences significant growth and development, while your body continues preparing for labour and delivery.
Weeks 28–31: Rapid Growth Begins
At the start of the third trimester, your baby is becoming stronger and more active.
What's Happening?
- Your baby's eyes can open and close.
- They begin to recognise light and darkness.
- Brain development accelerates.
- The nervous system continues to mature.
- Fat starts building beneath the skin.
By 28 weeks, your baby weighs approximately 1 kilogram (2.2 pounds)and measures around 38 centimetres long.
You may notice stronger kicks, stretches, and movements as your baby grows.
Weeks 32–35: Building Strength
During this period, your baby's organs continue maturing and preparing for life outside the womb.
Key Developments
- Bones are fully formed but remain soft.
- The lungs continue developing.
- The immune system becomes stronger.
- Your baby practices breathing movements.
- Fingernails and toenails continue growing.
Many babies begin moving into a head-down position during this stage, preparing for birth.
By 34 weeks, your baby may weigh around 2.2 kilograms (5 pounds).
Weeks 36–40: Final Preparations
In the final weeks of pregnancy, your baby focuses on gaining weight and fine-tuning essential body systems.
Your Baby Is:
- Storing fat to help regulate body temperature after birth.
- Developing stronger sucking and swallowing reflexes.
- Continuing lung maturation.
- Practising movements and breathing patterns.
Although there is less room to move, you should still feel regular movements throughout the day.
By full term, your baby typically weighs between 2.7 and 4 kilograms (6–9 pounds) and measures approximately 48–53 centimetres long.
How Your Baby's Appearance Changes
Throughout the third trimester, your baby begins to look more like the newborn you'll soon meet.
Physical Changes Include:
- Smoother skin as body fat increases.
- Less fine hair (lanugo) covering the body.
- More defined facial features.
- Longer hair on the head in some babies.
- Rounded cheeks and fuller limbs.
By the end of pregnancy, many babies look remarkably similar to how they will appear at birth.
Monitoring Growth During the Third Trimester
Growth scans can provide valuable information about your baby's wellbeing during the final months of pregnancy.
These scans can help assess:
- Baby's growth and weight
- Position within the womb
- Placenta location
- Amniotic fluid levels
- Overall development
For many parents, seeing their baby during a third-trimester scan is also a wonderful opportunity to observe facial features, movements, and expressions.
What Movements Should You Expect?
Your baby's movements may feel different during the third trimester.
Instead of sharp kicks, you may notice:
- Rolling movements
- Stretching
- Elbows and feet pressing against your abdomen
- Rhythmic hiccups
It's important to become familiar with your baby's normal movement pattern and seek advice from your healthcare provider if you notice any significant reduction in movements.
Preparing to Meet Your Baby
The third trimester is often a time of anticipation, excitement, and preparation. As your baby continues to grow and develop, each week brings you closer to one of life's most memorable moments.
Regular antenatal care and ultrasound assessments can help ensure both you and your baby are progressing well throughout this final stage of pregnancy.
Supporting Your Pregnancy Journey with Daisyscan
At Daisyscan, we understand how special the third trimester can be. Our experienced team provides professional ultrasound services in a warm and welcoming environment, helping you monitor your baby's growth while creating lasting memories.
Whether you're booking a growth scan or simply looking forward to seeing your baby again before birth, we're here to support you every step of the way.
Book Your Third Trimester Scan Today
The final months of pregnancy are filled with incredible milestones. A third-trimester scan can provide reassurance, valuable information, and a wonderful opportunity to connect with your baby before their arrival.
Book your appointment with Daisyscan today and enjoy a closer look at your baby's journey as you prepare to welcome them into the world.