Fetal Growth Inside Your Belly: Third Trimester

Fetal Growth Inside Your Belly: Third Trimester
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Congratulations! You’ve reached the third trimester of pregnancy. At this stage, your belly begins to look larger as the baby continues to grow inside.

When the egg is fertilized and attaches to the uterine lining, the hormone hCG is released, which can be detected with a pregnancy test. In the previous discussion, you learned about the changes that occur in the first and second trimesters.

Pregnancy is usually divided into three stages, known as trimesters. Here’s what happens to your fetus in the third trimester, as reported by WebMD:

 

Week 27:

Your baby has started forming a sleep pattern. However, it won’t always match yours, and sometimes you may feel a sudden kick during the night.

 

Week 28:

The fetus now measures about 25 cm in length. He begins to blink, cough, hiccup, and even experience dreams.

 

Week 29:

The baby is getting stronger, so you’ll feel more powerful kicks and movements. He also becomes more responsive to light, sound, and touch, whether you talk to him or gently touch your stomach.

 

Week 30:

As your baby continues to grow, your belly expands further. This change may also increase your shoe size, making your old shoes feel too tight.

 

Week 31:

At this stage, your baby’s lungs are still not fully mature. Stay alert for continuous contractions.

 

Week 32:

The fine hair called lanugo starts shedding. By now, your baby may be as big as a melon.

 

Week 33:

All the bones in your baby’s body are starting to harden, but the skull remains soft, so extra care will be needed during delivery.

 

Week 34:

Your baby’s digestive, breathing, and nervous systems are already functioning independently. The head also begins to move into position in the birth canal.

 

Week 35:

As the fetus grows, he starts finding a comfortable position, which can make you feel the urge to urinate more often.

 

Week 36:

The protective coating on your baby’s skin, known as vernix caseosa, starts to fade. This indicates your baby is preparing for birth. To monitor the condition closely, it’s recommended to schedule weekly checkups.

 

Week 37:

The baby’s immune system is ready, and the body prepares for delivery. You may notice mild contractions starting.

 

Week 38:

Reflexes become sharper, and the baby feels more cramped inside the womb. If contractions become stronger, it’s a sign to get ready for labor.

 

Week 39:

Contractions and back pain intensify. Labor can begin at any moment.

 

Week 40:

Sometimes, your baby may not arrive on the expected due date. Birth can happen earlier or later, and it may be through normal delivery or by cesarean section. Whatever the case, congratulations on becoming a mother! Your baby is now ready to meet the world and will first be nourished with your colostrum.

 

As you approach the end of pregnancy, your doctor may recommend more frequent visits. Watch for signs that labor is starting, such as regular and ongoing contractions, increased fetal movements, the release of amniotic fluid, or discharge of mucus and blood from the birth canal. If you notice these symptoms, immediately seek care at the nearest health facility.

 

Looking for more information about pregnancy, breastfeeding, women's and children's health? Click here!

 

Writer : Agatha Writer
Editor :
  • dr Hanifa Rahma
Last Updated : Monday, 8 September 2025 | 05:06

Shroff A. Slideshow: Fetal Development Month by Month (2021). Available from: https://www.webmd.com/baby/ss/slideshow-fetal-development

 

Cleveland Clinic. Fetal Development: Stages of Growth (2020). Available from: https://my.clevelandclinic.org/health/articles/7247-fetal-development-stages-of-growth.