Third trimester - 28-40 weeks

Third trimester - 28-40 weeks

This is the final stage of your pregnancy. As your due date approaches, your cervix will become thinner and softer in a process known as effacing. This is a normal and natural process that helps the birth canal (vagina) open during labour. Your doctor will check your progress with a vaginal exam as your due date gets closer. Be sure to ask any questions you may have about labour and delivery.

During the third trimester, your baby continues to grow, and your body prepares for childbirth. Below are some symptoms you might experience at this stage of pregnancy:

You may feel tired and breathless as your baby grows. This could sometimes be due to iron-deficiency anaemia. You will be offered blood tests to check your iron levels throughout your pregnancy.

You’re almost done! Some discomforts from your second trimester will still be there. Many women also have trouble breathing and need to go to the bathroom more often. This happens because the baby is getting bigger and pressing on your organs. Don’t worry; your baby is healthy, and these issues will improve after you give birth.

Some new body changes you might notice in the third trimester include:

• Shortness of breath may increase more easily.
• Heartburn: Try to eat smaller meals more frequently, stick to bland foods, and avoid eating late at night.
• Lower back pain is common due to the natural arch of your back as your growing belly shifts your weight forward.
• Swelling in the ankles, fingers, and face: If you experience sudden or extreme swelling, or if you gain weight rapidly, contact your doctor immediately, as this could be a sign of preeclampsia.
• Haemorrhoids may occur.
• Tender breasts: You might notice leakage of a watery pre-milk known as colostrum.
• Your belly button may protrude.
• You may have trouble getting comfortable while sleeping.
• The baby may "drop," moving lower in your abdomen.
• Contractions can happen and may indicate either true labour or false labour.
• Your breasts may leak colostrum, the first form of breast milk.
• The foetus may drop into your pelvis in preparation for birth, a process known as lightening.
• Signs of labour can include contractions or losing your mucus plug.
• Varicose veins may develop when blood does not flow properly through the veins near the surface of your skin.
• You may find yourself needing to urinate more frequently and might experience leakage of urine when you cough or sneeze. Pelvic floor exercises can help with this.

In the third trimester, your baby gains weight and stores fat in preparation for birth. Their skin begins to smooth out, and they lose the fine layer of hair called lanugo.

During this period, your baby will remain active and continue to move around. By week 36, they typically turn into a head-down position, ready for delivery. In the final weeks, they often settle lower into your pelvis.

Month 8 (weeks 28 through 32)

In the third trimester, your baby gains weight and stores fat in preparation for birth. Their skin begins to smooth out, and they lose the fine layer of hair called lanugo.

During this period, your baby will remain active and continue to move around. By week 36, they typically turn into a head-down position, ready for delivery. In the final weeks, they often settle lower into your pelvis.

• Week 28: The foetus may start to turn head-down in preparation for birth. By the end of the seventh month, it is about 14 to 15 inches long and weighs between 2 and 3 pounds.
• Week 29: You may notice that the kicks and jabs feel more like gentle pokes now that the fetus is getting cramped in the amniotic sac.
• Week 30: The foetus can control its own body heat. Its brain is maturing and growing rapidly.
• Week 31: The foetus can process more information and stimuli. You may notice clearer patterns of when it is awake and when it is asleep.
• Week 32: The foetus’s skin is no longer translucent. Except for the lungs and brain, most other organs are well-formed and prepared for birth.

Your baby is growing rapidly, gaining approximately half a pound each week. The fetus is now about 17 to 18 inches long and weighs around 5 pounds. While your baby's bones are fully formed, they remain soft, and the lanugo (fine hair covering the body) has started to fall off.

Month 9 (weeks 33 through 36)

During this stage, the foetus continues to grow and mature. The lungs are nearly fully developed at this point in pregnancy. The ninth month primarily focuses on finalizing growth and brain development.

• Week 33: The foetus’s bones are hardening, except for the cranial bones surrounding its brain, which need to remain soft to pass through the birth canal.
• Week 34: The vernix that protects the Foetus’s skin starts to get thicker.
• Week 35: The Foetus’s brain continues to grow, but still only weighs two-thirds of what it should at birth.
• Week 36: The Foetus loses its lanugo, and it has hair on its head.

Your baby is approximately 16 to 19 inches long and weighs around 6 to 6½ pounds. As your baby’s body fat increases, they are growing larger and have less space to move. While their movements may be less forceful, you will still feel stretches and wiggles.

Month 10 (Weeks 37 through 40)

In this last month, labour could begin at any moment. By now, the position of the foetus may have shifted in preparation for delivery. Ideally, the foetus is positioned head-down in your uterus. You may experience significant discomfort during this final phase as the foetus descends into your pelvis in readiness for birth. Your healthcare provider might suggest that you track foetal movements through kick counts.

• Week 37: The foetus’s toenails reach the tips of its toes. You may start to feel the foetus dropping into your pelvis.
• Week 38: The foetus is packing on 0.5 pounds per week to get to its final size.
• Week 39: The foetus is at full term, and its organs are ready to function independently.
• Week 40: It’s your due date week. Call your midwife if you notice any signs of labour.

The foetus is now approximately 18 to 20 inches long and weighs between 7 to 9 pounds. As you approach your due date, your baby may shift into a head-down position in preparation for birth. Most babies present head down.

It can be alluring to begin counting down the days until your due date and wish for an early delivery, but it's essential to keep in mind that each week in this last phase of development is vital for your baby's readiness for birth. During the third trimester, the fetus quickly accumulates weight, adding body fat that will be advantageous after delivery.

For more information, you can also watch the Bupa.co.uk video below on the stages of pregnancy.

 Bupa: Stages of Pregnancy

Or visit the NHS UK website.

NHS UK: Pregnancy Week By Week