This is the final part of your pregnancy. You may be tempted to start the countdown till your due date and hope that it would come early, but each week of this final stage of development helps your baby prepare for childbirth. Throughout the third trimester, your baby will gain weight quickly, adding body fat that will help after birth.
Remember, even though popular culture only mentions nine months of pregnancy, you may actually be pregnant for 10 months. The typical, full-term pregnancy is 40 weeks, which can take you into a tenth month. It’s also possible that you can go past your due date by a week or two (41 or 42 weeks). Your healthcare provider will monitor you closely as you approach your due date. If you pass your due date, and don’t go into spontaneous labor, your provider may induce you. This means that medications will be used to make you go into labor and have the baby. Make sure to talk to your healthcare provider during this trimester about your birth plan.
Month 8 (weeks 29 through 32)
Your baby will continue to mature and develop reserves of body fat. You may notice that your baby is kicking more. Baby's brain is developing rapidly at this time, and your baby can see and hear. Most internal systems are well developed, but the lungs may still be immature.
Your baby is about 46 cm long and weighs as much as 2.3 kg.
Month 9 (weeks 33 through 36)
During this stage, your baby will continue to grow and mature. The lungs are close to being fully developed at this point.
Your baby's reflexes are coordinated so he or she can blink, close the eyes, turn the head, grasp firmly, and respond to sounds, light, and touch.
Your baby is about 43 to 48 cm long and weighs from 2.5 kg to 3 kg.
Month 10 (Weeks 37 through 40)
In this final month, you could go into labor at any time. You may notice that your baby moves less due to tight space. At this point, your baby’s position may have changed to prepare for birth. Ideally, the baby is head down in your uterus. You may feel very uncomfortable in this final stretch of time as the baby drops down into your pelvis and prepares for birth.
Your baby is ready to meet the world at this point.
Your baby is about 46 to 51 cm long and weighs about 3 kgs.
Reference: @Cleveland Clinic medical professional.