Skip to content Skip to sidebar Skip to footer

How your fetus grows during pregnancy: Stages, shape, size and what to expect

Staring at the positive pregnancy test?? Is your heart racing?? The feeling that life is going to change completely and a mixed bag of emotions with excitement and nervousness, is unexplainable. Well, Congratulation mommy-to-be!! Your baby is growing and soon you’ll see your belly growing too!!

Ready to share the announcement with the rest of the world with your growing belly???

From a small bump to a basketball, all pregnant bellies come in different shapes, and sizes. All women are different, so the pregnant will be unique for all you mothers out there. Let’s guide you through the tidal wave of emotions and physical changes that you are about to experience for yourself and your baby.

First-trimester baby development: What to expect??

The first trimester spans from the day of conception up to 12 weeks. This includes the first three months of your pregnancy. During this time of the trimester, your will be changing frequently from a tiny cluster of cells to a fetus that has the features of a human baby. You may not see any noticeable change in the shape and size of your belly, but you’ll surely feel like you’re pregnant even if you aren’t showing yet!

Month 1

Week 1: Your pregnancy begins from the first day of your last period which is your week 1.

Week 2-4: At this time, the egg has been fertilized and implants into the uterine lining, and a sac grows around it. This sac is called as the amniotic sac and holds the amniotic fluid and cushions the embryo. In these weeks, the placenta is also formed which provides nutrition and support to the baby from the mother and transfers wastes from the baby. In the first few weeks of pregnancy, the face will form and eyes begin to develop, and the tiny heart begins to beat. The mouth, throat, and jaw are also developing.

By the end of the 4th week, your baby will be around 1/4th inch, smaller than a grain of rice!

B vitamins play an important role in you and your baby’s overall development and your health during pregnancy. Vitamin B6 and Folic Acid are equally important for early development, so make sure you are taking them every day on time and not skipping them.

Month 2

Week 5-9: though your baby is still too tiny, but they are growing at a rapid pace. At this time, your baby’s facial features are continuously developing. A little fold of skin of the ear begins to form at both sides of the head. Tiny buds have started to form that eventually grow into arms and legs. Fingers, toes, and eyes have also started forming. The brain, spinal cord, and other neural tissue of the central nervous system are formed well by now. The baby’s digestive tract and sensory organs have begun developing. The bone has started replacing the cartilage. At this point in time, your baby’s head is large in size compared to the rest of its body. Your baby’s heartbeat can be heard at about 6 weeks and after the 8th week, your baby is now called a fetus.

At the end of the second month, your baby is almost 1 inch long and weighs about 1/30 of an ounce.

Month 3

Week 10-13: The little limbs, hands, feet, fingers, and toes, are well developed by now. The fingernails and toenails also begin to form. The external ears and teeth begin to develop too. The baby has started developing the reproductive organs also but, they can’t yet be determined on an ultrasound or sonogram. At the end of the 3rd month, your baby is fully developed, with all organs and extremities present, weighs about an ounce, and is 4 inches long!

After the 3rd month of development, the chances of miscarriage drop significantly.

Second-trimester baby development: What to expect??

The second trimester of pregnancy is the time when most of women feel very comfortable. By this time, the first trimester symptoms mostly ease up or disappear, and you’re belly has not grown so big yet, so it’s comfortable to move around.

This is the trimester when you really get to enjoy your pregnancy!

Month 4

Week 14-17: In these weeks, hair, eyelids, eyelashes, and nails are well developed. You can now clearly listen to your baby’s heartbeat. The teeth now start becoming denser, and the baby begins to stretch, yawn, suck their thumb, yawn, and make super cute faces. The reproductive organs are now visible on an ultrasound. This is the month when your baby’s nervous system starts developing. By the end of the 4th month, your baby is about 6 inches long and weighs 4 ounces!

Month 5

Week 18-21: At this time, you may start feeling that your baby is moving, as your baby is developing muscles and exercising them. This first movement may feel like a flutter. Hair starts growing on the baby’s head and your baby’s shoulders, back, and temples are covered by a soft fine hair called as lanugo. This hair protects your baby and gets shed at the end of the baby’s first-week post-birth. The baby’s skin is covered with a whitish coating called vernix caseosa and this “cheesy” substance protects your baby’s skin from long exposure to the amniotic fluid. This coating gets shed just before birth.

By the end of the fifth month, your baby is about 10 inches long and weighs from 1/2 to 1 pound.

Month 6

Week 22-25: During the 6th month, your baby’s skin appears reddish in color, wrinkled and veins are visible through the baby’s translucent skin. Baby’s finger and toe prints are visible and developed. At this time, the eyelids begin to part and the eyes open. Baby responds to sounds by moving or increasing the pulse. You may notice jerking motions if the baby hiccups.

At the end of 6th month, your baby is about 12 inches long and weighs about 2 pounds.

Third-trimester baby development: What to expect??

Your belly is now growing more and more, your body is stretching and is probably feeling the effects of it! Grow baby, grow! Your excitement and anticipation are at their peak, along with the size of your belly. During the third trimester, you will experience a lot of change. There’s not much room left in your belly by now and your baby is pushing against your bladder and lungs. You may be very excited to start the countdown till your due date and hope that it comes early, but each week of this trimester helps your baby prepare for childbirth.

Month 7

Week 26-29: During this month, your baby will continue to grow and develop the existing organs and systems. In addition, a layer of fat will begin to be stored. At this stage, hearing is fully developed. He or she will react to sound, pain, and light and often changes position. The amount of amniotic fluid that cushions the baby begins to decrease as the baby grows larger. At the end of this month, your baby is about 14 inches long and can weigh between 2 – 4 lbs!

If born prematurely after week 27, your baby has a better chance of survival.

Month 8

Week 29-32: Your baby is continuing to mature and is developing reserves of body fat. At this stage, you may notice too many baby kicks. The baby’s brain is also developing rapidly and your baby can now see and hear. Almost all internal systems are well developed by now, but the lungs may still be not fully developed.

Your baby is about 18 inches long and weighs as much as 5 pounds.

Month 9

Week 33-36: Your baby continues to grow and mature. The lungs are now close to being fully developed. Your baby’s reflexes are coordinated so they can now blink, close their eyes, turn their head, grasp firmly, and respond to sounds, light, and touch.

Your baby is about 17 to 19 inches long and weighs from 5 ½ pounds to 6 ½ pounds.

Month 10

Week 37-40: These are the final weeks of pregnancy and you could go into labor at any moment. You may feel lesser movements at this time, but there’s nothing to worry about, that is because the baby doesn’t have any space left. During these weeks, the baby’s position will be changed to head down in your uterus to prepare for birth. In this final span of time, you may get very much uncomfortable as the baby drops down into your pelvis and prepares for birth.

Your baby is ready to enter this world now!!!

Your baby is about 18 to 20 inches long and weighs about 7 pounds.

Pregnancy is such an unforgettable and exciting time for mother and baby!! Maintaining a healthy, balanced diet, getting rest, being physically active, and avoiding stress are very important for you and your baby. We hope the information in this post has given you some good piece of information into the next few weeks of your new life with your baby. It’s still a long way to go on this exciting rollercoaster ride, so be gentle and calm with yourself, consult your doctor for any queries and do what’s right for you and your baby throughout your pregnancy.