Pregnancy Week by Week - Understanding Your Baby's Growth

Congratulations on embarking on this remarkable journey of pregnancy! Your body is now nurturing and shaping a little life within. As you patiently wait to hold your precious bundle, tracking the growth and development of your pregnancy week by week can be an exhilarating and informative experience.

Visualizing these changes through the comparison of your baby’s size to various fruits adds an extra touch of wonder and excitement to this beautiful process. Let’s explore each stage in detail, marvelling at how your tiny seed blossoms into ripe fruit over the course of weeks.

First Trimester of Pregnancy

Pregnancy Week by Week: (1 - 4 weeks) Conception to Plum-sized Embryo

During these initial weeks, your baby is a tiny cluster of cells, comparable in size to a plum seed. Crucial developments such as the formation of the neural tube take place, laying the foundation for your baby’s growth.

1 Week Pregnant: Conception and early signs of pregnancy

Week 1 of pregnancy is the magical moment when a tiny zygote starts its incredible journey towards becoming a bundle of joy. Though you may not feel it yet, your body is working its amazing magic to create new life. The signs may be subtle, like some mild cramping or spotting, but this is the beginning of something truly special. It’s mind-blowing to think that in just a few days, the stage will be set for your little one’s home for the next nine months. It’s an awe-inspiring time when every little change is laying the foundation for what’s to come.

How Big is my Baby at 1 week?

At 1 week, your baby is just a single cell, too small to be measured by traditional means.
How Big is my Baby at 2 weeks?

At 2 weeks, your baby is still microscopic, measuring just a fraction of a millimeter.
How Big is my Baby at 3 weeks?

At 3 weeks, your baby is still very small, similar in size to a grain of sugar.
How Big is my Baby at 4 weeks?

At 4 weeks, your baby is about the size of a poppy seed. They are approximately 0.04 inches (1 mm) long. During this time, the fertilized egg implants in the uterine lining, and the process of cell division begins, setting the stage for your baby’s development.

4 Weeks Pregnant: Confirmation of pregnancy and first prenatal visit

Congratulations on this exciting moment in your life! The 4th week of pregnancy marks the beginning of a beautiful journey into parenthood. It’s time to take the next step and schedule your first prenatal visit with a healthcare provider. This visit is crucial for creating a personalized care plan and addressing any questions or concerns you may have. You’ll discuss important topics like your medical history, symptoms, nutrition, exercise, and what to expect in the coming months. Get ready to kickstart a healthy and fulfilling pregnancy journey!

Pregnancy Week by Week (5-8 weeks): Blueberry to Raspberry-sized Embryo

By week eight, your baby has grown to about the size of a raspberry. Their heart is beating, and essential organs are beginning to form, marking a period of rapid growth and development.

How Big is my Baby at 5 weeks?

At 5 weeks, your baby is approximately the size of a sesame seed.
How Big is my Baby at 6 weeks?

At 6 weeks, your baby is about the size of a lentil, measuring roughly 0.2 inches (5 mm) in length.
How Big is my Baby at 7 weeks?

At 7 weeks, your baby is about the size of a blueberry, measuring approximately 0.3 inches (7 mm) long.
How Big is my Baby at 8 weeks?

At 8 weeks, your baby is about the size of a kidney bean. They measure approximately 0.6 inches (1.5 cm) in length and weigh around 0.04 ounces (1 gram). During this time, their facial features start to take shape, and tiny buds form that will become arms and legs.

8 Weeks Pregnant: Baby's development and common symptoms for the mother

Week 8 marks an exciting time for both the baby and the mother. The baby’s development is progressing rapidly, with fingers, toes, and facial features taking shape. Tiny fingernails and hair follicles are beginning to form. Meanwhile, the mother may experience symptoms like morning sickness, fatigue, breast changes, and mood swings due to hormonal shifts. It’s important for her to take care of her physical and emotional well-being and consult her healthcare provider as needed.

Pregnancy Week by Week (9-12 weeks): Lime to Plum-sized Fetus

Transitioning into the fetal stage, your baby is now the size of a plum. Facial features become more distinct, and limbs start to elongate, showcasing the remarkable progress your baby is making.

How Big is my Baby at 9 weeks?

At 9 weeks, your baby is about the size of a cherry, measuring roughly 0.9 inches (2.3 cm) in length.
How Big is my Baby at 10 weeks?

At 10 weeks, your baby is about the size of a strawberry, measuring approximately 1.2 inches (3 cm) long.
How Big is my Baby at 11 weeks?

At 11 weeks, your baby is about the size of a lime, measuring roughly 1.6 inches (4 cm) from crown to rump.
How Big is my Baby at 12 weeks?

At 12 weeks, your baby is approximately the size of a plum. They measure about 2.5 inches (6.3 cm) in length and weigh around half an ounce (14 grams). During this time, your baby’s facial features become more defined, with eyes moving closer together and ears shifting to their final position. Their tiny fingers and toes are also forming, and they may even begin to make small movements, although these won’t be felt by you just yet.

12 Weeks Pregnant: Completion of the First Trimester and Fetal Development

Entering the 12th week of pregnancy is a major milestone for expectant mothers. At this stage, the baby has evolved from an embryo to a fetus, measuring around 2.5 inches and weighing about half an ounce. The facial features are taking shape, and the little one is developing its own fingerprints! Inside the womb, key organs like the liver and kidneys are already active, while bone marrow kicks in to boost the immune system with white blood cells.

Furthermore, reproductive organs are forming, though it might still be too early to predict gender via ultrasound. However, there are breakthrough advances in gender determination through blood tests that allow gender prediction as early as 7 weeks. On a more personal note, moms-to-be may start feeling a surge of energy as early pregnancy symptoms like nausea and fatigue subside. It’s an exciting time as both mother and baby continue on this incredible journey together!

Pregnancy Week by Week (13-16 weeks): Peach to Avocado-sized Fetus

Continuing to grow steadily, your baby progresses from the size of a peach to an avocado. They become more active, and their senses start to develop, setting the stage for further exploration in the womb.

13 Weeks Pregnant: Beginnings of the second trimester and noticeable baby bump

Week 13 of pregnancy is a special time for moms-to-be! It’s often referred to as the “honeymoon phase” because many women start to feel a welcome relief from earlier symptoms like nausea and fatigue. With their energy levels rising, they might even notice a tiny baby bump starting to show as their body prepares to welcome the new arrival.

But the best part? This is when many expectant mothers experience the magical moment of feeling their baby’s first movements. It’s an emotional and physical milestone that makes the pregnancy journey even more real.

Remember, even during this exciting time, it’s important to keep up with regular prenatal care and self-care. Taking care of yourself means taking care of your little one too!

How Big is my Baby at 13 weeks?

At 13 weeks, your baby is about the size of a jalapeño, measuring approximately 2.9 inches (7.4 cm) long.

Second Trimester of Pregnancy

The second trimester of pregnancy, from weeks 13 to 27, is a special time for expectant mothers. It’s when energy levels rise, nausea and fatigue subside, and the baby’s development accelerates. Mothers can feel the baby’s first kicks, find out the gender through ultrasound, and bond with their child. This phase brings anticipation and excitement as parenthood becomes more real, requiring important check-ups and preparations for the baby’s arrival.

How Big is my Baby at 14 weeks?

At 14 weeks, your baby is about the size of a lemon, measuring roughly 3.4 inches (8.7 cm) long.
How Big is my Baby at 15 weeks?

At 15 weeks, your baby is about the size of an apple, measuring approximately 4 inches (10 cm) from crown to rump.
How Big is my Baby at 16 weeks?

At 16 weeks, your baby is about the size of an avocado. They measure approximately 4.6 inches (11.6 cm) in length and weigh around 3.5 ounces (100 grams). During this time, your baby’s movements become more coordinated, and they may even start sucking their thumb.

16 Weeks Pregnant: Feeling baby's movements and prenatal testing options

Experience the magic of feeling your baby’s first movements at Week 16. These flutters and kicks create a special bond between expectant parents and their little ones. It’s also the time to consider prenatal testing options like amniocentesis, CVS, ultrasound, and blood tests to ensure the baby’s health and well-being. Discuss these options with your healthcare provider to make informed decisions for your family.

Pregnancy Week by Week (17-20 weeks): Pomegranate to Banana-sized Fetus

By week 20, your baby is about the size of a banana. Their movements become more pronounced, and you may start feeling those first flutters as they stretch and flex their limbs.

How Big is my Baby at 17 weeks?

At 17 weeks, your baby is about the size of a turnip, measuring roughly 5.1 inches (13 cm) long.
How Big is my Baby at 18 weeks?

At 18 weeks, your baby is about the size of a bell pepper, measuring approximately 5.6 inches (14.2 cm) long.
How Big is my Baby at 19 weeks?

At 19 weeks, your baby is about the size of a tomato, measuring roughly 6 inches (15.3 cm) from crown to rump.
How Big is my Baby at 20 weeks?

At 20 weeks, your baby is approximately the size of a banana. They measure about 6.5 inches (16.5 cm) in length and weigh around 10.6 ounces (300 grams). This marks the halfway point of your pregnancy, and your baby’s organs are continuing to develop, with their heartbeat becoming stronger and more regular.

20 Weeks Pregnant: Anatomy scan and halfway point of pregnancy

Congratulations! You’ve reached the halfway point of your pregnancy journey, and it’s time for the much-anticipated anatomy scan. This detailed ultrasound not only gives you a closer look at your baby’s development but also provides vital information about their health. It’s an emotional and exciting moment for you and your partner as you get to see your little one in more detail – and maybe even find out their gender if you’re curious. The scan also offers reassurance and a chance to celebrate this significant milestone. As you reflect on the journey so far, there’s a sense of accomplishment, anticipation, and optimism about the future with your new arrival on the way. Exciting times lie ahead!

Pregnancy Week by Week (21-24 weeks): Papaya to Grapefruit-sized Fetus

As your baby reaches the size of a grapefruit, their senses continue to develop, and they can now hear sounds from the outside world, including your voice, fostering a bond between you and your little one.

How Big is my Baby at 21 weeks?

At 21 weeks, your baby is about the size of a carrot, measuring approximately 10.5 inches (26.7 cm) long.
How Big is my Baby at 22 weeks?

At 22 weeks, your baby is about the size of a papaya, measuring roughly 10.9 inches (27.8 cm) long.
How Big is my Baby at 23 weeks?

At 23 weeks, your baby is about the size of a grapefruit, measuring approximately 11.4 inches (28.9 cm) from crown to rump.
How Big is my Baby at 24 weeks?

At 24 weeks, your baby is approximately as long as an ear of corn. They measure about 8.5 inches (21.6 cm) in length and weigh around 1.5 pounds (680 grams). Their skin is becoming less transparent, and they’re developing more fat, providing insulation to regulate their body temperature.

24 Weeks Pregnant: Viability of the baby and increased Prenatal appointments

Welcome to a pivotal moment in your pregnancy journey! As you enter week 24, you’ll be pleased to know that your little one has reached the significant milestone of viability. It’s a heartwarming reassurance for parents-to-be, signalling that their baby’s chances of surviving if born prematurely are increasing.

As such, your prenatal appointments take on an even greater significance. Your healthcare providers will be closely monitoring your baby’s growth and development, ensuring they’re flourishing as they should. You may find yourself attending more frequent appointments, granting your healthcare team the opportunity to keep a watchful eye on your baby’s progress and address any potential concerns promptly.

These appointments may also involve more frequent ultrasounds and tests to ensure that your baby continues to develop well. It’s a time of attentive observation and preparation for the arrival of your little one.

Pregnancy Week by Week (25-28 weeks): Cauliflower to Eggplant-sized Fetus

With each passing week, your baby gains more weight and begins to fill out, reaching the size of an eggplant. Their lungs mature further in preparation for breathing air after birth.

How Big is my Baby at 25 weeks?

At 25 weeks, your baby is about the size of a squash, measuring roughly 13.6 inches (34.6 cm) long
How Big is my Baby at 26 weeks?

At 26 weeks, your baby is about the size of a scallion, measuring approximately 14 inches (35.6 cm) long.
How Big is my Baby at 27 weeks?

At 27 weeks, your baby is about the size of a cauliflower, measuring roughly 14.4 inches (36.6 cm) from crown to rump.

Third Trimester of Pregnancy

In the final trimester, from weeks 28 to 40, anticipation and preparation for the baby’s arrival intensify. The baby grows rapidly, reaching a viable stage. Physical discomforts like backaches and increased urination may occur due to the growing uterus. It’s important for the mother to attend regular checkups, maintain a healthy lifestyle, and prepare for labor through classes and a birth plan. This phase is crucial for both the mother’s well-being and the baby’s development.

28 Weeks Pregnant: Third Trimester begins and Countdown to Labor starts

Welcome to the exciting journey of week 28 in your pregnancy! As you enter the third trimester, anticipation for the arrival of your little one grows. It’s a great time to dive into childbirth classes, explore pain relief options, and lay out a birth plan. Don’t forget to start packing your hospital bag with all the essentials for both you and your baby.

Your body is working hard as your baby continues to develop. You might be feeling some discomfort like backaches, frequent trips to the bathroom, and difficulty sleeping. Remember, it’s essential to keep the lines of communication open with your healthcare provider about any worries or symptoms that pop up during this phase.

Taking care of yourself becomes even more crucial now. Please make sure you’re taking your prenatal vitamins, staying active with safe exercises, and eating well to prepare for labor. It’s also a great time to solidify plans for maternity leave and childcare while beginning discussions on baby names.

As the due date draws near, it’s common to experience a mix of emotions – from excitement to nervousness. But by getting ready and being well-informed, you can ease some of those anxieties. Here’s to this incredible journey towards bringing new life into the world!

How Big is my Baby at 28 weeks?

At 28 weeks, your baby is about the size of an eggplant. They measure approximately 14.8 inches (37.6 cm) in length and weigh around 2.2 pounds (1 kg). Your baby’s eyes can now open and close, and they’re beginning to distinguish between light and dark.

Pregnancy Week by Week (29-32 weeks): Squash to Coconut-sized Fetus

Your baby is now the size of a coconut, and their movements may become more restricted as they grow. It’s essential to monitor their movements and contact your healthcare provider if you notice any significant changes.

How Big is my Baby at 29 weeks?

At 29 weeks, your baby is about the size of a butternut squash, measuring roughly 15.2 inches (38.6 cm) long.
How Big is my Baby at 30 weeks?

At 30 weeks, your baby is about the size of a large cabbage, measuring approximately 15.7 inches (39.9 cm) long.
How Big is my Baby at 31 weeks?

At 31 weeks, your baby is about the size of a coconut, measuring roughly 16.2 inches (41.1 cm) from crown to rump.
How Big is my Baby at 32 weeks?

At 32 weeks, your baby is approximately the size of a squash. They measure about 16.7 inches (42.4 cm) in length and weigh around 3.8 pounds (1.7 kg). Your baby’s bones are hardening, and they’re gaining more fat, making their appearance rounder.

32 Weeks Pregnant: Baby's Significant Growth. Preparing for childbirth.

Week 32 of pregnancy is an exciting time as your little one keeps growing and developing! Imagine, they’re already about 16.7 inches long and tipping the scale at around 4 pounds. Even though their lungs are still getting ready for the big debut, they’re practicing those adorable breathing movements.

As you take care of yourself by eating well, staying hydrated, and getting plenty of rest, it’s also a great opportunity to get ready for childbirth. Consider diving into prenatal classes, creating that birth plan you’ve been dreaming about, and having a chat with your healthcare provider about pain relief options.

And don’t forget to pack your hospital bag with all the essentials for both you and your baby – it’s never too early to be prepared! Plus, as your due date draws near, arranging transportation to the hospital or birthing center would be a smart move. So soak in this special time of preparation and excitement as you count down the days until your little one arrives!

Pregnancy Week by Week (33-36 weeks: Pineapple to Honeydew-sized Fetus

Approaching the final weeks of pregnancy, your baby is the size of a honeydew melon. They continue to gain weight and prepare for birth, settling into the optimal position for delivery.

How Big is my Baby at 33 weeks?

At 33 weeks, your baby is about the size of a pineapple, measuring approximately 17.2 inches (43.7 cm) long.
How Big is my Baby at 34 weeks?

At 34 weeks, your baby is about the size of a cantaloupe, measuring roughly 17.7 inches (45 cm) long.
How Big is my Baby at 35 weeks?

At 35 weeks, your baby is about the size of a honeydew melon, measuring approximately 18.2 inches (46.2 cm) from crown to rump.
How Big is my Baby at 36 weeks?

At 36 weeks, your baby is approximately the size of the head of a romaine lettuce. They measure about 18.7 inches (47.4 cm) in length and weigh around 5.8 pounds (2.6 kg). Most of their major organs are fully developed, and they’re practicing breathing by inhaling and exhaling amniotic fluid.

36 Weeks Pregnant: Baby Getting into position and Signs of labor approaching

As you reach week 36 of your pregnancy, your little one is likely getting into position for their big debut! With the baby’s head in the downward “vertex” position, it’s all systems go for delivery day. You might start feeling some extra pressure in your pelvic area as your baby gets cozy in your pelvis. This is what they call “lightening”, and it’s a clear sign that your body is gearing up for labor. But that’s not all – as you get closer to the big day, be on the lookout for more Braxton Hicks contractions, a burst of energy known as the “nesting instinct,” and an uptick in vaginal discharge.

Staying connected with your healthcare provider at this stage is crucial. Keep an eye out for any changes or symptoms that could signal the start of labor. It’s also a great time to go over your birth plan and ensure everything is set for when the moment arrives.

Pregnancy Week by Week (37-40 weeks): Watermelon-sized Baby

Congratulations, you’ve reached full term! Your baby is now the size of a watermelon and ready to meet you. The countdown to your baby’s arrival begins, and soon, you’ll hold your precious bundle of joy in your arms.

How Big is my Baby at 37 weeks?

At 37 weeks, your baby is about the size of a Swiss chard, measuring approximately 19.1 inches (48.5 cm) long.
How Big is my Baby at 38 weeks?

At 38 weeks, your baby is the length of a stalk of rhubarb. They measure about 19.6 to 20.9 inches (50 to 53 cm) in length and weigh around 6.2 to 9.2 pounds (2.8 to 4.2 kg). Your baby’s lungs are fully matured, and they’re ready for life outside the womb.
How Big is my Baby at 39 weeks?

At 39 weeks, your baby is about the size of a pumpkin, measuring roughly 20.2 inches (51.2 cm) long.
How Big is my Baby at 40 weeks?

At 40 weeks, your baby is about the size of a watermelon, measuring approximately 20.7 inches (52.6 cm) from crown to heel.

40 Weeks Pregnant: Due date and Waiting for the Arrival of the Baby

As the big due date in week 40 approaches, the excitement and anticipation of meeting your new little bundle of joy are growing by the day. But let’s face it – there’s also a tinge of nervousness and uncertainty in the air. We know that due dates are just estimates, and babies often have their own schedules. The waiting game can be a rollercoaster of emotions for expectant parents, filled with both excitement and jitters as they eagerly await the start of labor.
It’s a time of preparing for the unknown, making sure everything is set for the baby’s arrival, and trying to stay as calm and patient as possible. And it’s not just you; your family and friends are right there with you, sending good vibes and checking in regularly to see if there’s any news about the little one.

The waiting game may bring on a mix of feelings, but it’s all part of the incredible journey toward welcoming your new family member into the world.

Conclusion

Keeping track of your pregnancy week by week is more than just a routine – it’s a way for you to connect with your baby’s growth and take control of your own well-being. By staying informed about the changes in your body, you can make sure that you and your baby are on the right track. Plus, it gives you peace of mind knowing that any potential issues can be addressed early on.
But let’s face it – pregnancy can be overwhelming. That’s why having a support network is crucial. Your healthcare provider, loved ones, and even other moms-to-be can offer the emotional and practical help you need every step of the way.

And here’s the good news: there are plenty of resources out there to guide you through this journey. From online forums to pregnancy apps and community groups, you’ll find a wealth of insights, advice, and comfort from others who understand what you’re going through.

So don’t miss out on these valuable resources – they’re here to ensure that you have the knowledge and support for a healthy and positive pregnancy experience. You’ve got this!

Learn more about the childbirth in our blog – Stages and Phases of Childbirth

REFERENCES

Baby Center – Pregnancy Week by Week

Your Pregnancy Week-by-Week

How Big is my Baby during Pregnancy?

How big is my baby? Week-by-week fruit and veggie comparisons

How Big Is My Baby This Week? Here’s a Baby Fruit Size Chart

The Bump – Pregnancy Week by Week

Written by: Donna Costa