Weekly growth baby during pregnancy
Pregnancy stages week by week
Pregnancy stages week by week | BabyCenter- Community
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Looking for a week-by-week guide to pregnancy? You're in luck! We've got loads of expert-approved info about each week and trimester, including what's up with your growing baby and what changes to expect for yourself.
You'll find stunning fetal development videos, thousands of articles, and helpful tools like our Due Date Calculator and Baby Names Finder. Meet other parents-to-be in our online community, and get all of this and more in our free pregnancy app. Dive in, and congratulations!
First Trimester of Pregnancy
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Second Trimester of Pregnancy
Third Trimester of Pregnancy
Latest in pregnancy week by week
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Fetal development by week: Your baby in the womb
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From conception to labor, your baby is constantly growing and developing. Your baby moves through different stages, starting as a blastocyst, then maturing into an embryo, and then a fetus. Around the 5 week mark, cells in your baby's future heart will begin to flicker. At 27 weeks they'll have regular sleep and wake cycles, and at 39 weeks your baby is physically developed. Use this timeline to learn how big your baby is, plus how they're developing throughout pregnancy.
Follow your baby's development week by week, from conception to labor, in these amazingly detailed, doctor-reviewed images.
2 weeks: Fertilization
At the start of this week, you ovulate. Your egg is fertilized 12 to 24 hours later if a sperm penetrates it. Over the next several days, the fertilized egg will start dividing into multiple cells as it travels down the fallopian tube, enters your uterus, and starts to burrow into the uterine lining.
Read about fertilization.
3 weeks: Implantation
Now nestled in the nutrient-rich lining of your uterus is a microscopic ball of hundreds of rapidly multiplying cells that will develop into your baby.
This ball of cells, called a blastocyst, has begun to produce the pregnancy hormone hCG, which tells your ovaries to stop releasing eggs.
Read about implantation.
4 weeks
Your ball of cells is now officially an embryo. You're now about 4 weeks from the beginning of your last period. It's around this time – when your next period would normally be due – that you might be able to get a positive result on a home pregnancy test.
Your baby is the size of a poppy seed.
Read about your pregnancy at 4 weeks.
5 weeks
Your baby resembles a tadpole more than a human, but is growing fast. The circulatory system is beginning to form, and cells in the tiny "heart" will start to flicker this week.
Your baby is the size of a sesame seed.
Read about your pregnancy at 5 weeks.
6 weeks
Your baby's nose, mouth and ears are starting to take shape, and their intestines and brain are beginning to develop.
Your baby is the size of a lentil.
Read about your pregnancy at 6 weeks.
7 weeks
Your baby has doubled in size since last week, but still has a tail, which will soon disappear. Little hands and feet that look more like paddles are emerging from the developing arms and legs.
Your baby is the size of a blueberry.
Read about your pregnancy at 7 weeks.
8 weeks
Your baby has started moving around, though you won't feel your baby move yet. Nerve cells are branching out, forming primitive neural pathways. Breathing tubes now extend from their throat to their developing lungs.
Your baby is the size of a kidney bean.
Read about your pregnancy at 8 weeks.
9 weeks
Your baby's basic anatomy is developing (they even have tiny earlobes now), but there's much more to come. Their embryonic tail has disappeared and they weigh just a fraction of an ounce but are about to start gaining weight fast.
Your baby is the size of a grape.
Read about your pregnancy at 9 weeks.
10 weeks
Your embryo has completed the most critical portion of development. Their skin is still translucent, but their tiny limbs can bend and fine details like nails are starting to form.
Your baby is the size of a kumquat
Read about your pregnancy at 10 weeks.
11 weeks
Your baby is almost fully formed. They're kicking, stretching, and even hiccupping as their diaphragm develops, although you can't feel any activity yet.
Your baby is the size of a fig.
Read about your pregnancy at 11 weeks.
12 weeks
This week your baby's reflexes kick in: Their fingers will soon begin to open and close, toes will curl, and their mouth will make sucking movements.
Your baby is the size of a lime.
Read about your pregnancy at 12 weeks.
13 weeks
This is the last week of your first trimester. Your baby's tiny fingers now have fingerprints, and their veins and organs are clearly visible through their skin.
If you're having a girl, her ovaries contain more than 2 million eggs.
Your baby is the size of a pea pod.
Read about your pregnancy at 13 weeks.
Entering the second trimester: What lies ahead
In this illustration, you can see how big – and yet, how tiny still – your baby is as you begin your second trimester.
After the first trimester, a miscarriage is much less likely. And for many moms-to-be, early pregnancy symptoms like morning sickness and fatigue have faded away. If you're feeling more energetic now and haven't been exercising, it's a good time to start a regular pregnancy fitness routine.
Plus: See our ultimate pregnancy to-do list for the second trimester
14 weeks
Your baby's brain impulses have begun to fire and they're using their facial muscles. Their kidneys are working now, too. If you have an ultrasound, you may even see them sucking their thumb.
Your baby is the size of a lemon.
Read about your pregnancy at 14 weeks.
15 weeks
Your baby's eyelids are still fused shut, but they can sense light. If you shine a flashlight on your tummy, they'll move away from the beam. Ultrasounds done this week may reveal your baby's sex.
Your baby is the size of an apple.
Read about your pregnancy at 15 weeks.
16 weeks
The patterning on your baby's scalp has begun, though their hair isn't visible yet. Their legs are more developed, their head is more upright, and their ears are close to their final position.
Your baby is the size of an avocado.
Read about your pregnancy at 16 weeks.
17 weeks
Your baby can move their joints, and their skeleton – formerly soft cartilage – is now hardening to bone. The umbilical cord is growing stronger and thicker.
Your baby is the size of a turnip.
Read about your pregnancy at 17 weeks.
18 weeks
Your baby is flexing their arms and legs, and you may be able to feel those movements.
Internally, a protective coating of myelin is forming around their nerves.
Your baby is the size of a bell pepper.
Read about your pregnancy at 18 weeks.
19 weeks
Your baby's senses – smell, vision, touch, taste and hearing – are developing and they may be able to hear your voice. Talk, sing or read out loud to them, if you feel like it.
Your baby is the size of an heirloom tomato.
Read about your pregnancy at 19 weeks.
20 weeks
Your baby can swallow now and their digestive system is producing meconium, the dark, sticky goo that they'll pass in their first poop – either in their diaper or in the womb during delivery.
Your baby is the size of a banana.
Read about your pregnancy at 20 weeks.
21 weeks
Your baby's movements have gone from flutters to full-on kicks and jabs against the walls of your womb. You may start to notice patterns as you become more familiar with their activity.
Your baby is the size of a carrot.
Read about your pregnancy at 21 weeks.
22 weeks
Your baby now looks almost like a miniature newborn. Features such as lips and eyebrows are more distinct, but the pigment that will color their eyes isn't present yet.
Your baby is the size of a spaghetti squash.
Read about your pregnancy at 22 weeks.
23 weeks
Your baby's ears are getting better at picking up sounds. After birth, they may recognize some noises outside the womb that they're hearing inside now.
Your baby is the size of a large mango.
Read about your pregnancy at 23 weeks.
24 weeks
Your baby cuts a pretty long and lean figure, but chubbier times are coming. Their skin is still thin and translucent, but that will begin to change soon too.
Your baby is the size of an ear of corn.
Read about your pregnancy at 24 weeks.
25 weeks
Your baby's wrinkled skin is starting to fill out with baby fat, making them look more like a newborn.
Their hair is beginning to come in, and it has color and texture.
Your baby is now the same weight as an average rutabaga.
Read about your pregnancy at 25 weeks.
26 weeks
Your baby is now inhaling and exhaling amniotic fluid, which helps develop their lungs. These breathing movements are good practice for that first breath of air at birth.
Your baby is the size of a bunch of scallions.
Read about your pregnancy at 26 weeks.
27 weeks
This is the last week of your second trimester. Your baby now sleeps and wakes on a regular schedule, and their brain is very active. Their lungs aren't fully formed, but they could function outside the womb with medical help.
Your baby is the size of a head of cauliflower.
Read about your pregnancy at 27 weeks.
Entering the third trimester: What lies ahead
In this illustration, you'll notice that your growing baby takes up quite a bit of room these days. In the third trimester, you might be peeing more often or have leg cramps as they press on nerves in your hips and back.
Now's the time to do things like sign up for a childbirth class, choose a doctor for your baby, and create a baby registry, if you haven't done so already.
28 weeks
Your baby's eyesight is developing, which may enable them to sense light filtering in from the outside. They can blink, and their eyelashes have grown in.
Your baby is the size of a large eggplant.
Read about your pregnancy at 28 weeks.
29 weeks
Your baby's muscles and lungs are busy getting ready to function in the outside world, and their head is growing to make room for their developing brain.
Your baby is the size of a butternut squash.
Read about your pregnancy at 29 weeks.
30 weeks
Your baby is surrounded by a pint and a half of amniotic fluid, although there will be less of it as they grow and claim more space inside your uterus.
Your baby is the size of a large cabbage.
Read about your pregnancy at 30 weeks.
31 weeks
Your baby can now turn their head from side to side.
A protective layer of fat is accumulating under their skin, filling out their arms and legs.
Your baby is the size of a coconut.
Read about your pregnancy at 31 weeks.
32 weeks
You're probably gaining about a pound a week now. Half of that goes straight to your baby, who will gain one-third to half their birth weight in the next seven weeks in preparation for life outside the womb.
Your baby is the size of a large jicama.
Read about your pregnancy at 32 weeks.
33 weeks
The bones in your baby's skull aren't fused yet. That allows them to shift as their head squeezes through the birth canal. They won't fully fuse until adulthood.
Your baby is the size of a pineapple.
Read about your pregnancy at 33 weeks.
34 weeks
Your baby's central nervous system is maturing, as are their lungs. Babies born between 34 and 37 weeks who have no other health problems usually do well in the long run.
Your baby is the size of a cantaloupe.
Read about your pregnancy at 34 weeks.
35 weeks
It's getting snug inside your womb – but you should still feel your baby moving as much as ever. Your baby's kidneys are fully developed, and their liver can process some waste products.
Your baby is the size of a honeydew melon.
Read about your pregnancy at 35 weeks.
36 weeks
Your baby is gaining about an ounce a day. They're also losing most of their lanugo hair that covered their body, along with the vernix caseosa, a waxy substance that was protecting their skin until now.
Your baby is the size of a head of romaine lettuce.
Read about your pregnancy at 36 weeks.
37 weeks
Your due date is very close, and though your baby looks like a newborn, they're not considered full-term until 39 weeks. Over the next two weeks, their lungs and brain will continue to mature.
Your baby is the size of a bunch of Swiss chard.
Read about your pregnancy at 37 weeks.
38 weeks
Are you curious about your baby's eye color? Their irises aren't fully pigmented at birth, so their eyes could change color up until they're about a year old.
Your baby is the size of a leek.
Read about your pregnancy at 38 weeks.
Turning full term
At 39 weeks, your baby will be considered full-term. In the illustration, you can see the mucus plug sealing your uterus and how squished your intestines are now.
39 weeks
Your baby's physical development is complete, but they're still busy putting on fat and growing bigger.
Your baby is the size of a mini watermelon.
Read about your pregnancy at 39 weeks.
40 weeks
If you're past your due date, you may not be as late as you think, especially if you calculated it solely based on the day of your last period. Sometimes women ovulate later than expected.
Your provider will continuously assess your pregnancy to make sure you can safely continue your pregnancy.
Your baby is the size of a small pumpkin.
Read about your pregnancy at 40 weeks.
41 weeks
Your baby is now considered late-term. Going more than two weeks past your due date can put you and your baby at risk for complications, so your provider will probably talk to you about inducing labor. They may perform a non-stress test (NST) to monitor your baby's fetal heart rate and your contractions to make sure your baby isn't in any distress.
Read about your pregnancy at 41 weeks.
Labor and delivery
Meeting your baby for the first time is so exciting – but exactly what will lead up to that moment is unpredictable, and it's natural to feel nervous. Here's some help as you prepare for the big day. Find out how you'll know you're in labor and what to expect from delivery:
Learn the signs of labor and stages of labor
Read when to go to the hospital for labor
Take our free childbirth class
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Kate Marple
Kate Marple is a writer and editor who specializes in health, pregnancy, and parenting content.
She's passionate about translating complicated medical information into helpful pregnancy and parenting advice that's easy to understand. She lives in San Francisco with her family.
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Child development by weeks | Regional Perinatal Center
Expectant mothers are always curious about how the fetus develops at a time when it is awaited with such impatience.
Let's talk and look at the photos and pictures of how the fetus grows and develops week by week.
What does the puffer do for 9 whole months in mom's tummy? What does he feel, see and hear?
Let's start the story about the development of the fetus by weeks from the very beginning - from the moment of fertilization. A fetus up to 8 weeks old is called embryo , this occurs before the formation of all organ systems.
Embryo development: 1st week
The egg is fertilized and begins to actively split. The ovum travels to the uterus, getting rid of the membrane along the way.
On the 6th-8th days, implantation of eggs is carried out - implantation into the uterus. The egg settles on the surface of the uterine mucosa and, using the chorionic villi, attaches to the uterine mucosa.
Embryo development: 2-3 weeks
Picture of embryo development at 3 weeks.
The embryo is actively developing, starting to separate from the membranes.
At this stage, the beginnings of the muscular, skeletal and nervous systems are formed. Therefore, this period of pregnancy is considered important.
Embryo development: 4–7 weeks
Fetal development by week in pictures: week 4
Fetal development by week photo: week 4
Photo of an embryo before the 6th week of pregnancy.
The heart, head, arms, legs and tail are formed in the embryo :) . Gill slit is defined. The length of the embryo at the fifth week reaches 6 mm.
Fetal development by week photo: week 5
At the 7th week, the rudiments of the eyes, stomach and chest are determined, and fingers appear on the handles. The baby already has a sense organ - the vestibular apparatus. The length of the embryo is up to 12 mm.
Fetal development: 8th week
Fetal development by week photo: week 7-8
The face of the fetus can be identified, the mouth, nose, and auricles can be distinguished.
The head of the embryo is large and its length corresponds to the length of the body; the fetal body is formed. All significant, but not yet fully formed, elements of the baby's body already exist. The nervous system, muscles, skeleton continue to improve.
Fetal development in the photo already sensitive arms and legs: week 8
The fetus developed skin sensitivity in the mouth (preparation for the sucking reflex), and later in the face and palms.
At this stage of pregnancy, the genitals are already visible. Gill slits die. The fruit reaches 20 mm in length.
Fetal development: 9–10 weeks
Fetal development by week photo: week 9
Fingers and toes already with nails. The fetus begins to move in the pregnant woman's stomach, but the mother does not feel it yet. With a special stethoscope, you can hear the baby's heartbeat. Muscles continue to develop.
Weekly development of the fetus photo: week 10
The entire surface of the fetal body is sensitive and the baby develops tactile sensations with pleasure, touching his own body, the walls of the fetal bladder and the umbilical cord. It is very curious to observe this on ultrasound. By the way, the baby first moves away from the ultrasound sensor (of course, because it is cold and unusual!), And then puts his hands and heels trying to touch the sensor.
It's amazing when a mother puts her hand to her stomach, the baby tries to master the world and tries to touch with his pen "from the back".
The development of the fetus: 11–14 weeks
Development of the fetus in the photo of the legs: weeks 11
Hands, legs and eyelids are formed, and the genitals become distinguishable (you can find out the gender child). The fetus begins to swallow, and if something is not to its taste, for example, if something bitter got into the amniotic fluid (mother ate something), then the baby will begin to frown and stick out his tongue, making less swallowing movements.
Fruit skin appears translucent.
Development of the fetus: Week 12
Photo of the fetus 12 weeks per 3D ultrasound
buds are responsible for production for production urine. Blood forms inside the bones. And hairs begin to grow on the head. Moves more coordinated. The skin turns pink, the ears and other parts of the body, including the face, are already visible. Imagine, a child can already open his mouth and blink, as well as make grasping movements. The fetus begins to actively push in the mother's tummy. The sex of the fetus can be determined by ultrasound. Baby sucks his thumb, becomes more energetic. The auditory ossicles become stiff and now they are able to conduct sounds, the baby hears his mother - heartbeat, breathing, voice. The fetus intensively gains weight, fat deposits are formed. The weight of the fetus reaches 650 g, and the length is 300 mm. The lungs at this stage of fetal development are so developed that the baby can survive in the artificial conditions of the intensive care unit. Lungs continue to develop. Now the baby is already falling asleep and waking up. Downy hairs appear on the skin, the skin becomes wrinkled and covered with grease. The cartilage of the ears and nose is still soft. Lips and mouth become more sensitive. 9 out of 10 children born at this term survive. The lungs are now adapted to breathe normal air. Breathing is rhythmic and body temperature is controlled by the CNS. The baby can cry and responds to external sounds. Child opens eyes while awake and closes during sleep. The skin becomes thicker, smoother and pinkish. Starting from this period, the fetus will actively gain weight and grow rapidly. Almost all babies born prematurely at this time are viable. The weight of the fetus reaches 2500 g, and the length is 450 mm. The fetus reacts to a light source. The fetus is quite developed, prepared for birth and considered mature. The baby has mastered over 70 different reflex movements. Due to the subcutaneous fatty tissue, the baby's skin is pale pink. The head is covered with hairs up to 3 cm. The baby perfectly mastered the movements of his mother , knows when she is calm, excited, upset and reacts to this with her movements. During the intrauterine period, the fetus gets used to moving in space, which is why babies love it so much when they are carried in their arms or rolled in a stroller. For a baby, this is a completely natural state, so he will calm down and fall asleep when he is shaken. The nails protrude beyond the tips of the fingers, the cartilages of the ears and nose are elastic. After the birth, the baby longs for touching his body, because at first he cannot feel himself - the arms and legs do not obey the child as confidently as it was in the amniotic fluid. Therefore, so that your baby does not feel lonely, it is advisable to carry him in your arms, press him to you while stroking his body. And one more thing, the baby remembers the rhythm and sound of your heart very well . Therefore, you can comfort the baby in this way - take him in your arms, put him on the left side and your miracle will calm down, stop crying and fall asleep. And for you, finally, the time of bliss will come :) . Contents Swollen breasts, which are preparing for the upcoming lactation, are already quite large. Due to the high level of progesterone, the mammary glands become hypersensitive, sometimes a slight tingling may be felt. Normally, your discharge should be light in color, smooth and without a strong odor. If you notice that the smell of discharge has become sharp and unpleasant, as well as a change in color and consistency - this is a reason to immediately consult a doctor. If the discharge has become watery, this may indicate leakage of amniotic fluid. It is better to contact your gynecologist immediately. During this period, physical activity is undesirable.
Development of the fetus for weeks: Week 14 9000 9000 Fetal development: 15-18 weeks
Fetal development by weeks photo: week 15 Fetal development: 19-23 weeks
Fetal development by week photo: week 19 
Pseudo-feces are formed in the intestines of the fetus - meconium , kidneys begin to work. During this period, the brain develops very actively.
Fetal development by weeks photo: week 20 Fetal development: 24-27 weeks
Fetal development by week photo: week 27 
The eyes develop, open slightly and can perceive light and squint from direct sunlight. In girls, the labia majora do not yet cover the small ones, and in boys, the testicles have not yet descended into the scrotum. Fetal weight reaches 900–1200 g, and the length is 350 mm. Fetal development: 28-32 weeks
Fetal development: 33-37 weeks
Fetal development by week photo: week 36 
Muscle tone increases and the baby can turn and raise his head. On which, the hairs become silky. The child develops a grasping reflex. The lungs are fully developed. Fetal development: 38-42 weeks
Fetal development by weeks photo: week 40 
In boys, the testicles have descended into the scrotum, and in girls, the large labia cover the small ones. The weight of the fetus reaches 3200-3600 g, and the length is 480-520 mm. 30 weeks of pregnancy what happens to the fetus
What happens to the baby at 30 weeks?
The growth of the fetus at this point reaches 38 cm, and the weight ranges from 1300-1500 grams. Such sizes do not allow the child to actively move. Now he more and more often makes himself felt with the help of pushes with arms or legs. Mom should strictly monitor the movements of the baby, if their frequency or nature has changed, you should immediately consult a doctor. What happens to the mother at 30 weeks pregnant?
Make sure your chest is comfortable. Choose underwear that does not restrict your movements.
Recommendations for a future mother
