How big is my baby this week? Baby size development week by week during pregnancy is a fantastic miracle! But understanding what size a baby really is just by reading about grams, oz, millimeters, or inches is difficult. Check out this baby size chart by fruits and vegetables instead! This is a perfect way of envisioning your growing baby!
Below the chart, you’ll find descriptions of each pregnancy week and what’s going on with your baby this week.
1 Week Pregnant
Menstruation and disappointment. But the 1st week of pregnancy, if you conceive! Needless to say, your baby has no size or weight yet, but despite being on your period, your body is already preparing for becoming pregnant.
Read more about the first week of pregnancy here.
2 Weeks Pregnant
Being 2 weeks pregnant means almost being pregnant, well, hopefully! This is a good time to really read up on the essential ovulation symptoms and how to maximize your chances of conceiving!
Read all about being 2 weeks pregnant here.
3 Weeks Pregnant
3 weeks pregnant means finally actually being pregnant. Conception occurs, yay! (But it is too early for a positive pregnancy test.)
Read all about being 3 weeks pregnant here.
4 Weeks Pregnant
At 4 weeks pregnant, many women will receive a positive pregnancy test result. A lot is happening with the embryo this week. The blastocyst (early-stage embryo) implants in the uterus.
Baby size: A poppy seed
Baby length: About 0.014 to 0.04 inches (0.4-1 mm)
Baby weight: Almost none
Read all about being 4 weeks pregnant here.
5 Weeks Pregnant
5 weeks pregnant, the embryo’s heart is developing rapidly. You may see a positive pregnancy test.
Baby size: A peppercorn or sesame seed
Baby length: About 0.05 inches (1.5 mm)
Baby weight: Less than 0.04 oz (1 gram)
Read all about being 5 weeks pregnant here.
6 Weeks Pregnant
Your baby is tiny but growing fast. The heart is beating!
Baby size: A pomegranate seed
Baby length: About 0.13 inches (3.3 mm)
Baby weight: Less than 0.04 oz (1 gram)
Read all about being 6 weeks pregnant here.
7 Weeks Pregnant
Your baby is slowly starting to look human, and the brain is expanding rapidly.
Baby size: A blueberry
Baby length: About 0.5 inches (13 mm)
Baby weight: Less than 0.04 oz (1 gram)
Read all about being 7 weeks pregnant here.
8 Weeks Pregnant
At 8 weeks pregnant, it’s possible to measure brain activity for your embryo. Already!
Baby size: A raspberry
Baby length: About 0.63 inches (16 mm)
Baby weight: 0.04 oz (1 gram)
Read all about being 8 weeks pregnant here.
9 Weeks Pregnant
Cool – your baby’s embryonic tail is now gone! Fetal development is going fast when you are 9 weeks pregnant.
Baby size: A cherry
Baby length: About 0.9 inches (23 mm)
Baby weight: Less than 0.07 oz (2 grams)
Read all about being 9 weeks pregnant here.
10 Weeks Pregnant
Even though your baby is still tiny, they already look like a baby in many ways and act like a baby, too! Your uterus has now become a playground. Your baby has begun to move, kicking and waving more than you can imagine.
Baby size: A lime
Baby length: About 1.22 inches (31 mm)
Baby weight: About 0.14 oz (4 grams)
Read all about being 10 weeks pregnant here.
11 Weeks Pregnant
Your baby’s toes and fingers have now separated, and the webbed look they once had is gone.
Baby size: A fig
Baby length: About 1.61 inches (41 mm)
Baby weight: About 0.25 oz (7 grams)
Read all about being 11 weeks pregnant here.
12 Weeks Pregnant
At 12 weeks, your baby looks like a little human. The eyes, ears, and nose are mostly in their correct places. All your baby’s vital organs and body parts will be in place this week.
Baby size: A plum
Baby length: About 2.13 inches (54 mm)
Baby weight: About 0.49 oz (14 grams)
Read all about being 12 weeks pregnant here.
13 Weeks Pregnant
It is comparable to a lemon in length but looks almost like a miniature version of a newborn baby. A 13-week fetus looks very human.
Baby size: A lemon
Baby length: About 2.19 inches (74 mm)
Baby weight: About 0.81 oz (23 grams)
Read all about being 13 weeks pregnant here.
14 Weeks Pregnant
Your baby’s heart beats at a rate that is twice as fast as your own as it pumps blood to the organs and tissues within. Lanugo begins to grow over your baby’s entire body, which is a fine, downy covering of hair to help protect the skin while in the uterus for the remainder of the pregnancy.
Baby size: A peach
Baby length: About 3.42 inches (87 mm)
Baby weight: About 1.52 oz (43 grams)
Read all about being 14 weeks pregnant here.
15 Weeks Pregnant
At 15 weeks pregnant, your baby is now the length of an apple. Your baby is looking more “baby-like” day by day. It has developed so much that the baby’s gender can sometimes be revealed in an ultrasound this week—sometimes even earlier!
Baby size: An apple
Baby length: About 3.98 inches (101 mm)
Baby weight: About 2.47 oz (70 grams)
Read all about being 15 weeks pregnant here.
16 Weeks Pregnant
Your baby can now make faces, although not intentionally yet. But the facial muscles are working overtime, and it is possible to distinguish the baby’s expressions now, such as frowning, squinting, or even smiling.
Baby size: An avocado
Baby length: About 4.57 inches (116 mm)
Baby weight: Less than 3.53 oz (100 grams)
Read all about being 16 weeks pregnant here.
17 Weeks Pregnant
Your baby is now the size of a large onion or pear. The sweat glands have begun developing, and your child can hear now.
Baby size: A pear
Baby length: About 5.12 inches (130 mm)
Baby weight: About 4.94 oz (140 grams)
Read all about being 17 weeks pregnant here.
18 Weeks Pregnant
The facial features are moving into place. Although the ears may still stick away from the head, they are now in the correct position. Your baby’s eyes are looking straight ahead.
Baby size: A sweet potato
Baby length: About 5.59 inches (142 mm)
Baby weight: About 6.7 oz (190 grams)
Read all about being 18 weeks pregnant here.
19 Weeks Pregnant
When you are 19 weeks pregnant, your baby has developed a sweet tooth. If a sugar solution is injected into the womb, the baby will swallow twice as much of the amniotic fluid.
Baby size: A mango
Baby length: About 6.02 inches (153 mm)
Baby weight: About 8.47 oz (240 grams)
Read all about being 19 weeks pregnant here.
20 Weeks Pregnant
This week, your baby is swallowing more and “breathing in” the amniotic fluid. This helps prepare your little one for life outside the womb and supports the digestive system’s functioning. The ears are fully functional, and your baby can hear all uterine sounds, from your heart beating to louder sounds outside the womb.
Baby size: A banana
Baby length: About 6.46 inches (164 mm)
Baby weight: About 10.58 oz (300 grams)
Read all about being 20 weeks pregnant here.
21 Weeks Pregnant
When you are 21 weeks pregnant, an ultrasound can show your baby swallowing amniotic fluid. Your little one’s eyebrows and hair are growing and becoming thicker.
Baby size: A carrot
Baby length: About 10.51 inches (267 mm)
Baby weight: About 12.7 oz (360 grams)
Read all about being 21 weeks pregnant here.
22 Weeks Pregnant
Your baby is gaining weight rapidly, but the skin is still quite wrinkled. It is protected by fine hair called lanugo to help protect the baby within the uterus.
Baby size: A papaya
Baby length: About 10.94 inches (278 mm)
Baby weight: About 15.17 oz (430 grams)
Read all about being 22 weeks pregnant here.
23 Weeks Pregnant
Many fascinating things are happening within the womb as your baby clutches the umbilical cord, sucks its own thumb, and grabs other parts of the body as it carries about movement inside.
Baby size: An eggplant
Baby length: About 11.38 inches (289 mm)
Baby weight: About 1.10 lb (501 grams)
Read all about being 23 weeks pregnant here.
24 Weeks Pregnant
At 24 weeks, your baby’s body is proportionate, although everything is still tiny. The face is almost entirely formed, together with the eyelashes, eyebrows, and hair.
Baby size: An ear of corn
Baby length: About 11.81 inches (30 cm)
Baby weight: About 1.32 lb (600 grams)
Read all about being 24 weeks pregnant here.
25 Weeks Pregnant
When you are 25 weeks pregnant, your baby drinks amniotic fluid, which is actually quite healthy and contains carbohydrates, salt, proteins, and lipids, for example.
Baby size: An acorn squash
Baby length: About 13.62 inches (34.6 cm)
Baby weight: About 1.46 lb (660 grams)
Read all about being 25 weeks pregnant here.
26 Weeks Pregnant
At this point, your baby’s eyebrows and eyelashes are visible, and the hair continues to grow. You are now at a week when your baby’s eyes are opening, and I bet you are already thinking about their eye color.
Baby size: A zucchini
Baby length: About 14.02 inches (35.6 cm)
Baby weight: About 1.68 lb (760 grams)
Read all about being 26 weeks pregnant here.
27 Weeks Pregnant
Your child now opens and closes her eyes and sleeps and wakes up at regular intervals.
She may also be sucking her fingers during this time.
Baby size: A cauliflower
Baby length: About 14.41 inches (36.6 cm)
Baby weight: About 1.93 lb (875 grams)
Read all about being 27 weeks pregnant here.
28 Weeks Pregnant
Your baby’s brain now has billions of active neurons. It is possible to see clearly that a baby can dream during sleep. Brainwave activities can be measured and may now show the different sleep cycles like the rapid eye movement phase – a stage indicating that a dream is taking place.
Baby size: A kabocha melon
Baby length: About 14.80 inches (37.6 cm)
Baby weight: About 2.22 lb (1005 grams)
Read all about being 28 weeks pregnant here.
29 Weeks Pregnant
At this point, your little sweetie is perfectly formed. Your baby is a smaller version of what it will look like after birth. The baby’s fats continue to deposit under the skin, smoothing the previously wrinkled skin. These white fats serve as an energy source for the baby, explaining why it is so energized during this period.
Baby size: A butternut squash
Baby length: About 15.2 inches (38.6 cm)
Baby weight: About 2.54 lb (1153 grams)
Read all about being 29 weeks pregnant here.
30 Weeks Pregnant
By 30 weeks, all of the major body systems are formed and are now in the maturing phase. The significant development during this week is happening for your baby’s brain. Early in the pregnancy, the brain was just a smooth surface. Now, it is characterized by grooves and indentations.
Baby size: Cabbage
Baby length: About 15.71 inches (39.9 cm)
Baby weight: About 2.91 lb (1319 grams)
Read all about being 30 weeks pregnant here.
31 Weeks Pregnant
Your baby can now turn its head from side to side. You may also notice that your baby is moving a lot, which may cause you to sleep less. Take this positively. It only means having an active and healthy baby inside your womb.
Baby size: Leek
Baby length: About 16.18 inches (41.1 cm)
Baby weight: About 3.31 lb (1502 grams)
Read all about being 31 weeks pregnant here.
32 Weeks Pregnant
Toenails, fingernails, and hairs are already evident and even quite long for some babies. Your baby is still in a curled-up or shrimp position inside your womb, usually with head down and bottoms up, getting ready to be born.
Baby size: A napa cabbage
Baby length: About 16.19 inches (42.4 cm)
Baby weight: About 3.75 lb (1702 grams)
Read all about being 32 weeks pregnant here.
33 Weeks Pregnant
If you could peek into your uterus, you would see your newest family member functioning more or less like a newborn baby. They are sucking their thumb, have bouts of waking and sleeping, can distinguish between night and day, and can hear everything going on around them.
Baby size: A pineapple
Baby length: About 17.20 inches (43.7 cm)
Baby weight: About 4.23 lb (1918 grams)
Read all about being 33 weeks pregnant here.
34 Weeks Pregnant
Your baby’s lungs are still maturing, and they will continue to practice breathing by taking in amniotic fluid. This can cause your baby to have periodic bouts of hiccups, which can be felt by you or your partner most of the time.
Baby size: A cantaloupe
Baby length: About 17.72 inches (45 cm)
Baby weight: About 4.73 lb (2146 grams)
Read all about being 34 weeks pregnant here.
35 Weeks Pregnant
35 weeks pregnant, your baby is now ready to breathe. Being born this week probably still means spending some time in the incubator, but most often only for warmth and possibly food.
Baby size: Honeydew melon
Baby length: About 18.19 inches (46.2 cm)
Baby weight: About 5.25 lb (2383 grams)
Read all about being 35 weeks pregnant here.
36 Weeks Pregnant
Although most babies born at 36 weeks are perfectly healthy, they may still need monitoring for some time out of precaution.
The sucking reflex is now developed, and the further you go into week 36, the less likely it is that your baby will have problems nursing if born.
Baby size: Romaine
Baby length: About 18.66 inches (47.4 cm)
Baby weight: About 5.78 lb (2622 grams)
Read all about being 36 weeks pregnant here.
37 Weeks Pregnant
Each day, your baby gains fat stores that can measure almost half an ounce a day, which gives them a plumper appearance at birth instead of the pink, wrinkly skin they had before.
Baby size: Swiss chard
Baby length: About 19.13 inches (48.6 cm)
Baby weight: About 6.30lb (2859 grams)
Read all about being 37 weeks pregnant here.
38 Weeks Pregnant
The lanugo hair that has covered your baby’s skin during his or her time in the womb for protection is almost gone now but could still be apparent during delivery on the upper back and shoulders. Many infants will have a firm grasping reflex by now.
Baby size: Rhubarb
Baby length: About 19.61 inches (49.8 cm)
Baby weight: About 6.80 lb (3083 grams)
Read all about being 38 weeks pregnant here.
39 Weeks Pregnant
Your baby now looks like a newborn. Many of them have a lot of hair on their head and even long fingernails!
Baby size: A pumpkin
Baby length: About 19.96 inches (50.7 cm)
Baby weight: About 7.25 lb (3288 grams)
Read all about being 39 weeks pregnant here.
40 Weeks Pregnant
Your baby now looks like a newborn you will meet in person soon.
After you give birth, you’ll notice your baby’s body is covered in leftover blood, amniotic fluid, as well as lanugo (the thin, soft hair), and vernix (the waxy, white substance). The amount of it that will be found on the body differs from baby to baby.
Baby size: A watermelon
Baby length: About 20.16 inches (51.2 cm)
Baby weight: About 7.63 lb (3462 grams)
Read all about being 40 weeks pregnant here.
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References
Paula Dennholt founded Easy Baby Life in 2006 and has been a passionate parenting and pregnancy writer since then. Her parenting approach and writing are based on studies in cognitive-behavioral models and therapy for children and her experience as a mother and stepmother. Life as a parent has convinced her of how crucial it is to put relationships before rules. She strongly believes in positive parenting and a science-based approach.
Paula cooperates with a team of pediatricians who assist in reviewing and writing articles.