First Trimester: Weekly Summaries

Weeks 1 to 3 of Pregnancy This early stage covers your last menstrual period, ovulation, and conception. While you might not feel pregnant just yet, rapid cellular division is occurring as the fertilized egg journeys down the fallopian tube to implant securely in your uterus.

4 Weeks Pregnant Your baby is the size of a poppy seed. Implantation is now complete, and the pregnancy hormone (hCG) is rising rapidly, meaning this is the week a home pregnancy test will likely show a positive result.

5 Weeks Pregnant Your baby is the size of an apple seed. The neural tube, which eventually forms your baby’s brain and spinal cord, is beginning to develop. You may start experiencing early pregnancy signs like extreme fatigue and sore breasts.

6 Weeks Pregnant Your baby is the size of a sweet pea. A major milestone occurs this week: the heartbeat can often be detected on an early vaginal ultrasound. You might also notice that morning sickness is starting to set in.

7 Weeks Pregnant Your baby is the size of a blueberry. Tiny arm and leg buds are forming, and your baby’s brain is generating new cells at a rapid pace. Thanks to shifting hormones, you might experience frequent urination and sudden mood swings.

8 Weeks Pregnant Your baby is the size of a raspberry. Webbed fingers and toes are beginning to emerge, and internal organs are developing quickly. Continuing your prenatal vitamins is critical during this rapid developmental phase.

9 Weeks Pregnant Your baby is the size of a cherry. The embryonic tail has completely disappeared, and your baby is officially graduating from an embryo to a fetus. You might notice your clothes feeling tighter due to pregnancy bloating.

10 Weeks Pregnant Your baby is the size of a strawberry. Vital organs like the kidneys, brain, and liver are now functioning. Cartilage is also starting to harden into bone, and your baby’s joints are beginning to move.

11 Weeks Pregnant Your baby is the size of a fig. Your baby’s facial features are becoming much more defined, and tiny tooth buds are forming under the gums. You may notice your hair and nails growing faster than usual.

12 Weeks Pregnant Your baby is the size of a lime. Complex reflexes are developing, and your baby can now make a fist. For many mothers, reaching the end of the 12th week brings relief as the risk of miscarriage drops significantly.

13 Weeks Pregnant Your baby is the size of a peapod. Vocal cords are forming, and unique fingerprints are already in place on your baby’s tiny hands. Congratulations, you have successfully reached the end of the first trimester!

Second Trimester: Weekly Summaries

14 Weeks Pregnant Your baby is the size of a lemon. Welcome to the second trimester! Often called the “golden trimester,” you will likely experience a return of your energy, and the dreaded morning sickness usually begins to fade away.

15 Weeks Pregnant Your baby is the size of an apple. Your little one’s hearing is developing rapidly, and they can now hear the muffled sounds of your digestive system, your heartbeat, and even your voice.

16 Weeks Pregnant Your baby is the size of an avocado. Your baby’s eyes are becoming sensitive to light, even though their eyelids are still fused shut. Inside your womb, your baby is beginning to make facial expressions.

17 Weeks Pregnant Your baby is the size of a turnip. Your baby’s soft cartilage is gradually hardening into solid bone. Their umbilical cord, their lifeline to you, is growing thicker and stronger to carry more nutrients.

18 Weeks Pregnant Your baby is the size of a bell pepper. A protective coating called myelin is beginning to form around your baby’s nerves, which is essential for proper brain and nervous system functioning.

19 Weeks Pregnant Your baby is the size of an heirloom tomato. A greasy, white substance called vernix caseosa is forming over your baby’s delicate skin to protect it from the amniotic fluid.

20 Weeks Pregnant Your baby is the size of a banana. You have reached the halfway mark! You may now be feeling the “quickening”—those magical first flutters of your baby’s movement. You might also have your mid-pregnancy anatomy scan this week.

21 Weeks Pregnant Your baby is the size of a carrot. Your baby is consistently swallowing amniotic fluid, which is helping their digestive system practice for life outside the womb. You may feel more distinct kicks and jabs.

22 Weeks Pregnant Your baby is the size of a spaghetti squash. Your baby’s grip is getting stronger, and they are developing their sense of touch by exploring their own face and the umbilical cord.

23 Weeks Pregnant Your baby is the size of a large mango. Billions of brain cells are developing, and your baby can now hear loud noises from the outside world, like a dog barking or a vacuum cleaner.

24 Weeks Pregnant Your baby is the size of an ear of corn. Your baby’s skin is still thin and translucent, but their tiny lungs are beginning to produce surfactant, a substance that will help the air sacs stay open once they are born.

25 Weeks Pregnant Your baby is the size of a rutabaga. Baby fat is starting to accumulate, which will help smooth out their wrinkled skin and regulate their body temperature after birth.

26 Weeks Pregnant Your baby is the size of a scallion. Your baby’s eyes, which have been closed for months to allow the retinas to develop, are beginning to open. They are also starting to practice breathing movements.

27 Weeks Pregnant Your baby is the size of a cauliflower. Brain activity is surging, and your baby’s sleep-wake cycles are becoming more defined. Congratulations, you are at the very end of the second trimester!

Third Trimester: Weekly Summaries

28 Weeks Pregnant Your baby is the size of an eggplant. Welcome to the third and final trimester! A major milestone happens this week: your baby can now blink and open their eyes, and they can see light filtering through your womb.

29 Weeks Pregnant Your baby is the size of an acorn squash. Your baby’s bones are fully formed but still soft and pliable. You might be feeling stronger kicks and jabs as their muscles grow stronger and space gets tighter.

30 Weeks Pregnant Your baby is the size of a cabbage. Your baby’s brain is growing rapidly, developing the characteristic wrinkles and grooves that allow for more brain tissue. You might be experiencing shortness of breath as your uterus pushes against your diaphragm.

31 Weeks Pregnant Your baby is the size of a coconut. All five of your baby’s senses are now fully engaged. They can process information, track light, and perceive signals from all five senses.

32 Weeks Pregnant Your baby is the size of a jicama. Your baby is doing a lot of practice swallowing and breathing movements. At this stage, many babies start to shift into a head-down position in preparation for birth.

33 Weeks Pregnant Your baby is the size of a pineapple. Your baby’s immune system is developing rapidly as they receive essential antibodies from you. You might notice your Braxton Hicks (practice contractions) becoming more frequent.

34 Weeks Pregnant Your baby is the size of a cantaloupe. The central nervous system is maturing, and your baby’s lungs are almost fully developed. If born now, your baby would have an excellent chance of thriving outside the womb.

35 Weeks Pregnant Your baby is the size of a honeydew melon. Your baby is gaining weight rapidly—about half a pound a week! This essential baby fat will help them regulate their body temperature after birth.

36 Weeks Pregnant Your baby is the size of a papaya. Your baby may drop lower into your pelvis this week (a process called engagement or “lightening”). This will give your lungs more breathing room but will increase pressure on your bladder.

37 Weeks Pregnant Your baby is the size of romaine lettuce. Congratulations, your pregnancy is now considered “early term”! Your baby’s brain and lungs are fully ready to function in the outside world.

38 Weeks Pregnant Your baby is the size of a winter melon. Your baby is shedding the fine hair (lanugo) and the waxy white coating (vernix) that protected their skin in the womb. You are likely on high alert for early signs of labor.

39 Weeks Pregnant Your baby is the size of a mini watermelon. Your baby is considered full-term and is officially ready to be born. Your cervix may be softening, thinning, and dilating in preparation for delivery.

40 Weeks Pregnant Your baby is the size of a small pumpkin. You have reached your official due date! Don’t worry if your baby hasn’t arrived yet; it’s completely normal for first-time mothers to go slightly past their due dates.

Frequently Asked Questions (FAQs)

What are the most important prenatal vitamins in the first trimester? Folic acid is the most critical vitamin during the first trimester as it helps prevent major birth defects of the baby’s brain and spine (neural tube defects). Iron, calcium, and Vitamin D are also highly recommended to support rapid cellular growth.

When will I feel my baby move for the first time? Most first-time mothers feel their baby move between weeks 16 and 20 of pregnancy. This initial movement, often described as flutters or butterflies, is known clinically as “quickening.”

What should I pack in my hospital bag for the third trimester? You should pack your hospital bag by week 36. Essential items include your birth plan, comfortable maternity clothes, nursing bras, heavy-duty maternity pads, toiletries, an approved infant car seat, and coming-home outfits for both you and your baby.