Your Week By Week Look At Baby's Progress In Pregnacy

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In this look at how your pregnancy will progress, you’ll see what happens each week of your pregnancy. Know what to expect for your growing baby and yourself.

Please note: I am not a doctor and the following information is not intended to provide or replace medical advice; it is for entertainment and informational purposes only.

pregnant woman with text "Your week by week pregnancy guide" from The Moments At Home

If this is your first baby then you may be wondering how your pregnancy will progress from week to week. Even if it’s not your first, it’s fun to keep track of your baby’s progression with weekly charts that guide you and give you information along the way.

You may be surprised how much can happen during pregnancy week by week; some of the changes are obvious and some you might miss if you weren’t aware. It’s a lot of fun to follow along with what’s happening inside of you so you can enjoy watching this miracle unfold.

Once you figure out your pregnancy due date, then you can start looking ahead at all the wonderful and unique milestones coming your way.

For a quicker glimpse, you can check out this pregnancy trimester guide. And you want to know what’s going on for you, this month-by-month pregnancy overview for mom will give the low down on what you’ll be feeling and experiencing.

The following are general guidelines on your baby’s growth in each official week of pregnancy. For an in-depth look at each trimester, check out your Ultimate Pregnancy Guide By Trimester.

First Trimester: Weeks 1-12 Pregnancy Guide

1 Week Pregnant – This is actually going to be the week of your last period, so you haven’t conceived your baby yet. But since it’s instrumental in determining your due date, it’s part of your 40 week pregnancy timeline.
2 Weeks Pregnant – Toward the end of week 2 is generally when conception occurs. Even though you’ll have no real clue something miraculous is happening inside of you, your baby’s gender and genetic characteristics are already determined.
3 Weeks Pregnant – During this week your baby goes from a single cell that is alive into multiple cells. It will travel through your reproductive system to find its home in your uterine wall and begin to grow in your womb.
4 Weeks Pregnant – Smaller than a grain of rice, your baby is nonetheless growing and taking awesome shape. By the end of this week, your little one’s digestive system will be formed and you may have an inkling he or she is there.
5 Weeks Pregnant – The beginning of your baby’s central nervous system is forming this week; you’re possibly just becoming aware of your little surprise.
6 Weeks Pregnant – This is when most women learn they are expecting because the baby begins to release hormones that will stop their mom from getting her menstrual cycle…and some queasiness (although some mamas even notice that in the 4th or 5th weeks).
7 Weeks Pregnant – Not only is there is a distance heart beating in your baby, but he or she also has an amniotic sac and placenta that is beginning to provide oxygen and nutrition. Every single vital organ your baby will be born with has started to develop.
8 Weeks Pregnant – Your baby may look a little more like a tadpole than a baby at this point, but that’s because it’s spinal cord is longer than its body right now and his or her head is disproportionately large as well. Your baby is nearly 1 1/2 cm long this week!
9 Weeks Pregnant – Your baby is able to move about, its liver is producing blood cells, and he or she has a mouth and tongue as well as eyes developing. Baby is starting to such his or her thumb.
10 Weeks Pregnant – Your baby is now growing faster than before and has fingers, peach fuzz all over and even though you don’t feel it, is kicking his legs. He is only a quarter of an ounce in weight and is just over an inch long. All of his or her organs are formed and brain waves are active.
11 Weeks Pregnant – Now the baby is nearly fully formed and bones are forming. He or she is an inch and half long.
12 Weeks Pregnant – The reflexes are starting to make an impact as your sweet baby starts opening and closing its hands and starts making stronger sucking motions.

Second Trimester: Weeks 13-26 Pregnancy Guide

13 Weeks Pregnant – During this week your baby’s fingers now have their own unique fingerprints, all of his or her organs have formed, and the head is larger than the body. They already weigh an ounce and is about three inches in length.
14 Weeks Pregnant – Your darling baby is now making facial movements by smiling and frowning and suckling its thumb. E en though you can’t see his or her face, it’s beginning to show expression.
15 Weeks Pregnant – Lungs are now forming as are taste buds, and your baby is about two and a half ounces in weight and is four inches long from the head to the rear.
16 Weeks Pregnant – At this stage the growing, progress becomes very fast and now everything is starting to move where they will be at birth (like baby’s eyes).
17 Weeks Pregnant – The spine is changing from cartilage to bone and sweat glands are now starting to form. Little one is now five inches long and weighs about five ounces.
18 Weeks Pregnant – This is the time your baby becomes noticeably more active and you may start to feel little flutters as it exercises tiny arms and legs start flexing.
19 Weeks Pregnant – Baby’s brain is now working overtime and the eyes, ears and all other sensory functions are now fully in place. They can hear you so this is when you should start reading and talking to your baby, as should daddy and any siblings.
20 Weeks Pregnant – At this point your baby is measured from head to foot rather than from head to the bottom and it is six and a half inches long and weighs close to eleven ounces.

pregnant belly with a clock in front; counting down week by week for pregnancy

21 Weeks Pregnant – Now your darling wee one has eyelashes and eyebrows and you should begin to really feel the flutters as they kick. For baby girls, the vagina has started to form.
22 Weeks Pregnant – Your baby is now eleven inches long and weighs a pound and is starting to look like a newborn baby and is covered by a light fur called lanugo.
23 Weeks Pregnant – Your baby can now feel you move and is used to hearing your voice and other noises that would have startled it previously. Bonding is already well on its way and when your baby is born, they will know your voice from hearing it even now.
24 Weeks Pregnant – When the baby is this old, it is nearly a foot long and weighs over a pound. Everything is becoming more pronounced in his or her features and weight is starting to fill them out.
25 Weeks Pregnant – Your baby’s skin is now starting to fill out and is no longer wrinkled and his or her lungs are continuing with their growth.
26 Weeks Pregnant – Ears are hearing better and low conversations can be heard and the hair on the baby’s head is now the color it will be at birth.

Third Trimester: Weeks 27-40 Pregnancy Guide

27 Weeks Pregnant – This is the point where your baby’s sleep cycle is more patterned and you’ll notice movement at certain times of the day or night. He or she is developing a rhythm you’ll be able to predict.
28 Weeks Pregnant – Your little one can blink now and is opening and closing his or her eyes and can see light better that filters into the womb.
29 Weeks Pregnant – He or she now weighs two and a half pounds and is fifteen inches long. You are now well into your third trimester and all aspects of your baby’s body are growing and bulking up.
30 Weeks Pregnant – Your baby continues to grow and their brain is dreaming (maybe of meeting you very soon!).
31 Weeks Pregnant – Your baby is getting bigger and developing their senses.
32 Weeks Pregnant – Your baby is sleeping a lot now and when he or she is awake, their movements are strong and coordinated such as thumb sucking, breathing, and practicing their soccer kicks. It’s pretty likely that their head is down as they prepare for birth.
33 Weeks Pregnant – Your baby’s immune system is being strengthened this week.
34 Weeks Pregnant – If you’re having a boy, this is the week his boy parts fall into place.
35 Weeks Pregnant – With a rapidly growing brain, your baby’s head is beginning to weigh a good bit more and you’re likely noticing pressure from that.
36 Weeks Pregnant – Your little one’s lungs are rapidly developing at this point, his or her head is nestled in your pelvis (waddling, mama?), and while birth at this point would be premature, chances for a healthy future are much stronger at this point.
37 Weeks Pregnant – Baby is suckling, somersaulting, and getting ready to be born.
38 Weeks Pregnant – Your baby is beginning to produce surfactant, which is necessary for those first breaths outside the womb.
39 Weeks Pregnant – Baby’s brain continues to develop as he or she maxes out their room in the womb and prepares to come out.
40 Weeks Pregnant – This is officially the week of your due date and baby will appear when baby is ready. Some women naturally go into labor before this point, and others after.

Keep in mind that all pregnancies are different the progress offered above is just a general guideline to the progress of pregnancy. If you have any concerns, you should always talk to your OB or midwife.

To read more in depth details about each week, check out this site that will explain in more depth. And of course, here’s a great overview for mom, baby, and what to do each trimester.