Find out what’s going on during every stage of your pregnancy
Whether you just found out you’re expecting, halfway through, or near the end of your pregnancy, it’s important to know how your baby is developing and what’s taking place inside your body. Here’s a week-by-week guide:
Weeks 1-3
Your pregnancy doesn’t officially start until the first day of your last menstrual cycle, which is how your midwife or doctor figures out the due date. Technically you could be considered pregnant even before your uterus begins its important work. By the third week, things will be progressing and an embryo will have implanted itself in your womb.
It’s quite possible that you won’t have any symptoms during these first few weeks and you may not even have an inkling that you’re pregnant until your period is late.
Weeks 4-8
During the fourth and fifth weeks, the embryo starts growing quickly. Layers are being formed that will develop into different parts of the baby’s body, including the digestive, cardiovascular, and nervous systems. By the fifth week, the embryo is about the size of a sesame seed.
By week six, your baby will resemble a tadpole with little buds that will eventually become arms and legs. The beginnings of eyes and ears will also be visible. By seven weeks, the little head will start to dwarf the rest of the body due to the fast growth of the brain. Your baby will officially be a fetus by week eight and will be about the size of a grape.
As for you in these weeks, it’s possible you’ll feel some breast tenderness and you may be more sensitive to smells and tastes. You may also start experiencing occasional mood swings and symptoms of morning sickness (which can happen throughout the day, not just in the morning).
Weeks 9-12
Things are starting to get exciting now. In the ninth week, your baby’s face is forming and the eyes even have some color in them. There’s a noticeable mouth and tongue, and the hands, feet, and organs, including the heart, lungs, and brain, continue to develop. By week 10, tiny little ears are forming, along with the upper lip and nostrils. And, amazingly, the heart is now complete and beating at about 180 beats per minute.
All facial bones are formed by week 11, and by week 12, all muscles, organs, and bones are well developed, as are the sex organs. Your baby is now the size of a lime.
By this stage, your baby bump is starting to become more prominent and your breasts have probably gotten bigger. You may also find yourself having to pee often, and it’s possible that your vision may be slightly blurred. The good news? You’ll have that nice pregnancy glow.
Weeks 13-16
Week 13 is when the internal sex organs become completely developed and the outer genitals start to form, though don’t too excited yet; you won’t be able to find out whether it’s a boy or girl for a few more weeks. Around week 14, your baby will begin to swallow amniotic fluid, essentially testing out the kidneys.
By week 15, it’s time (if you haven’t already) to start talking or singing to your baby, as she will start hearing outside noises and the sound of your heart beating. And, incredibly, your baby will become sensitive to light. Her eyes will remain closed, but it’s possible she’ll notice a bright light shining on your belly. Your baby’s facial muscles can move in week 16 and you may even spot some expressions. If you’re lucky, you might catch your baby with her hands clasped in an ultrasound. She’s now about the size of an avocado.
If you’ve been dealing with morning sickness, it should be more manageable by now. You might also start to notice your skin getting darker in some places, especially your nipples and belly button. This is usually temporary. And if you feel flutters in your belly, it may not be nerves, it could be your baby kicking!
Weeks 17-20
Your baby is really growing now, and the head and body will be more in proportion. If you thought your baby looked like an alien before, now the face will look much more human. Although the eyes still won’t be open, they can move, and her mouth can open and close. Remarkably, your baby now has her own distinct fingerprints.
By now the baby is moving around a lot and you may even be able to get her to respond to loud noises. By 20 weeks, your baby is covered in vernix, which is a white substance that provides protection for the skin. This vernix gradually begins to wash away as the baby gets closer to full term, and when she is born, you may only see a bit in the cracks of her fingers and toes, if any at all. At 20 weeks she is about the size of a small banana.
Congrats to you, as you’ve made it to the halfway point! Your belly will be popping now, which may result in random people wanting to touch it. If you feel a little shaky on your feet, it’s because your center of gravity has changed, but you’ll adapt soon enough. You’ll also probably be feeling some discomfort in your belly, back or groin area, which is the result of your ever-growing uterus and baby putting pressure on the ligaments that hold your uterus in place.
Weeks 21-24
It’s during this time that your baby will start to be covered in lanugo, which is a soft hair that typically goes away before birth. Now your baby is developing a sleeping and waking pattern, though probably not the same as yours, as you’ll discover when it feels like he’s practicing karate at 2 a.m. While his lungs still have a way to go to be fully developed, he will start practicing his breathing to get ready for the big day. His size now is comparable to an ear of corn.
If you get stretch marks (not everybody does), you’ll probably see them forming during these weeks. Chances are you’ll also be hungry a lot of the time (possibly for some weird stuff) and you may have trouble sleeping.
Weeks 25-28
Your baby will almost certainly be moving around quite a lot by now, and you may even be able to feel her hiccups. Her eyes will open and her lungs, brain, and digestive system are developed, though not complete yet. You might want to pick up a stethoscope because you may be able to hear her heartbeat through your belly. Now’s she’s the size of an eggplant.
You’re headed to the home stretch; so, don’t let any heartburn you may experience get you down. If you notice that your hands, feet, or face seem bigger, this is probably due to water retention and it’s perfectly normal (but exercise, drinking enough water, and resting – especially putting your feet up – throughout the day, can minimize this).
Weeks 29-32
That wrinkled baby you’ve seen on ultrasounds will now be plumping up. The sucking reflex is starting and she may even suck his thumb. His r eyes can now focus. In anticipation of birth, his head should be pointed down, but don’t be alarmed if that hasn’t happened yet. Your baby is the size of a cabbage now.
Though it will all be worth it in the end (we promise!), by now with the extra weight you’re carrying around, it may be a chore just getting up to use the bathroom. Sleeplessness may increase too, as it can be difficult finding a comfortable position. Leg cramps are also common around this time.
Weeks 33-36
By week 33, your baby’s brain and nervous system are developed fully. And, apart from the skull, which must remain soft to get through the birth canal, all other bones are hardening. There’s not much room in your uterus now, and – just like you trying to sleep – your baby will move around to find better positions. You’ll be able to feel – and probably see – these movements. The lungs are completely formed and the digestive system is ready for breast milk. Baby size now: a head of romaine lettuce.
Starting at about 24 weeks, you may feel your womb tightening periodically. This is nothing to be alarmed about and it doesn’t mean you’re going into labor. These are Braxton Hicks contractions, which are sort of like a dress rehearsal for the big show.
Weeks 37-40
It’s almost time! If your baby’s head wasn’t pointed downward up until this point, now it should be. A pregnancy that’s reached 37 weeks is considered full-term, so basically now you play the waiting game.
If you’re expecting to give birth on your due date, that’s probably not going to happen, as only a small percentage of estimates turn out to be exact. While any sort of ache will probably make you think you need to grab your bag and head to the hospital, most likely labor will actually begin with mild cramps. But when it’s time, you’ll have patterned contractions that don’t go away, but keep getting longer, stronger, and closer together – so you’ll know you’re in labor! And before long (hopefully), you’ll have your baby in your arms and you’ll marvel at how in just about 40 weeks, she went from not even existing to the most beautiful thing in the world.
If you have any questions about this week in your pregnancy, or any part of your pregnancy and upcoming labor and birth, please don’t hesitate to get in touch so I can help you through!
