You Won't Believe What Your Fetus Is Doing Right Now
There’s no doubt about it — every baby is a miracle. The entire journey, from conception to birth, consists of so many intricate, challenging processes. But most moms-to-be are preoccupied with all the common side effects of pregnancy (nausea, bloating, heartburn and tiredness) that they are not completely aware of all the mind-blowing things that are taking place inside them.
Your body provides a very comfortable place for your baby to hang out for 40 weeks before it’s time for them to make a grand entrance, but they’re not just chilling out in there. Even when sleeping, they are working hard to foster the skills, reflexes and strengths required to survive in the outside world. Your baby’s growing and developing on a daily basis and doing some really cool stuff that might come as a surprise.
Here are 13 amazing things your baby is doing right now.
Swimming in Urine
Before your baby is even a fetus (the embryo transforms into a fetus around week 11 of pregnancy), they start to pee inside their amniotic sac. However, it’s only later on, when kidney development is more complete around week 14, that they ramp up urine production.
For most of the time they’re in your womb, your baby is basically swimming in — and drinking — a mixture of amniotic fluid and their own pee. This sounds gross, but it’s completely sterile and harmless. By week 20, most of the amniotic fluid is urine. And in case you’re interested, around 13 percent of babies poop in the womb.
Your probably won’t see — or feel! — your tot’s teeth until they’re between four and seven months old, but their tiny tooth buds are already developing under their gums only 10 weeks into your pregnancy. (At this stage, they’re likely to be growing hair follicles and fingernails, too.)
Their permanent teeth start to form at around 20 weeks, and by the time they’re born, they have 20 baby teeth hidden within their gums, waiting to pop out and possibly cause them (and you) no end of discomfort and pain.
Favoring Sweet Tastes
Your tot’s taste buds start forming around week 11, right where their tongue will grow. Eventually, these will differentiate between five tastes: sweet, salty, bitter, sour and umami. By around week 16, taste pores (small surface pits on the surface) will have developed on their tiny tongue, which lets them experience their first taste: salty amniotic fluid. Throughout the rest of your pregnancy, molecules of the food you eat make their way into your baby’s amniotic fluid, via your blood and the placenta.
At around week 28, your baby’s taste buds are fully mature, giving them stronger flavors of everything you eat. Scientists believe that babies begin to show a preference for sweet flavors in the womb by swallowing more amniotic fluid when it is sweet, and less when it is bitter. Studies have also shown that mothers who eat a lot of certain foods have babies who enjoy those same foods after they are born, so if you want your kid to be a veggie lover, stock up on the green stuff.
Grimacing and Grinning
By the time your second trimester starts in week 14, your baby is giving their facial muscles a real workout. Their brain impulses make it possible for them to squint, frown, grimace and even smile. However, they don’t yet have the cognitive ability to feel the emotions we’d commonly associate with different expressions.
It won’t be long before their eyes are making small side-to-side movements and can perceive light, even though their eyelids are still sealed shut. By about 24 weeks, your baby is likely to be yawning regularly, although some scientists believe it’s not actually yawning but simply the opening and closing of the mouth. Another theory is that yawning for babies in the womb may be a sign of their maturing brain, and not sleepiness.
Sucking and Swallowing
After about 17 weeks in the womb, most of your baby’s survival skills are being perfected. They’re practicing their sucking and swallowing skills to prepare for what they’ll spend most of their early days doing: feeding!
The sucking reflex begins around the 32nd week of pregnancy, but by week, 20 their thumb may have found its way into their mouth. (This doesn’t mean they’ll continue to suck their thumb through childhood, though). The power of the sucking reflex is clear after birth, when your baby automatically starts sucking when your nipple or a bottle teat touches the roof of their mouth.
Your baby starts to develop pads on their fingers and palms during the second and third months of pregnancy. Around week 23, your baby is forming fingerprints on their teeny fingers and toes, made up of arching, looping and whirling patterns that are completely unique to them.
From this point, their fingerprints won’t change — they will simply expand as they grow throughout their life. (This means that, in theory, it’s possible for a fingerprint from 20 weeks after conception to be used to identify a 40-year-old.)
As well as the sucking reflex, your baby will be born with eight other reflexes, which are all unique to newborns. One of these is the Moro reflex, also known as the startle reflex, which is designed to help protect your baby from danger. Your baby starts to develop this reflex at about week 25 of your pregnancy. It occurs when they are sleeping and are suddenly startled awake with a quick, sudden movement. It could be caused by your sneezing, a dog barking, a door slamming or any other kind of loud, unexpected noise.
The Moro reflex peaks during the first month postpartum, but completely disappears after two months. Other reflexes developed in utero are the “rooting” reflex, which prompts your baby to turn their head toward your hand if you stroke their cheek or touch the corner of their mouth, and helps them find your breast or bottle at feeding time. There's also the grasp reflex, which occurs when you stroke the palm of your baby’s hand and watch them immediately grip your finger. This lasts until about about five to six months of age.
According to a 2005 study published in the “Archives of Disease in Childhood,” babies may cry in the womb. This was found on accident during a study of mothers who used cigarettes or cocaine during pregnancy (there was no suggestion that the “crying” was caused by exposure to tobacco or cocaine).
After researchers played a sound on the pregnant mothers' bellies, ultrasound videos showed the babies startled, opening their mouths, gasping and even quivering their chins. The researchers believe the results are proof of a fifth, previously unknown behavioral state for human fetuses, in addition to quiet sleep, active state, quiet awake and active awake.
Hic, Hic, Hiccuping
You may start to notice your baby’s hiccups in your second or third trimester. These are caused by fluid from the amniotic sac getting into, and then leaving, your baby’s lungs, which makes their diaphragm contract quickly.
When your baby hiccups, you’re likely to notice a series of tiny, rhythmic tapping sensations, which are much softer than the kicks you might also be receiving on an ever-increasing basis. While hiccups are good indicators that your baby’s central nervous system is developing normally, don’t worry if you haven’t felt any — they can happen without you noticing.
Recognizing Your Voice
You’ve probably been chatting to your baby throughout your pregnancy, and by about 27 weeks, you’ll finally have an avid listener — although you won’t get a vocal response for awhile yet! By this stage of your pregnancy, your baby’s auditory development may allow them to recognize your voice, even though it is muffled by amniotic fluid, all the layers of your body and the creamy coating of vernix that will remain all over their skin until after they are born.
This is a great time to play music and encourage other family members to talk to the baby through your bump, although they’ll still favor your voice, which might be because it’s the only voice communicated in two ways: both by ambient sounds through the abdomen and internally through vibration of your vocal chords. (On the other hand, external voices are only heard as ambient sounds.) In the third trimester, your baby can recognize your voice and responds to it with an increased heart rate that suggests they are more alert when you’re speaking.
By week 28, your baby can open their eyes, hear sounds and has moving arms and legs. So it’s only natural that they want to play — and the only “toy” within reach is the umbilical cord.
Ultrasounds have discovered that babies grab onto their umbilical cords, which may even result in them temporarily cutting off their own oxygen supply. (Don’t worry, this is perfectly normal — some babies even put the umbilical cord in their mouths.) Incidentally, babies who are more active, particularly in the second trimester, typically have longer cords.
Having Sweet Dreams
Your baby will experience REM (rapid eye movement) sleep at around week 28, which means they might even be dreaming. At 32 weeks, your baby sleeps 90 to 95 percent of the day. Scientists believe that, just like babies after birth, unborn babies probably dream about what’s familiar to them — the sensations they experience in the womb.
Scientists can only make assumptions about whether babies dream inside the womb (fetal brain waves cannot be monitored), but a team of German researchers studied how sheep fetuses (which are similar to human fetuses in some ways) enter a dream-like state weeks before REM movements are detected. By week 34, your baby is developing sleep habits they’ll continue for the rest of their life, by closing their eyes when they’re asleep and opening them when they’re awake.
After 37 weeks in the womb, your baby is gearing up for their much-anticipated entrance. They’re inhaling and exhaling amniotic fluid, blinking and turning their body from side to side. While their lungs are now fully mature, their brain will continue to grow until they’re in their 20s. However, their little brain is already capable of incredible things.
A research project indicated that babies who had songs played to them in the womb were able to recognize that same song many months after they were born. Researchers played "Twinkle, Twinkle, Little Star" very loudly several times a day during the last trimester of pregnancy. A few days after these babies were born, researchers took recordings by using electrodes on different sections of their brains. When the babies heard “Twinkle, Twinkle, Little Star” again, they exhibited a significantly greater brain response than the babies in a control group did. Next, researchers changed a few notes in the song while the babies' brains were being recorded. Incredibly, the babies’ brain activity appeared to indicate that they were aware of this change.