As you approach the end of pregnancy you might be wondering how your baby will breathe during labor or birth. Especially as he passes through the narrow birth canal.
This article will explain it all and help set your mind at rest.
Don’t worry. Your body, and your baby’s body, are perfectly designed for the birthing process.
When do babies start breathing in the womb?
From as early as 5-6 weeks of pregnancy, your baby’s umbilical cord begins to develop.
The umbilical cord is the lifeline between your baby and the placenta. The placenta is attached to the wall of the uterus and is where the exchange of nutrients and oxygen takes place between mother and baby.
In the uterus, your baby doesn’t breathe in the way you might expect. 100% of his oxygen comes from you, via the placenta.
How do babies breathe in amniotic fluid?
A baby’s lungs aren’t fully developed until around 34-36 weeks.
From around 12 weeks, though, your baby begins to practice ‘breath-like’ movements. At this stage, these practice breaths are more like swallowing movements.
Fetuses inhale tiny amounts of the amniotic fluids that surround them. These swallowing movements can be seen on ultrasound scan.
These breaths don’t bring oxygen into the lungs but expand and compress the air sacs (alveoli). This helps the lungs to mature and make the transition to life in the outside world once the baby is born.
How do babies breathe in the womb without drowning?
As we know, a fetus doesn’t use its lungs for breathing during pregnancy. However, there’s still plenty going on as the organs grow and develop.
Lung development starts at around 6 weeks, when tiny lung buds begin to form.
By 21 weeks, the respiratory cells begin to make a substance called surfactant, which coats the alveoli.
This stops the air sacs from collapsing in on themselves when the baby’s lungs aren’t inflated. Surfactant peaks between 26-28 weeks, and helps infants who are born prematurely.
By 26 weeks, tiny respiratory sacs begin to grow and multiply, and become known as alveoli by 34 weeks. The respiratory system is considered developed at 36 weeks.
At 40 weeks your baby will have around 150 million alveoli. By the time your child is 8, he’ll have another 150 million, the same number as adults.
During pregnancy, the alveoli are filled with fluids. This is a normal part of their development. Because the alveoli are designed to be filled with fluids, this prevents your baby from drowning during pregnancy and in the labor process.
Aren’t our bodies incredible?
When do babies take their first breath?
When a baby is born, he undergoes a complex and intricate transition. In the initial moments after birth, your baby’s blood flow switches from what’s known as fetal circulation, to newborn circulation.
The change equips your baby with all that’s needed to be able to take that all-important first big breath.
Most infants make this transition seamlessly, but some need a little extra encouragement.
In pregnancy, blood bypasses a baby’s lungs by flowing in different pathways, through openings known as shunts.
At birth, babies inhale sharply and breathe for the first time on their own. This breath is mainly triggered by the change in air temperature and the lack of amniotic fluid.
The pressure reduces and closes special valves in the baby’s heart. This, in turn, redirects blood flow to the lungs for the first time. As your baby inhales, oxygen is collected from the lungs and transported through the blood vessels to all the baby’s body tissues and organs.
Even when your baby breathes for himself in the first moments after birth, he is also still receiving oxygen via the placenta and umbilical cord. This gives him a dual oxygen supply.
Blood will gradually stop flowing to the placenta and umbilical cord after birth. The timing of this varies for each baby but can range from 5-30 minutes if the cord is left unclamped.
Can babies breathe underwater during birth?
When a baby is born into water, he behaves as if still in the uterus.
Fetuses are used to a watery environment, as they spend all those months floating in the amniotic fluids surrounding them. So being born into water is no big deal for them.
A water birth mimics the environment of the womb.
As a baby emerges into a birthing pool, for example, his lungs aren’t open. The alveoli are already filled with fluid, so no more water can enter.
Your baby won’t actually breathe until he’s brought out of the water.
You might be surprised to learn that being born isn’t what triggers the breathing reflex.
The first breath is triggered by environmental stimuli, such as a change in temperature, lack of fluids, exposure to air, or stimulation by touch.
This is why a baby won’t be triggered to breathe (if left untouched) until he’s brought out of the water.
If you’re planning a water birth experience, your midwife will check the pool temperature frequently. The water should be kept around body temperature (36.5-37 degrees). This minimizes the change in environment when your baby’s born.
Does a baby breathe before the umbilical cord is cut?
Babies are often already breathing independently for themselves before the umbilical cord is cut.
The umbilical cord delivers oxygen to the baby until blood flow to the placenta stops after birth. The timings will vary for each mother and baby pair.
Until then, the blood and oxygen will keep flowing to your little one, even once you have him in your arms, as long as the cord is not clamped. The cord clamps itself naturally, and then turns white, signaling the blood transfer is complete.
Delayed cord clamping will ensure your baby receives as much blood, oxygen, and precious stem cells from the cord as possible.
Do babies feel pain during birth?
We know newborn babies can feel pain while in the uterus. So it seems safe to assume during labor and birth they’ll experience some level of discomfort or sensation.
They are squeezed with tightenings and contractions, they have to navigate their head through the pelvis, and their head is molded as they enter the birth canal.
Certain medications in labor will affect your baby’s activity levels. For example, opiate-based medication will make a baby feel drowsy in the same way it does for the mother.
It’s important to remember, the squeezing a baby experiences from contractions, or from passing through the birth canal, serves a really important purpose. It helps to push out the fluid from the lungs to prepare them for that first huge breath.
Studies suggest infants born by c-section are more likely to experience respiratory problems at birth as they haven’t received that same big squeeze to help them clear the fluids. This also means they’re less able to take in as much oxygen because there’s still fluid in the lungs.
Read Birth From Your Baby’s Point Of View for more information.
Can a baby breathe in the birth canal?
A baby is highly unlikely to breathe in the birth canal during a vaginal birth.
Infants are not designed to do that. As they’re being squeezed through the birth passage, their lungs are compressed, making it nearly impossible for them to inflate them.
The purpose of this squeeze is to push out as much fluid as possible from their air sacs, in readiness for their entrance into the world. Once they’re born, their chest recoils and allows them to intake more air and oxygen for effective breathing.
Occasionally babies will gasp in labor or birth. This is slightly different from regular breathing and normally will only occur if a baby’s oxygen levels are worryingly low, or restricted in some way.
Occasionally this can occur when meconium is present in the amniotic fluids. This gasping can lead to a condition known as Meconium Aspiration Syndrome, where babies inhale meconium into their lungs.
This affects their ability to inflate their lungs properly, makes breathing more difficult, and can lead to complications.
How do babies poop in the womb?
While they are still in the uterus, most babies don’t poop.
They aren’t ingesting food for themselves, as they receive their nutrients via the placenta, so their gut system doesn’t function yet.
But the fetus does ingest a few things.
Your baby swallows a build-up of old skin cells, hair, vernix, and enzymes, which are present in the amniotic fluids. This collection of waste forms a sticky substance, known as meconium, in the baby’s intestines.
Sometimes fetuses do pass meconium during birth. This can be a sign of fetal distress, where the sphincter muscles around the anus relax momentarily due to reduced oxygen levels.
It can also be a sign of post maturity. Passing meconium is much more common after 40 weeks.
How do I know if my baby is getting enough oxygen in the womb?
When a baby is active, it’s a strong indicator of overall health and wellbeing. Any deviation from that can be an early sign something is wrong.
During labor, your baby’s heart rate will be monitored closely, either with a pinard stethoscope, a handheld doppler, or by CTG (cardiotocography) machine. This is called fetal monitoring.
If a baby isn’t getting enough oxygen during birth, this can usually be detected in the heart rate patterns.
A deviation from the normal rate and pattern will alert your midwife or doctor that there could be a problem.
Find out more in Baby’s Heart Rate During Labour – What’s Normal And What’s Not.
You’ll also feel your baby kicking and moving during the birth process. If you notice a reduction in your baby’s movements, contact your maternity unit immediately for health information and advice.
Babies don’t go quiet before labor so it’s important to have a check-up.