It can be a full third of a pregnancy that a fetus - too big to move around much - is upside down in the womb. Gravity is at work there too, and the baby’s own heart is responsible for circulation. How do they avoid the problems an adult would have in the same situation?
They are completely surrounded by amniotic fluid which has about the same density they do. Even their airway and sinuses are filled with this fluid. Due to gravity, the fluid has the same vertical pressure gradient as the blood in the fetus’ circulatory system. As a result, the fetus doesn’t feel any of the adverse effects that an adult would notice when hanging upside down in the air by gravity boots.
Also they are smaller, so it’s not such a great pressure difference between head and toe, not to mention their curled up position, so blood doesn’t pool in the lower areas.
Another possibility is that they are basically in a sensory deprivation medium, no light, no temperature differential, muffled sound and no familiarity with up/down.
Actually, fetuses respond to both light and sound well before birth. Shining a flashlight at an pregnant woman’s stomach will get a reaction from the fetus about 12 weeks before birth (not that I’d recommend doing that).
Working in certain loud environments is enough to damage hearing as well, and they can hear the noises around them (talking, etc) too.
Too late! I’m off to find some fresh batteries and an occupied womb!
I don’t doubt they respond, just it’s not the same world as we live in.
I have heard about sound, and some takes on ultrasound as a fetus would hear it, but sound is still muffled and how often does someone hold a flashlight to a pregnant woman’s stomach?
Not often, but that was only to say they respond to changes in light, not that that’s the only type of light they respond to.
Point being, it’s not a sensory deprived environment, which is what you said that I was responding to.
How is it not? I’m not saying sensory input is totally absent, but it’s not what people outside the womb experience. It is similar to, in many ways sensory deprivation tanks where people are placed in a salt water warm fluid to float in with no light and muffled sound as a form of meditative relaxation.
I saw a pregger at my gym standing on her head. Freaked me out. It didn’t seem to bother her. I can imagine the baby saying WTF! It must be a shock for it.
During early zygote/fetus development, the head is bigger than the rest of the body. Even in a neonate, the head is much larger in proportion to the body than in an adult. It could be that their just isn’t enough, proportionally, blood and fluids in the body to cause uncomfortable pressure on the head when inverted.
Some time ago an expectant couple showed me an interesting trick: the sound of crumpling paper (didn’t have to be especially loud) would make the baby kick like crazy. This was about three weeks before the due date.
Sounds like they’ll be fun parents. Did they also show you the trick where a small kitten can jump 4 or 5 feet in the air if you chase it with a running vaccuum cleaner hose?
When swimming/diving, being upside down presents no problem to me with regards to blood flow/pooling. The only problem I have with being upside down is with water flowing into my nose, but a baby already has their nose/sinus cavities filled with fluid, so this wouldn’t be a problem for them.
In dive gear, with my mask in place, water entering the nose is no problem, and I’ve certainly been in a head down position with my feet directly above my head with no ill effect.
Why not? I can’t imagine it would hurt the fetus. If it’s in response to light, the woman probably deals with something similar several times a day.
One of my cats used to be able to jump up 5.5 feet when chasing a laser pointer. We never tried pursuing her with a vacuum cleaner hose to see if she could get any additional height.
Babies don’t mind being “upside down” in the womb because bankers haven’t yet figured out how to foreclose in the womb.
Rent The Tin Drum. In one of the early scenes you get some idea of how being upside down affects the fetus during birthing.
Not because it would really hurt it, mostly b/c fetuses at that stage sleep a hell of a lot, pretty much like a newborn who didn’t have to wake up to eat or poop would - it’d be about as nice as waking up a sleeping baby just for the hell of it.
The womb is not in anyway sensory deprivation, not in comparison to a sensory deprivation tank. The tank is intended to completely isolate a person from audio and visual cues. No sound. No light. Period. It’s large enough that a person does not bump into the shell of the tank while floating, and as they’re floating in warm salt water, there’s no extra sensation of touch.
The womb is filled with sounds - the mother’s heartbeat and breathing, digestive sounds, and the sounds of the world on the outside. Distorted and muffled, certainly, but far more audible than anything a person in a sensory deprivation tank could possibly encounter.
The baby is encased with several layers of membrane and the uterus. By the third trimester, it’s in the classic “fetal position”, because there isn’t enough room for it to stretch out. It’s encountering touch in every direction. If you watch a pregnant woman’s stomach while the baby is active, you will see her skin ripple as the baby pushes against it with a foot or a hand. You can even push back and get a reaction.
Second this. I’ve spent dives completely upside down (either walking under ice or in drift dives - it’s surreal), no blood pooling or balance problems at all.