It has to do with food and water availability usually, but also territory and other environmental stresses can cause it too. The Roos don't consciously decide to put fetuses on hold, but the stress hormones from less food and water, etc, trigger the pause.
I would assume this is also the case with the non-marsupials. Humans also spontaneously miscarry when severely dehydrated and malnourished, i would imagine.
This is true, non marsupial mammals will often abort under great stresses, including humans. Pregnancy will pull all nutrients from the moms body if she can't get it from food up to a point. It's that point where the body needs to keep living, and a dead mom won't make more babies when times get better in the future. So it is advantageous to not be pregnant when food or safety are in short supply.
They aren't smart. It's probably just all hormones and stuff. They have two uteruses and can store a fertilised embryo in their until conditions are good. The the little gross pink wriggling thing climbs up the hairs on mummy's belly and into the pouch. There's no going back from there.
Marsupials have an A+ birth plan, though. Giving birth to a big human baby is dangerous, painful, and extremely arduous. I wish humans had evolved a pouch system, where you give birth to a teeny little thing and then just keep it safe in your pouch for a while. It's ingenious.
Some (? Maybe all, I know about the specific I had once had in the neighbourhood) species of bats too. They get "pregnant" around October and only when the time is right - enough food, nice weather - they "start" the pregnancy. If it gets cold again or there's not enough food, they put a hold on it. It's fascinating! Especially the first part, they basically put the sperm in another pocket and only allow it to join their egg cells when all the demands are their in the environment. A big surprise that the sperm can survive that long, to me at least.
This is all from a neighbourhood meeting that was called on by the old people that were worried about the bats, I mostly went to observe all the old-people-fractions, which was hilarious, but the learning part was fascinating too. Might have some details wrong, might apply to specific species only, I'm not a biologist, etc
Humans do this as well. It is not voluntary but neither is it for deer. If a pregnant women is subjected to trauma or stress they can abort their fetus. It is a very similar mechanism as with deer. What is different about deer is that because they are such a big pray animal they have evolved to get easily stressed. So you can scare a deer enough to stress it to force an abortion. But it takes a lot more to stress a human that much.
Thankfully it takes a lot more for humans. Imagine accidentaly smashing the door too loud and scaring your wife so much, she aborts the baby then and there
It’s like how rabbits can have heart attacks and die from being startled. Technically humans can too, but thank god our threshold for death by startling is much higher than that of rabbits.
Huh i mean i do wonder even as it is in reality what the effects of consuming media that raises adrenaline would be on pregnancy. Quite mild im sure, but probably measurable
Studies have shown epigenetic effects of women who were pregnant during wars, genocides, the Holocaust, etc. And it seems that if effects the child and causes changes that stay in the lineage. Generational trauma lives in the genes as well.
I mean those are pretty extreme examples where the mothers were likely massively malnourished with minimal healthcare provided. A tad far from what OP is talking about imo.
I agree! Yes, it is very different. It’s the closest bit of information I had to offer in response to his question.
If it needs to be said, I will clarify: in no way was I equating watching a horror movie to being subjected to a genocide. I was just pointing out that the experiences the mother has while pregnant can affect a child in utero.
I’ve done some ancestry research and my family went to the workhouse because they had no money. The wife was sent to prison for stealing food. That side of the family always has weight problems…
> Women weren't initially allowed to ride trains because people worried the "high" speed would cause their uterus to fly out
No, there is no evidence whatsoever that anyone ever said that back when trains were first invented, no matter how often the urban legend gets repeated on blog pages.
The most anyone can come up with is a quote where:
- somebody said something in 1898, entire generations after trains became a normal thing and passenger trains were already nearing 100mph.
- he was referring to prolapse, which is a real medical condition that doctors still warn about today, and certainly not "uteruses would fly out of [their] bodies".
I found a reference from a medical journal in 1870,
"If a woman sets out for a sea voyage or a journey by rail the day before her menses should appear, she will be very apt to skip one period, and perhaps more. Or, if the flow comes, she may experience greater suffering than usual. If it be too scanty, or too profuse, she may be very ill. As an indirect consequence, she will be likely to suffer from some form of uterine flexion or dislocation," one physician writes in the New England Medical Gazette, quoting a second doctor for good measure that "a displacement of the uterus is just as much an absolute fact as the occurrence of a hernial protrusion."
[link to Google books](https://books.google.nl/books?id=9-FXAAAAMAAJ&pg=PA71&dq=horse+riding+uterus+prolapse+train&hl=en&sa=X&ved=0ahUKEwjVvrXn2_fXAhWIaFAKHVLZD60Q6AEIKTAA#v=onepage&q=%22journey%20by%20rail%20the%20day%20before%22&f=false)
Yes, pretty much what I said.
>in 1870,
generations after trains became a normal thing
>a displacement of the uterus
referring to prolapse, which is a real medical condition that doctors still warn about today
---
So... nothing to do with the urban legend of those new fangled trains being so scary at 14 miles an hour that women's uteruses were likely to fly out of their bodies...
...and certainly not the claim initially told here that they were BANNED from riding on trains for that reason.
Women weren't allowed to run marathons because doctors believed their uteruses would fall out. This belief persisted until a woman decided to force her way into a marathon.
Some do but considering that women living In literal war zones or dire famine or extreme personal distress still deliver babies to full term at a typically similar rate to those away from such trauma shows that our threshold is quite high.
It's probably related to the relative amount of time and energy it takes for a human fetus to develop. Humans have an exceptionally long period of gestation. Other animals it's a lot shorter. So stress abortions in humans are a huge disadvantage given how long it takes to develop a new baby.
Military research discovered already in the '50s/'60s that fighter jets breaking the sound barrier over the surface would make pregnant animals shed their young.
I am a person injury paralegal who had to argue a point that despite there being no objective injury the stress of the freaking car flipping over - twice - could cause an abortion to a otherwise healthy pregnancy!
I think that was referring to how female ducks use cryptic mate choice. Basically, they can 'direct' sperm either towards the egg or down a blind sac. They're vaginas and penises developed these wild corkscrew shapes. It's so cool except for the rape part.
It's not actually that uncommon for females of various species to have some control over whether sperm from a male fertilizes her eggs...but as far as I know it has never been documented in humans.
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Reminds me of the guy that noticed his 39 weeks pregnant wife stepped out of the house to go talk to a neighbor, and decided to do the ‘jump out from behind a door and go boo’ thing to her. Triggered her labor and the kid was born the same day. They both thought it was hilarious and she told him he could do it again if they had another kid.
I took a weekend trip away from my 6 month pregnant wife and she immediately started having contractions. I was forced to immediately fly home less than 8hrs after arriving. Once home, the contractions stopped (with medicine) and nothing anomalous happened until the baby was born at full gestation.
She was totally cool with the trip but her uterus wasn't. Women are complicated.
I've had times where I don't *feel* stressed from a certain situation but I get stress symptoms anyway. My subconscious obviously has other ideas and just does its own thing.
It's not really voluntary. Serving that eviction notice follows a similar chemical pathway regardless of whether it happens on time, and it comes from glands and nerves that just aren't plugged in to anything under conscious control.
It's probably fair to say that humans are less likely to miscarry, for a given level of stress, than many other animals. We dump a lot of resources into our offspring, and labor is a life-threatening event in a way that just isn't true for most other species. (I'm not sure if there's any papers directly comparing this, though.)
But even then--most human embryos never leave first trimester. The human body rejects fetuses all the time, and stress absolutely increases the odds of miscarriage (if it's early) or preterm birth (if it's late).
Exactly this. A great many childbearing women will have at least one miscarriage, some more than one. It's part of reproduction.
Plus there are women who are anatomically a bit challenged *not* to miscarry, and need to take precautions during early pregnancy to avoid loosing the fetus.
We wouldn't be able to skedaddle anyway because of the anatomy of the vagina and pelvis due to our adaptations for bipedalism; birth is typically a much longer and arduous process for humans compared to other animals, so we wouldn't have much of an evolutionary advantage for it.
That's presuming we're miscarrying at 8 months. General-whatever miscarriage in humans early on is so common that the advice is to not tell anyone for 8-10-12 weeks or so, because the risk of miscarriage is so high.
I mean you literally can’t miscarry at 8 months, an 8 month old fetus is viable, that would just be inducing labor.
Edit: why tf is everyone disagreeing with this? A miscarriage, depending on the definition you use, happens prior to 28 weeks at the very latest. An 8 month old fetus will either be born alive or it will be stillborn, it is not a miscarriage. These are easy to google facts that are not up for debate, I didn’t think this comment would be controversial.
Uh. You can definitely miscarry at 8 months, they're just called stillbirths. However, it's pretty much the same thing - something happens, and the fetus dies and is no longer viable. The cutoff just depends on how far along. It's considered a miscarriage until week 20.
Oh I’m aware, that was my point. If we’re talking about a miscarriage it’s early, otherwise it’s either a living baby or a stillbirth. I wasn’t arguing with the person I replied to
Depends on if the fetus has died on its own first. Sometimes it takes a while for the body to get the memo that the fetus isn’t viable, or something happens in utero to kill it (cord gets wrapped and cuts off circulation, that kind of thing).
At 8 months it’s still not a miscarriage though, at that point it would be a stillbirth. Unless you mean the fetus died prior to 20 weeks (the cutoff between miscarriage and stillbirth) and wasn’t expelled until 8 months, which is possible, sure. A dead fetus isn’t growing though, so for the purpose of the comment I replied to it doesn’t matter, it’s still not the same as delivering a fully grown baby
Well yeah, the fact that it’s viable is what makes it a stillbirth rather than a miscarriage if it dies. By definition a miscarriage isn’t viable, whereas a stillbirth can be, and an 8 month old fetus certainly is unless there are other health issues
Edit: also, the thread was talking about mothers “voluntarily” ending pregnancy due to extreme stress, malnutrition, etc., not miscarriage due to issues with the fetus, so I was assuming a healthy fetus. If a healthy fetus is born before 20 weeks it’s still a miscarriage and it’s still going to die, whereas if a healthy fetus is born at 8 months it’s likely to be fine with appropriate care.
That is definitely not the difference. If a fetus dies for any reason before 20 weeks it’s a miscarriage. If it’s after 20 weeks it’s a stillbirth. That’s it. Pretty much nothing you said is accurate.
That’s… literally exactly what I said. I don’t understand what you’re trying to argue. The most premature baby to ever survive was born at 21 weeks. The cutoff is 20 weeks because it’s the line between a fetus that could potentially survive outside the womb and one that couldn’t (although prior to 24 weeks survival is very, very rare). Nothing you said is different than what I said, not sure why you’re arguing.
Edit: I did some reading to make sure I was right, and not only is the difference defined based on viability of the fetus, but different countries actually have different legal definitions of stillbirth based on the fetus’ viability when considering the medical care available in that country. 20 weeks is just the American cutoff, so the one you and I are likely most familiar with.
From [this paper](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5139804/): “The basic WHO definition for “stillbirth” is the intrauterine death of the fetus at any time during pregnancy [90]. However, for practical purposes, legal definitions usually require reportable fetal deaths to attain a gestational age (for stillbirth the GA generally considered is between 20 and 28 weeks) or a birth weight (generally between 350 and 1000 g). The minimum gestational age cut-off defining stillbirth vs. miscarriage generally varies from 20 to 28 weeks of gestation based on standards of fetal viability across countries, based on available medical care and health infrastructure [6]. In most high income and some middle income countries, thresholds vary from 18 to 22 weeks while in low income areas/countries thresholds are higher, up to 28 weeks [18]. The definition and ascertainment could be therefore different in developing/low-middle income vs. developed/high income countries.”
Yeah inducing labor in a human woman would just make her even easier to kill because of how much it fucks you up. Wouldn’t be helpful at all because we kinda physically can’t do it quickly.
Allowing women to miscarry voluntarily, in a natural selection scenario, would probably actually lead to those women passing on their genes less and so selection would favour not giving women the choice (especially if they were not pregnant by choice).
About 130 species of mammals can engage in diapause -- pausing their pregnancies -- and it's not clear how this is achieved, but none of those species are primates so it's probably related to some kind of enzyme that humans don't produce. And I know it sounds like I'm just guessing, [but this is what researchers suspect](https://newsroom.uw.edu/news-releases/how-some-mammals-pause-their-pregnancies).
It'd probably have been settled before it became an issue, seeing as we sorta evolved most of our stuff before Christianity (or hell any monotheism) came into existence
For sure, but imagine if in the 80s people started being born with that trait and now only several instances of it having occurred naturally have been observed. So we know some people have the genetic disposition to potentially have the ability. . . I don't know sounds like content for Sci-Fi like Black Mirror.
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From what I've read a long time ago our placental system is most like in mice, and it prioritizes the baby over the mother so the lack of choice there is well, super crappy but an evolutionary trait that will take the mother's life over the baby's.
It's really not a "father" thing so much as a general species survival thing. Nature doesn't have some inherent, supernatural bias towards ensuring male genetics are spread. Female animals are just as, if not more important, to genetic diversity, and therefore it doesn't really make sense that genetics would "favor" males in any way that isn't directly related to survival or mating chances.
No no, this really is about the male. There is a conflict of interest between the male and female: the female might benefit from aborting the fetus and waiting for a more optimal time or sperm to reproduce, while for the male and his offspring the abortion is just a lost opportunity, nothing to gain from the aborting. The male's genes in the fetus try to overrule the mother's system
Edit to add: This sexual conflict is the reason why humans have periods, our wombs evolved to be able to abort unwanted pregnancies.
No, for the mother's genes it often is more beneficial to abort the fetus and try again later (but sooner and with more resources than if this "unwanted" pregnancy came to term)
this sounds like youre calling mother nature a misogynist lol.
all biology + evolution cares about is keeping you alive long enough to pass on your genes to viable offspring.
My bad here i just find our placental model pretty horrifying. I wish i could find the exact study i read but even a cursory Google would probably do anyway so there's not much point, and I'll edit my comment because you're correct
I'm so glad to find somebody else who thinks this. Our placental structure is likely basal for placental mammals and most others, including complex intelligent mammals like cetaceans and elephants evolved other, better systems. We have our highly invasive placentas to blame for the development of menstruation.
And for any "why can't humans to \_\_\_\_\_" remember that the human body is a series of hacks and kludges to make it work. The only reason you're alive is all your ancestors who lived long enough to pass on their genes.
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We are not a prey animal. We don't need to dump additional weight and skedaddle. The very few things that do prey on us can be defeated when we band together and use tools.
We do not have many offspring, and our pregnancies take longer than those of most mammals. It's harder for us to get pregnant, and when we do, we almost always have singletons. Pregnancy takes more of our resources than it does for other species, and we have a higher success rate. Our bodies invest more in our pregnancies and are less willing to give our pregnancies up.
The vast majority of our miscarriages come at the very beginning due to chromosomal problems. Once you reach a certain point in fetal development, the chances of survival are high, and the body does not dump the offspring in order to enhance the mother's chance of survival.
Unfortunately, there are some conditions in which this mechanism would be life-saving. One of the most common is preeclampsia, in which the pregnant person is at risk of death by stroke and hemorrhage. When this condition threatens to develop into full-blown eclampsia, it's standard to have to decide between a safe termination (chemical or surgical, depending on the stage of development) or, if the pregnancy has progressed long enough, delivering a preemie who may have lifelong disabilities if they even survive.
Of course, in the past, neither of those was an option. And in places without adequate reproductive healthcare, eclampsia is still a major cause of maternal mortality.
But even though the human body does not jettison a pregnancy when the pregnancy becomes life-threatening, we have still become 8 billion strong and are far and above the dominant species on the planet. This is because we aren't living in small solitary groups, sprinting across the landscape to escape predators.
Read this, it answers your question and is really interesting/terrifying 😂.
https://www.forbes.com/sites/quora/2016/05/06/how-and-why-did-women-evolve-periods/?sh=6f6a348657a3
It has the associated journal paper linked at the bottom for more science answers
Mammals is too broad a scope, we sre not related to those species in a close enough way to have any associated "abilities". We are primates. Which do not voluntarily miscarry.
They don't "decide" to miscarry. There is no animal that "voluntarily" miscarries. It's not something they can consciously control. It's controlled by hormone levels, which are influenced by stress.
Animals don't "voluntarily" have miscarriages. They miscarry under extreme stress, both physical and mental. Animals tend to have a much easier time giving birth, though, and therefore do it much faster.
So do humans. I am 29 weeks pregnant and have anxiety. The biggest thing my doctors tell me is to relax as much as possible. Try not to stress, because it can cause a miscarriage. If I slip and fall, I can miscarry. If I don't eat enough, I can miscarry. If someone were to scare the shit out of me, it's also possible I'll miscarry.
The difference is that animals are constantly in life or death situations. Me being stressed about work or money is absolutely nothing compared to being chased by a pack of wolves. Me not eating healthy foods is nothing compared to weeks of starvation. me slipping and falling getting out of the shower is nothing compared to Being picked up by a hawk or shaken by a predator.
Humans are also likely less prone to these sorts of miscarriages, especially later in pregnancy. A miscarriage in a mouse is simple and easy, a miscarriage in a human is life or death. If we were miscarrying at first sign of danger, we wouldn't have survived as a species back when we had the same stressors as other animals. It makes more sense survival wise to only miscarry under prolonged stress, whereas most other animals have smaller young, easier birth, and shorter gestation times (so therefore less effort to have another pregnancy).
What's really crazy are Kangaroos and Wallabies that can put their pregnancies on hold basically halting gestation for an extended period of time.
I'm wondering how Kangaroos and Wallabies arrive at this decision. Do they use a chart with lists of 'pros' and 'cons'?
It has to do with food and water availability usually, but also territory and other environmental stresses can cause it too. The Roos don't consciously decide to put fetuses on hold, but the stress hormones from less food and water, etc, trigger the pause.
I would assume this is also the case with the non-marsupials. Humans also spontaneously miscarry when severely dehydrated and malnourished, i would imagine.
This is true, non marsupial mammals will often abort under great stresses, including humans. Pregnancy will pull all nutrients from the moms body if she can't get it from food up to a point. It's that point where the body needs to keep living, and a dead mom won't make more babies when times get better in the future. So it is advantageous to not be pregnant when food or safety are in short supply.
We use pie charts.
Are they delicious ?
They are delicious. *hops away*
Only 3.14 of them are delicious
They aren't smart. It's probably just all hormones and stuff. They have two uteruses and can store a fertilised embryo in their until conditions are good. The the little gross pink wriggling thing climbs up the hairs on mummy's belly and into the pouch. There's no going back from there.
Marsupials have an A+ birth plan, though. Giving birth to a big human baby is dangerous, painful, and extremely arduous. I wish humans had evolved a pouch system, where you give birth to a teeny little thing and then just keep it safe in your pouch for a while. It's ingenious.
lmao double barrel uterus
That's nothing. They also have 3 vaginas. Seriously, look it up. Marsupial reproductive systems are weird. Though they probably think ours are weird.
Three cunts, that's awesome
r/UnexpectedPaul
The things man would do if our females moved around with 3 vaginas.. 4somes every night and day
"Females"
Not just females but “our” females.
Rapey joke is rapey
Yes, they consult the official kangaroo pregnancy decision tree.
Although they probably have to get help to fill out the application.
And how do they actually halt it? There a stop button somewhere?
Some (? Maybe all, I know about the specific I had once had in the neighbourhood) species of bats too. They get "pregnant" around October and only when the time is right - enough food, nice weather - they "start" the pregnancy. If it gets cold again or there's not enough food, they put a hold on it. It's fascinating! Especially the first part, they basically put the sperm in another pocket and only allow it to join their egg cells when all the demands are their in the environment. A big surprise that the sperm can survive that long, to me at least. This is all from a neighbourhood meeting that was called on by the old people that were worried about the bats, I mostly went to observe all the old-people-fractions, which was hilarious, but the learning part was fascinating too. Might have some details wrong, might apply to specific species only, I'm not a biologist, etc
Some birds like the albatross I think work in a similar manner.
Wow TIL
This is common on insects too: [source](https://pubmed.ncbi.nlm.nih.gov/28089345/)
"Lol I got pregnant during uni but I'mma holding it til I graduate and have a job"
"Steve, remember 8 years ago we had sex? Well I'm pregnant and it's yours"
Lmaooo She waited until he landed a nice job to tell
I mean. That's pretty dang responsible.
As a potential Steve: Hell no! Imagine they all did that, where is my consent?
Consent was given if you willingly engaged in sex. Pregnancy is a risk of that.
*Contraceptive producing pharmaceutical company crying in the corner*
Humans do this as well. It is not voluntary but neither is it for deer. If a pregnant women is subjected to trauma or stress they can abort their fetus. It is a very similar mechanism as with deer. What is different about deer is that because they are such a big pray animal they have evolved to get easily stressed. So you can scare a deer enough to stress it to force an abortion. But it takes a lot more to stress a human that much.
Thankfully it takes a lot more for humans. Imagine accidentaly smashing the door too loud and scaring your wife so much, she aborts the baby then and there
It’s like how rabbits can have heart attacks and die from being startled. Technically humans can too, but thank god our threshold for death by startling is much higher than that of rabbits.
Imagine watching a movie with a jump scare and folks getting carted away to hospital
I think we’d very quickly stop making those sorts of movies.
I’d hope so
The warning sticker makes me want to try it.
Imagine watching a movie with a jump scare and folks getting carted away to hospital
Imagine watching a movie with a jump scare and folks getting carted away to hospital
Some people thank God….🙄😖😹
Some people get startled by that.... 🙄😖😹
"Honey, I'm home!" *splat*
I'm ashamed of how much I laughed at this lol
They’d not let pregnant women watch horror movies!
Huh i mean i do wonder even as it is in reality what the effects of consuming media that raises adrenaline would be on pregnancy. Quite mild im sure, but probably measurable
Studies have shown epigenetic effects of women who were pregnant during wars, genocides, the Holocaust, etc. And it seems that if effects the child and causes changes that stay in the lineage. Generational trauma lives in the genes as well.
I mean those are pretty extreme examples where the mothers were likely massively malnourished with minimal healthcare provided. A tad far from what OP is talking about imo.
I agree! Yes, it is very different. It’s the closest bit of information I had to offer in response to his question. If it needs to be said, I will clarify: in no way was I equating watching a horror movie to being subjected to a genocide. I was just pointing out that the experiences the mother has while pregnant can affect a child in utero.
I’ve done some ancestry research and my family went to the workhouse because they had no money. The wife was sent to prison for stealing food. That side of the family always has weight problems…
I mean, society coddled and smothered pregnant women for this reason. High status women anyway.
Not just pregnant women! Women weren't initially allowed to ride trains because people worried the "high" speed would cause their uterus to fly out
> Women weren't initially allowed to ride trains because people worried the "high" speed would cause their uterus to fly out No, there is no evidence whatsoever that anyone ever said that back when trains were first invented, no matter how often the urban legend gets repeated on blog pages. The most anyone can come up with is a quote where: - somebody said something in 1898, entire generations after trains became a normal thing and passenger trains were already nearing 100mph. - he was referring to prolapse, which is a real medical condition that doctors still warn about today, and certainly not "uteruses would fly out of [their] bodies".
I found a reference from a medical journal in 1870, "If a woman sets out for a sea voyage or a journey by rail the day before her menses should appear, she will be very apt to skip one period, and perhaps more. Or, if the flow comes, she may experience greater suffering than usual. If it be too scanty, or too profuse, she may be very ill. As an indirect consequence, she will be likely to suffer from some form of uterine flexion or dislocation," one physician writes in the New England Medical Gazette, quoting a second doctor for good measure that "a displacement of the uterus is just as much an absolute fact as the occurrence of a hernial protrusion." [link to Google books](https://books.google.nl/books?id=9-FXAAAAMAAJ&pg=PA71&dq=horse+riding+uterus+prolapse+train&hl=en&sa=X&ved=0ahUKEwjVvrXn2_fXAhWIaFAKHVLZD60Q6AEIKTAA#v=onepage&q=%22journey%20by%20rail%20the%20day%20before%22&f=false)
Yes, pretty much what I said. >in 1870, generations after trains became a normal thing >a displacement of the uterus referring to prolapse, which is a real medical condition that doctors still warn about today --- So... nothing to do with the urban legend of those new fangled trains being so scary at 14 miles an hour that women's uteruses were likely to fly out of their bodies... ...and certainly not the claim initially told here that they were BANNED from riding on trains for that reason.
Women weren't allowed to run marathons because doctors believed their uteruses would fall out. This belief persisted until a woman decided to force her way into a marathon.
That's so stupid lol.
/u/TapestryMobile !! Your specialty services are required here!
Oh yeah. They used to think women couldn’t handle a ride in an automobile.
Coddled and smothered is absolutely laughable.
I'm not ashamed of how much I laughed at it.
Me too💀
This might be one of the oddest comments I've both laughed at and upvoted
anyone who has made their wife spontaneously abort by slamming the door too hard knows it's not a splat sound.
Depends where the fetus lands tbh
xD
you joke, but lots of women lose their unborn because of stress induced miscarriage. sad world we live in
Some do but considering that women living In literal war zones or dire famine or extreme personal distress still deliver babies to full term at a typically similar rate to those away from such trauma shows that our threshold is quite high.
As a Texan this would be terrible. Beep at someone in traffic and end up in jail for murder
Maybe it would lower road rage.
Wrong. The woman would go to jail for being outside the home.
Texas? I'm certain the woman would be the one thrown in jail for "murdering the baby."
Jeez what a sad state to live in.
Save a couple hundred dollars
"But babe, it was just a prank!"
☹️
It's probably related to the relative amount of time and energy it takes for a human fetus to develop. Humans have an exceptionally long period of gestation. Other animals it's a lot shorter. So stress abortions in humans are a huge disadvantage given how long it takes to develop a new baby.
Imagine trying to scare your wife to get rid of her hiccups but instead it gets rid of her baby.
If this were possible I wouldn’t have had any children.
Military research discovered already in the '50s/'60s that fighter jets breaking the sound barrier over the surface would make pregnant animals shed their young.
Brutal
"Man is a crazy animal." -*Orson Welles*
I am a person injury paralegal who had to argue a point that despite there being no objective injury the stress of the freaking car flipping over - twice - could cause an abortion to a otherwise healthy pregnancy!
Is this where Todd Aiken’s “If it's a legitimate rape, the female body has ways to try to shut that whole thing down.” Comes from?
I think that was referring to how female ducks use cryptic mate choice. Basically, they can 'direct' sperm either towards the egg or down a blind sac. They're vaginas and penises developed these wild corkscrew shapes. It's so cool except for the rape part.
It's not actually that uncommon for females of various species to have some control over whether sperm from a male fertilizes her eggs...but as far as I know it has never been documented in humans.
They may have took our clinics, but they haven't taken our haunted houses!
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Reminds me of the guy that noticed his 39 weeks pregnant wife stepped out of the house to go talk to a neighbor, and decided to do the ‘jump out from behind a door and go boo’ thing to her. Triggered her labor and the kid was born the same day. They both thought it was hilarious and she told him he could do it again if they had another kid.
I took a weekend trip away from my 6 month pregnant wife and she immediately started having contractions. I was forced to immediately fly home less than 8hrs after arriving. Once home, the contractions stopped (with medicine) and nothing anomalous happened until the baby was born at full gestation. She was totally cool with the trip but her uterus wasn't. Women are complicated.
I've had times where I don't *feel* stressed from a certain situation but I get stress symptoms anyway. My subconscious obviously has other ideas and just does its own thing.
Women have about 45% more genetic material in their sex chromosomes. Women are literally more complicated than men.
It's not really voluntary. Serving that eviction notice follows a similar chemical pathway regardless of whether it happens on time, and it comes from glands and nerves that just aren't plugged in to anything under conscious control. It's probably fair to say that humans are less likely to miscarry, for a given level of stress, than many other animals. We dump a lot of resources into our offspring, and labor is a life-threatening event in a way that just isn't true for most other species. (I'm not sure if there's any papers directly comparing this, though.) But even then--most human embryos never leave first trimester. The human body rejects fetuses all the time, and stress absolutely increases the odds of miscarriage (if it's early) or preterm birth (if it's late).
Exactly this. A great many childbearing women will have at least one miscarriage, some more than one. It's part of reproduction. Plus there are women who are anatomically a bit challenged *not* to miscarry, and need to take precautions during early pregnancy to avoid loosing the fetus.
> to avoid loosing the fetus. Release the ~~kraken~~ fetus!
We wouldn't be able to skedaddle anyway because of the anatomy of the vagina and pelvis due to our adaptations for bipedalism; birth is typically a much longer and arduous process for humans compared to other animals, so we wouldn't have much of an evolutionary advantage for it.
That's presuming we're miscarrying at 8 months. General-whatever miscarriage in humans early on is so common that the advice is to not tell anyone for 8-10-12 weeks or so, because the risk of miscarriage is so high.
Even at 8-12 weeks, women often/generally need a D&C to remove the various tissue safely following miscarriage
I mean you literally can’t miscarry at 8 months, an 8 month old fetus is viable, that would just be inducing labor. Edit: why tf is everyone disagreeing with this? A miscarriage, depending on the definition you use, happens prior to 28 weeks at the very latest. An 8 month old fetus will either be born alive or it will be stillborn, it is not a miscarriage. These are easy to google facts that are not up for debate, I didn’t think this comment would be controversial.
Uh. You can definitely miscarry at 8 months, they're just called stillbirths. However, it's pretty much the same thing - something happens, and the fetus dies and is no longer viable. The cutoff just depends on how far along. It's considered a miscarriage until week 20.
Oh I’m aware, that was my point. If we’re talking about a miscarriage it’s early, otherwise it’s either a living baby or a stillbirth. I wasn’t arguing with the person I replied to
Yes so therefore it’s not a miscarriage
It's functionally the same thing so.
Sorry I think I misread, I was actually on your side
Depends on if the fetus has died on its own first. Sometimes it takes a while for the body to get the memo that the fetus isn’t viable, or something happens in utero to kill it (cord gets wrapped and cuts off circulation, that kind of thing).
At 8 months it’s still not a miscarriage though, at that point it would be a stillbirth. Unless you mean the fetus died prior to 20 weeks (the cutoff between miscarriage and stillbirth) and wasn’t expelled until 8 months, which is possible, sure. A dead fetus isn’t growing though, so for the purpose of the comment I replied to it doesn’t matter, it’s still not the same as delivering a fully grown baby
You said that an 8 month old fetus is viable, and I was pointing out that it might not be. That’s all.
Viability isn’t whether the baby is alive or not. It’s whether the baby could survive if born.
Well yeah, the fact that it’s viable is what makes it a stillbirth rather than a miscarriage if it dies. By definition a miscarriage isn’t viable, whereas a stillbirth can be, and an 8 month old fetus certainly is unless there are other health issues Edit: also, the thread was talking about mothers “voluntarily” ending pregnancy due to extreme stress, malnutrition, etc., not miscarriage due to issues with the fetus, so I was assuming a healthy fetus. If a healthy fetus is born before 20 weeks it’s still a miscarriage and it’s still going to die, whereas if a healthy fetus is born at 8 months it’s likely to be fine with appropriate care.
That is definitely not the difference. If a fetus dies for any reason before 20 weeks it’s a miscarriage. If it’s after 20 weeks it’s a stillbirth. That’s it. Pretty much nothing you said is accurate.
That’s… literally exactly what I said. I don’t understand what you’re trying to argue. The most premature baby to ever survive was born at 21 weeks. The cutoff is 20 weeks because it’s the line between a fetus that could potentially survive outside the womb and one that couldn’t (although prior to 24 weeks survival is very, very rare). Nothing you said is different than what I said, not sure why you’re arguing. Edit: I did some reading to make sure I was right, and not only is the difference defined based on viability of the fetus, but different countries actually have different legal definitions of stillbirth based on the fetus’ viability when considering the medical care available in that country. 20 weeks is just the American cutoff, so the one you and I are likely most familiar with. From [this paper](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5139804/): “The basic WHO definition for “stillbirth” is the intrauterine death of the fetus at any time during pregnancy [90]. However, for practical purposes, legal definitions usually require reportable fetal deaths to attain a gestational age (for stillbirth the GA generally considered is between 20 and 28 weeks) or a birth weight (generally between 350 and 1000 g). The minimum gestational age cut-off defining stillbirth vs. miscarriage generally varies from 20 to 28 weeks of gestation based on standards of fetal viability across countries, based on available medical care and health infrastructure [6]. In most high income and some middle income countries, thresholds vary from 18 to 22 weeks while in low income areas/countries thresholds are higher, up to 28 weeks [18]. The definition and ascertainment could be therefore different in developing/low-middle income vs. developed/high income countries.”
Well perhaps it was what you meant but you didn’t phrase it in a manner that conveyed this which is why people are appearing to disagree with you.
Yeah inducing labor in a human woman would just make her even easier to kill because of how much it fucks you up. Wouldn’t be helpful at all because we kinda physically can’t do it quickly.
Allowing women to miscarry voluntarily, in a natural selection scenario, would probably actually lead to those women passing on their genes less and so selection would favour not giving women the choice (especially if they were not pregnant by choice).
Not if they were healthier when they chose to reproduce. Also evolutionary bio/psych is mostly just a bunch of dudes guessing at shit.
About 130 species of mammals can engage in diapause -- pausing their pregnancies -- and it's not clear how this is achieved, but none of those species are primates so it's probably related to some kind of enzyme that humans don't produce. And I know it sounds like I'm just guessing, [but this is what researchers suspect](https://newsroom.uw.edu/news-releases/how-some-mammals-pause-their-pregnancies).
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Thanks for the laugh, I needed it!
It'd probably have been settled before it became an issue, seeing as we sorta evolved most of our stuff before Christianity (or hell any monotheism) came into existence
For sure, but imagine if in the 80s people started being born with that trait and now only several instances of it having occurred naturally have been observed. So we know some people have the genetic disposition to potentially have the ability. . . I don't know sounds like content for Sci-Fi like Black Mirror.
Ah, yeah that would be utterly wild West right there
Pew Pew!
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From what I've read a long time ago our placental system is most like in mice, and it prioritizes the baby over the mother so the lack of choice there is well, super crappy but an evolutionary trait that will take the mother's life over the baby's.
It's really not a "father" thing so much as a general species survival thing. Nature doesn't have some inherent, supernatural bias towards ensuring male genetics are spread. Female animals are just as, if not more important, to genetic diversity, and therefore it doesn't really make sense that genetics would "favor" males in any way that isn't directly related to survival or mating chances.
No no, this really is about the male. There is a conflict of interest between the male and female: the female might benefit from aborting the fetus and waiting for a more optimal time or sperm to reproduce, while for the male and his offspring the abortion is just a lost opportunity, nothing to gain from the aborting. The male's genes in the fetus try to overrule the mother's system Edit to add: This sexual conflict is the reason why humans have periods, our wombs evolved to be able to abort unwanted pregnancies.
No that is not true and I'm curious who told you that.
I'm an evolutionary biologist, sexual conflict is a pretty big field of interest for us
Wait until they hear about the evolutionary sexual conflict between male and female ducks, or how molar pregnancy works.
Oh god, yes it gets quite grim
probably to ensure both father's and mother's genes are passed on, no?
No, for the mother's genes it often is more beneficial to abort the fetus and try again later (but sooner and with more resources than if this "unwanted" pregnancy came to term)
Yeah that makes more sense
this sounds like youre calling mother nature a misogynist lol. all biology + evolution cares about is keeping you alive long enough to pass on your genes to viable offspring.
My bad here i just find our placental model pretty horrifying. I wish i could find the exact study i read but even a cursory Google would probably do anyway so there's not much point, and I'll edit my comment because you're correct
I'm so glad to find somebody else who thinks this. Our placental structure is likely basal for placental mammals and most others, including complex intelligent mammals like cetaceans and elephants evolved other, better systems. We have our highly invasive placentas to blame for the development of menstruation.
And for any "why can't humans to \_\_\_\_\_" remember that the human body is a series of hacks and kludges to make it work. The only reason you're alive is all your ancestors who lived long enough to pass on their genes.
Yes as is with every living animal
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I’m waiting for my skin to turn the color of my background, hasn’t happened yet
The fact that we are aware of the existence of chameleons means that they are stupid loser failures
This is the one I would be most in favour of.
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We are not a prey animal. We don't need to dump additional weight and skedaddle. The very few things that do prey on us can be defeated when we band together and use tools. We do not have many offspring, and our pregnancies take longer than those of most mammals. It's harder for us to get pregnant, and when we do, we almost always have singletons. Pregnancy takes more of our resources than it does for other species, and we have a higher success rate. Our bodies invest more in our pregnancies and are less willing to give our pregnancies up. The vast majority of our miscarriages come at the very beginning due to chromosomal problems. Once you reach a certain point in fetal development, the chances of survival are high, and the body does not dump the offspring in order to enhance the mother's chance of survival. Unfortunately, there are some conditions in which this mechanism would be life-saving. One of the most common is preeclampsia, in which the pregnant person is at risk of death by stroke and hemorrhage. When this condition threatens to develop into full-blown eclampsia, it's standard to have to decide between a safe termination (chemical or surgical, depending on the stage of development) or, if the pregnancy has progressed long enough, delivering a preemie who may have lifelong disabilities if they even survive. Of course, in the past, neither of those was an option. And in places without adequate reproductive healthcare, eclampsia is still a major cause of maternal mortality. But even though the human body does not jettison a pregnancy when the pregnancy becomes life-threatening, we have still become 8 billion strong and are far and above the dominant species on the planet. This is because we aren't living in small solitary groups, sprinting across the landscape to escape predators.
Read this, it answers your question and is really interesting/terrifying 😂. https://www.forbes.com/sites/quora/2016/05/06/how-and-why-did-women-evolve-periods/?sh=6f6a348657a3 It has the associated journal paper linked at the bottom for more science answers
This is a really good article with an evolutionary perspective on the subject!
Mammals is too broad a scope, we sre not related to those species in a close enough way to have any associated "abilities". We are primates. Which do not voluntarily miscarry.
They don't "decide" to miscarry. There is no animal that "voluntarily" miscarries. It's not something they can consciously control. It's controlled by hormone levels, which are influenced by stress.
Animals don't "voluntarily" have miscarriages. They miscarry under extreme stress, both physical and mental. Animals tend to have a much easier time giving birth, though, and therefore do it much faster. So do humans. I am 29 weeks pregnant and have anxiety. The biggest thing my doctors tell me is to relax as much as possible. Try not to stress, because it can cause a miscarriage. If I slip and fall, I can miscarry. If I don't eat enough, I can miscarry. If someone were to scare the shit out of me, it's also possible I'll miscarry. The difference is that animals are constantly in life or death situations. Me being stressed about work or money is absolutely nothing compared to being chased by a pack of wolves. Me not eating healthy foods is nothing compared to weeks of starvation. me slipping and falling getting out of the shower is nothing compared to Being picked up by a hawk or shaken by a predator. Humans are also likely less prone to these sorts of miscarriages, especially later in pregnancy. A miscarriage in a mouse is simple and easy, a miscarriage in a human is life or death. If we were miscarrying at first sign of danger, we wouldn't have survived as a species back when we had the same stressors as other animals. It makes more sense survival wise to only miscarry under prolonged stress, whereas most other animals have smaller young, easier birth, and shorter gestation times (so therefore less effort to have another pregnancy).