# Should immortal women have periods?

So, in my world, I try to play the "immortality" trope with twists that make it suitable for my imagination.

So, to understand the question, let me give you precise details:

• These immortals are 100% human, no vampires and such.
• This also implies that the source of immortality is physics-based, rather than chemistry or biology.
• The world we are talking about is an afterlife of some kind. Immortals here are immortals because they died in another world, and "arrive" to this world and live in their most recent healthy shape.
• People can die but they resurrect somewhere within the universe, nullifying every change on their bodies happened since their "initial" arrival.

TL;DR - these immortals are, let's say, people for who the "rules of time" do not apply appropriately, preventing them from aging.

Okay, this is a heavily disputable concept, please forgive me, I hadn't gone through every consideration yet. In fact, I ask this question to resolve one: fertility.

Needless to say that no afterlife can prevent becoming Hell, if its never-aging inhabitants can reproduce. Infinite life span implies several factors becoming infinite, too: this includes the potential amount of offspring. Well, not in the case of women, but let me bring it out later.

So, given this fact, I decided to make my immortals unable to make children. To avoid disturbing the human body's regular operation as much as possible, I decided to make it obvious at one single point: the merge of...those two cells, you know.

As a result, every fertilized ovum disintegrates immediately. I guess the amount of energy released from such a small mass can be practically unnoticeable, so it's fine.

This brings up a new consideration, though: the presence of ovum within immortal females' body is pointless. I'm really not sure if I should do something with it. The following outcomes are possible:

1) During 'arrival', all ovum disappears. This would cause a huge change in female hormone balance, if I know correctly.

2) Their amount is unchanged, but women have no periods. That would again, change the hormone balance, I'm almost sure of it, at least in the aspect that stopping periods is impossible without hormonal changes.

3) Ovum coming out disintegrates immediately, regardless of fertilization. This would prevent the need of hygienic precautions during "those" days, increasing comfort, but may possibly feel far-fetched for an audience. I want to make the rules to be as natural as possible.

4) No change applied in the matter. It is the most natural way of handling this question, but would imply that, in case of a biologically 20 years old woman, that decades later, when she's still 20 biologically, but 50 chronologically, she's out of these cells, inducing menopause. I repeat: menopause, in a biologically 20 years old woman. Not sure if I can (or even want to) handle this situation, as it implies hormonal changes.

Sorry for the long post, it was actually a portion of my worldbuilding process. It's hard to include "magic" while also trying to keep authenticity.

Is there a truly optimal method to handle this question?

• Comments are not for extended discussion; this conversation has been moved to chat. – Tim B Nov 23 '16 at 11:37
• I've changed the warning at the start since I don't think there is anything here that qualifies as NSFW no matter how some people may treat the subject. It's not like you are warning them of anything that wasn't obvious from the question title. – Tim B Nov 23 '16 at 11:42
• If you have a source of people (people dying before getting there) and no sink, you'll eventually have unbounded population growth anyway. Plus, the babies can't age, so how would a fertilized egg even grow to become a baby? – Scott Whitlock Nov 23 '16 at 17:19
• What is that "Mod Note" doing there at the top? I thought this was a community for adults who know the basics biological facts about being human? Seriously, it's embarrasing. Please remove it. – Felixyz Nov 24 '16 at 8:40
• Possibly relevant: gladwell.com/john-rock-s-error — tldr: women in a state of nature menstruate far less often than you might think. – Anton Sherwood Nov 24 '16 at 9:28

You can go through with a normal cycle, menstrual cycle runs as normal, menopause runs as normal at a certain age, after which no more periods. You can say that the immortality means that the normal menstrual cycle keeps running forever.

All these things have hormonal consequences, and as such consequences for the body, if you want to keep people "young" forever, I'd suggest maintaining the cycle indefinitely.

However, just as there are apparently no toilets on the Starship Enterprise, it doesn't matter unless it matters for the story, you can probably ignore it completely. Just a statement that the process that made people immortal made them infertile without making too much of the process or why they're infertile.

Terry Pratchett takes this option in Strata, people who've had the longevity treatment give up the opportunity to have children. He doesn't say how or why, it is just a statement early on in the book.

We wonder if the short-lifers live more vividly, and dread learning that they do, because we gave up the chance of children.

If you're going to mention it at all then it's going to blow up to be a big thing. 1000 years of infertility, heavy periods, bad cramps, and struggling with iron deficiency is going to make an industry for elective hysterectomies that dwarfs the rest of your medical industry.

• What is the point of hysterectomy if people "restart" back as what they were then they first arrived there? People can die but they resurrect somewhere within the universe, nullifying every change on their bodies happened since their "initial" arrival. – Mindwin Nov 23 '16 at 12:36
• @Mindwin, that's what makes the industry so big, people will have to keep getting it redone every time they reset for some reason. – Separatrix Nov 23 '16 at 12:38
• I like the reference to the book where one of main characters is world builder by profession. – Crowley Nov 23 '16 at 12:51
• @Separatrix yeah, one might argue the existence of the period may in and of itself be a form of needless suffering for immortals. Might as well throw the process away and just have the necessary hormones perpetually exist in the bloodstream. – The Great Duck Nov 24 '16 at 4:47
• @corsiKa, I don't want to take a bath, I need a toilet ;) – Separatrix Nov 24 '16 at 17:32

Well, human women have all their eggs pre-made -- they are born with a finite number of eggs and that's what they will ever have. If you want immortal women to have an infinite number of periods you will have to alter their physiology significantly; as a consequence, since you have already altered their physiology, you may as well introduce a patch which allows them to choose whether they want to be fertile or infertile at any given time.

• This. Even if they have periods, they'll have a finite number of them. – SRM Nov 23 '16 at 5:59
• @SRM nope: People can die but they resurrect somewhere within the universe, nullifying every change on their bodies happened since their "initial" arrival. - that includes egg usage with periods. – Mindwin Nov 23 '16 at 12:37
• This also means that they have no memories of their past existences, doesn't it? So they are no really immortal, they just have multiple independent existences. – AlexP Nov 23 '16 at 12:39
• I don't see any obvious reason why women who have exhausted their egg supply can't have continued menstrual cycles, although this may require some genetic tinkering. In mortal women, menopause is not triggered by exhaustion of the egg supply, but rather by changes in hormonal levels. – WhatRoughBeast Nov 23 '16 at 13:07
• @AlexP of course they have memories of their past lives. From birth to the afterlife, they remember everything after each "death". So, yup, I was a bit wrong, the memories are not eradicated biologically. – Katamori Nov 23 '16 at 17:16

# No; your immortals will not have cyclical or life-long hormone changes

Why would immortal women who cannot have children need periods? The answer, as you know, is that they don't; therefore they shouldn't have periods.

There are a variety of hormonal processes that happen in humans. Should the immortal men in your kingdom have increasing levels of androgen that cause their testes descend? Of course not, you aren't asking that question, that is just silly. Should men or women who arrive in this place undergo puberty? Should men get male pattern baldness over time? Should women get menopause 30 years after showing up?

Immortality, in the way you are describing it, implies time-freezing the development of a human body to hold people in one state. If that is the case with puberty, male pattern baldness, and menopause, then it is certainly the case with the menstrual cycle as well.

• Sir, you got me with the last paragraph. Another connection between my own rules I missed to discover. Thank you very much! Unless any better answer comes out, I'm ready to accept this one. – Katamori Nov 22 '16 at 21:29
• But if the biological state of a human is frozen when they arrive, would that mean a woman who dies while on her period would constantly be menstruating for all eternity? "Most recent healthy shape" could of course imply that menstruating is not a healthy shape so women would always arrive with non-menstruating bodies. Interpret that as you want. – Philipp Nov 22 '16 at 22:32
• Do the immortals get hungry? Do they get tired? Both are related to biological cycles. If you're time-freezing the development of the human body, do those cycles get frozen out too? -- You can have an intermediate timescale where shorter-term (cyclical) change happens, but longer-term change (menopause, puberty, hair loss) doesn't. As the world builder, you just need to choose if the timescale cutoff is longer or shorter than one month. – R.M. Nov 22 '16 at 23:28
• @R.M. the problem is that I want to keep the possibility of dying in starvation that, if I know well, takes more than one month. – Katamori Nov 22 '16 at 23:42
• @Katamori I agree with R.M. generally, but since immortality is not Magical here, They will still expend energy, if only to exist. Food and Drink are not really Biological Cycles, They are the ways Humans obtain resources they need, primarily to replace what they expend. Death by Starvation is simply the body not having enough energy to keep itself alive. Describing Hunger as a biological cycle is to say not that it goes every month, or even day, but every second, continuously running. Unless they Magically obtain energy from somewhere, they need food (or they break Conservation of energy) – Ryan Nov 23 '16 at 17:21

Having a period can be horrible. Menstrual cramps can cause torturous migraines, piercing cramps, and in the worst cases, blood will almost gush from the woman's vagina. On my cross country team, girls literally had to regulate their diet to ensure they didn't become iron deficient with the combination of running and periods. And sometimes the cramps get so bad you have to just curl up on the floor, wishing for death. Don't give immortal women periods. Periods stop naturally as a woman gets older.

Imagine you had to be tortured every week for eternity. This wouldn't be heaven; this would be hell. Periods aren't that bad for most people, but for a small minority, they are that bad or worse. If you want your afterlife to be a paradise of any sort; get rid of periods for immortals. If you want it even to be a decent half-life, get rid of periods. No one's getting pregnant, so no one should need periods.

• In fact, my world is exactly about the fact that if you're immortal, it can be either heaven or hell on its own. It has benefits, but backlashes too, I think it'd be better not to cut it out solely for the sake of "heaven-ness". Though, in your last sentence you got the matter: without pregnancy, it's pointless. But what about the hormones then? – Katamori Nov 23 '16 at 4:38
• The amount of hormones women get on their periods isn't "normal" - it's elevated compared to the rest of the month. If they had the same level of hormones as when not on their periods, they'd be completely normal. No personality changes. You don't have to make it heaven, but periods every month for eternity is a bit too close to hell. It's not something they can choose, either – J. Antonio Perez Nov 23 '16 at 4:45
• Well, you've definitely made a point. In your aspect, simply making every ovum disappear may not sound as terrible as it was at a first glance. – Katamori Nov 23 '16 at 6:34
• Great! Also - 330,000 joules may sound like a lot of energy, but it's ~150 calories. No biggie. – J. Antonio Perez Nov 23 '16 at 6:35
• Wait sorry miscalculated. It's ~75 calories – J. Antonio Perez Nov 23 '16 at 6:35

Having fertilized eggs disintegrate pretty much goes against your assumption of immortality. Biologically speaking, a fertilized egg is a living organism in its own right. What you're talking about is the mass death of the very young children of immortals.

Of course, you could just let your immortal women go through menopause and be infertile after that. Alternatively, recall that regular human women are born with all of our eggs--(actually, we have them all before we're even born. In real life, these eggs degrade over time, which is why it's harder for older women to have children, even if they haven't hit menopause. If you keep either of these effects, you're capping the number of children each woman can have.

Iboth these mechanisms are too much like aging for you, how about this: An egg is only viable for about twenty-four hours after ovulation anyway. After that it can't be fertilized.* So you could (a) shorten that time, or (b) lengthen the time it takes an egg to travel far enough down the fallopian tube to meet the other cell, or (c) both.

[*Note: probably someone's wondering whether this means a woman can only get pregnant from intercourse within twenty-four hours after ovulation, i.e. twenty-four hours every month-ish, and the answer is no. Prior to ovulation, a healthy woman produces cervical mucus that both provides "swimming lanes" for sperm to get where they need to go and also actually keeps the sperm alive for a matter of days. It varies from woman to woman, but the actual (potentially) fertile window can be around a week.]

There is a much better solution. If the biology of your immortals DNA is the same and it is merely the afterlife, then just have your universe magically transport the fetuses of immortals to people who could've become pregnant but hadn't. Then the child isn't obliterated, the immortals technically had a child, but nobody is aware of it. After all, there are plenty of people on earth. It cannot be hard for your universe to select a random person who almost got pregnant with close enough dna. After all, this is the afterlife we are talking about. Giving it the power to find potential living parents with the correct dna to look like the parents and not cause suspicion wouldn't be that hard. It's just a giant data search, and the children that don't have a place to go yet can just go into stasis. You could even make an arc where the children of immortals that lived on Earth meet their true parents. Or just have nobody know and make it something people throw out as a random potential thought. Like, "the fetus appears to disintegrate, but some believe they are transported to Earth in secret to live out a live before death".

As for the other stuff and cycles... do whatever seems appropriate. Don't make it torturous for people, obviously. Which means that as some answers stated, tone down any painful aspects of it. No need to get rid of it, if you want it in there. Just make it less painful and get rid of any nutrient issues stemming from it. Immortals have no need to eat, so there wouldn't be iron deficiencies. You can just say their bloodstream is perfectly balanced at all times with whatever foods they primarily ate (or whatever was healthiest that they ate). Once again, no need to punish those in starvation. Make it alterable or just have the universe put it in perfect balance. In it's nature, your universe seems to want to produce people with perfect bodies. What they do with them is up to the people; however, some things or the necessity to do them (eating for starters) could be interpreted as a hell at some point. After all, think of when there is no food. Your immortal is eternally starving because the environment has been ravaged by overpopulation of immortals that never stop consuming. If they are time stopped, there is no reason not to assume that their bloodstream is always in the same ratio with things balanced as they were. Get a cut? The blood gushes out but when the cut closes or stops, the blood will refill with the same ratios. They can die, sure. However, the nutrient deficiency shouldn't do it. The blood cell's leaking out should.

Most important of all, if there is no need to bring it up, leave it to imagination. I think most people will be made uncomfortable reading about it. Better to just ignore it if it isn't relevant to the story itself. After all, why would anyone wish to read that chapter about how immortality works for women's cycles. It's kinda weird...

• One of the best answers I've got,thank you very much! – Katamori Nov 26 '16 at 19:58
• @Katamori You're very welcome. I'm glad you like it. – The Great Duck Nov 26 '16 at 21:29

On a completely different scientific tack, there are practices which current-day women can use to regulate their biochemistry and moderate their menstrual cycle naturally (ie without artificial hormones).

These are based on the observation that modern lifestyles (sedentary, calorie-rich, chemical-laden, preservative-filled, psychologically dissociated from the body and daily/monthly/annual cycles in nature) have increased the duration, volume of blood lost, and incidence of abnormalities in menstruation, compared with, say, traditional hunter-gatherer lifestyles.

These practices generally result in a noticeable reduction in the volume of blood loss, sometimes even reducing it to less than the level that the uterus can reabsorb (so nothing comes out), but to achieve complete cessation of menstrual flow requires a level of physical effort beyond what your average woman would be willing to do day in, day out, for thousands of years.

HOWEVER, just the teeniest little magical tweak could give women all the benefits of this practice without needing to spend a couple of hours a day doing Oli Mudras, Uddiyana Bandhas, and the Deer Exercise.

• I think this very definitely needs some references. – RedSonja Nov 25 '16 at 9:07
• @RedSonja, it's simply missing out a detail or two, the key ones being that in the traditional hunter-gatherer lifestyle 1) First onset was later and 2) women were either pregnant or breastfeeding for the majority of their fertile adult lives and hence not ovulating. – Separatrix Nov 25 '16 at 14:30
• Actually the key ones for volume of blood loss are absolute calorie intake, percentage calories from animal products, and physical activity level. First onset being later is a result of those constraints, and lower menstrual blood volume in general is because of the resources being required to maintain the woman's body in that lifestyle. Time spent pregnant and breastfeeding reduces the frequency, but not the volume. – Jnani Jenny Hale Nov 27 '16 at 7:55

If you really want to avoid dealing with hormones, perhaps you could leverage this tidbit:

People can die but they resurrect somewhere within the universe, nullifying every change on their bodies happened since their "initial" arrival.

Where in addition to this "hard reset" on death, the individuals in this world go through a "soft reboot" periodically, where their body reverts to the initial state, but they don't change location or lose memories. Although this would introduce an entire other set of issues (it'd be pointless to get a tattoo or piercing in this scenario, for instance).

An easy solution would be 2) and get rid of periods entirely. Birth control already exists in our world that slows down a woman's menstrual cycle to only a few times per year. So just take that concept and stretch it out over infinity. Yes, there would be hormone changes. But if you think the issue is important enough to detail (although Separatrix is almost definitely right in that you can ignore this problem entirely if you wanted) then you may as well go all the way and detail the changes.

I'd say it depends on why this setup exists in-universe. If it's some kind of natural phenomenon, it sounds like your universe's magic whisks people away as-is on death, which means the magic is aware of death, which means the magic is aware of life, which means the snuffing out of new life is a response to that new life, which means no changes to physiology. Though the virtual stasis kingledion brings up could mean that they eternally exist at whatever point in their cycle (or menopause) they were at before coming here.

If this is an artificial environment created by some intelligence, and you have already excluded the desire to make it a hell, then it seems likely to assume it is intended as some sort of paradise. This intelligence would then likely have decided that inhabitants should exist at the most enjoyable part of their cycle - and other aspects of their life, so they would probably also be at their ideal weight and strength, in the prime of their life. And they would remain in that state forever.

Also, I just can't let this question pass without mentioning Jack of Shadows, by Roger Zelazny. Everything except this being an afterlife is pretty much straight out of there.

A woman has a monthly cycle because that is what humans have evolved to do. It is pretty trivial to significantly elongate the cycle (once a year, once a decade, only on an external stimulus). Reference this chart:

As you can see, there only really "static" time is early in the cycle when the LH and FSH levels are low, estrogen, inhibin, and progesterone levels are low, and the endometrium isn't actively growing. You can discount the shedding phase after a few days. The eggs are not developing and for a few days, women are as "static" as they get with respect to menstruation. This is basically what birth control pills do. They stabilize the level of progesterone which has a negative feedback on egg maturation endometrial growth by suppressing GnRH and FSH/LH in the brain. Adding estrogen helps prevent break-thru bleeding. High levels of estrogen only would also reduce ovulation, but has shown to have some pretty negative side-effects such as blood clots and stimulating estrogen sensitive tumors. So long as you have some progesterone on board though, the side-effects are minimal. Theoretically a woman could stay on BCPs indefinitely, not taking the 7 "blank" pills at the end, and never experience ovulation and menstruation (the blank pills are just so the woman stays in the habit of taking a daily pill).

Anyway, you can have your immortal women replicate this naturally, such that their endometrium never grows and egg follicles never mature aside from an external stimulus (something that breaks the production of progesterone, allowing GnRH, FSH, and LH to spike) to trigger ovulation or a much longer natural cycle (like how many mammals have estrus only once a year). The monthly cycle is just what humans, masters of their environment, have evolved to, there is nothing that mandates it biologically.

If you simply have your immortal women have NO EGGS they will go into menopause since they will then have big drops in their estrogen levels, which has some negative effects like an increase in atherosclerosis, vaginal dryness, etc. This is why post-menopausal women take hormone replacement.

If there is no requirement for reproduction then your immortal women could just have the uterus atrophy away, so it could never bleed. Basically a natural hysterectomy. They would still need something to stabilize their ovaries for estrogen production though, lest they go into menopause eventually.

Menopause SUPPOSEDLY does not go on forever. It is considered to last for 10 months to 4-5 years after a women has skipped her period for 12 straight months (unfortunately not every women is the same and it can take longer).

You can have your women have their periods until either their eggs run out or your immortality aging finally kicks in. Then have a period of menopause (depending how your immortality ends up working, this could take anywhere from 4-5 years to decades). And then once the uterus has done it's whole shrinking/ageing thing, hormone levels reach a new balanced level and your immortals proceed as normal except this time, no monthly torture sessions.

No periods forever. No menopause forever.

When your immortal reset, they go through the whole cycle again. Same with puberty, male pattern baldness etc.

It would add an extra dynamic to your story if immortals are aware that someone is on 'that time of the cycle' instead of 'that time of the month'. Proceed with caution.

And allowing women to watch men grow bald only for them to have to go through puberty again, would help make up for the decades/centuries of torture you are putting the women through!

• Just had an idea about the reset. You could have a Benjamin button situation... Immortals age normally until they reach a certain point and then reverse age at the same rate. And the age again in the normal way. Like a yoyo :) – EveryBitHelps Nov 23 '16 at 17:16
• @EveryBitHelps I kind of like this idea. – Katamori Nov 23 '16 at 17:18
• @Katamori, it even partially explains the infertility. When you immortal first arrives on the immortal plane they would be fertile but after they run out of eggs they won't be. Then all further periods are just the body doing the natural cycle of getting ready. As someone mentioned before, even if your women have no eggs, they still have a menstrual cycle. So the infertility might just be a symptom of how long they have been immortal not their bodies 20year old age on reset number 42. – EveryBitHelps Nov 23 '16 at 17:35
• I am in year 15 of hot flashes -- sure feels like forever. – WRX Nov 23 '16 at 17:40
• sorry, reality can suck sometimes. – WRX Nov 23 '16 at 17:50

Should women menstruate? Yes, if you want them to have babies in this setting. No, if you don't.

You can have other considerations -- children who have died, arrive as children, making the giving birth to kids unnecessary.

There could be artificial means -- artificial wombs instead.

There could be no children.

To me, this is like the question of do you have a reason for your characters to use a toilet. If you do, write it in. Otherwise, most of us have no need to know if a character urinates or defecates. We'll assume they do.

• I thought it's a bit more than using the toilet, because of the hormonal consequences. – Katamori Nov 23 '16 at 18:05
• fair point, but if you need women to be hormonal -- then write them that way. – WRX Nov 23 '16 at 18:09
• I want to, I definitely want to. But I just can't write something without answering questions that come out of my own mind. I can't concentrate if I leave inconsistency. – Katamori Nov 24 '16 at 2:40
• how about women are hormonal at high moon or high tide or some event and men at low moon or tide? – WRX Nov 24 '16 at 16:28
• Women, like men and children, "are hormonal" all the time. Human bodies use hormones to signal things like hunger, fullness, tiredness, stress, relaxation, fear, happiness, sadness, ... – MissMonicaE Dec 8 '16 at 14:00

Approach no. 1: I don't know if this is what you're looking for... but you could make all the ovums disappear on arrival (your no. 1 option), but still have menstrual cycles.

Menstrual cycles derive from hormones secreted by the cells of the follicles or the corpus luteum, not the ovocytes. These hormone-secreting cells of the follicles enclose the ovocyte prior to its release, and after its release (ovulation) transform into the corpus luteum.

If you could "trick" the follicle into "believing" it has an ovocyte inside, while it has not, and the follicle "ovulates" a blank shot, and then transforms into the corpus luteum... then you would have menstrual cycles. Menstruation would come afterwards, since, there being no ovocyte, there would be no fertilization.

This is not so hard to do. Every hormone is codified on the DNA of every single cell we have. It's epigenetics that make a cell produce the appropriate hormone at the right time... ie, it's epigenetics that makes the cell know when to transcribe each part of its genetic code.

By epigenetically stimulating the DNA transcription of the feminine hormones on the follicle, you would have a menstrual cycle, even without the ovocyte.

Cancers can unlock the DNA transcription of any piece of genetic code there is. A cancerous cell derived from the intestine can, theoretically, produce hormones from the folicle. There is no reason for a folicular cell not to be able to unlock the DNA transcription of estrogen by some epigenetic abherration, since folicular cells are already predisposed (diferentiated) to producing those hormones anyway. All they need is an epigenetic "push"

Also, this would play only until all the finite pre-existing follicles on the woman's ovaries would be exhausted. Then that woman would naturally enter menopause.

Approach no.2 There is another approach. Keep the ovums and the follicles intact. But consider this. Almost every single cell from our organism divides during our lifetime, but the ovocytes don't. The amount of ovocytes is pre-fixed at birth.

Now, "normal" body cells (somatic cells) divide themselves by mitosis, but germ cells (ovums and sperms) aren't produced by mitosis but rather meiosis, which is a process involving 2 cell divisions. After meiosis is completed, the cells can't divide any longer, because they now have half of the DNA, not the whole genetic code.

That's why I mentioned ovocytes and not ovums. Ovocytes are the cells prior to completion of meiosis and ovums are the cells after.

In the case of the ovums, the last division of the meiosis is only completed at the time of fertilization. Yes, that late. The ovum is completing its formation at the time the sperm is entering.

Now, every cell on our organism has a limit to the amount of cell divisions it can undergo... the Hayflick limit, influenced by the length of the telomeres (the "caps") on the chromosomes. Everytime a cell divides, its telomeres shorten more and more. Until there is a time when cell division is no longer possible.

There are enzymes, called telomerase, that may increase the telomeres indefinitely, rendering cells effectively imortal.

Just make those women (and men) produce telomerase in every single cell of their body except on the ovocytes. Rather, when the woman arrives at your Heaven/Hell, shorten the ovocyte's telomeres so as to not the able to undergo one single cell division.

Upon fertilization, the short telomere won't let the ovocyte complete meiosis. You will now have 1,5x the amount of chromosomes that a human being has. People with Down syndrome have just 1 more chromosome. Imagine having 23 more chromosomes! It's incompatible with life! There would be no reproduction whatsoever... but there would be menstrual cycles.

From the mention of an afterlife and "last save state" reset, I'm taking this in the context of science fantasy - there are some based-in-fact elements, but on the whole, we're talking about a fantasy setting.

So in that context, you can look to other examples of immortal beings, either of the biological-reproduction variety (Tolkienesque elves, D&D-style dragons) or of the spiritual-reproduction variety (Buddhism-inspired reincarnation, some fictionalized treatments of early Christian/Old Testament angels).

In the spiritual case, your beings are really only as human as they believe themselves to be. Any biology they exhibit is purely a matter of habit and self-image, and who actively imagines themselves digesting (for example)?

## One explanation for limited reproduction in this case, is a "zero-sum" situation - any newly-born beings would require that some other being be reborn/reincarnated. Perhaps this is such a great (and noble?) sacrifice that it is just not done with any frequency.

In the biological case, your "100% human" entities are some new humanoid type, somehow freed from whichever of the maladies of the human condition you desire. You've already freed them from death, so what about injury, illness, hunger, etc. Just as @Separatrix above mentions, you can free your females from menstruation just as easily. (You could also free your beings from biological gender - for some folks, that is true Paradise.)

I would also point out that not all real-world mammals have a "monthly" fertility cycle - most are annual/semi-annual, and many are only fertile if other basic living conditions are met (sufficient food, clean-enough air/water/soil). These immortals could simply have an extremely long-wavelength cycle, with eons between fertility periods, assuming technology or magic does not intervene.

Rather than making these immortal women completely infertile, a good balance might be a single cycle window where in a woman could become pregnant with a child within the first month of entering this new realm because this will be her last menstration. The explaination being her body adapts to the new environs and shuts down mensing because it is unnecessary.

Another idea to play with would be the women arrive already with child. It might be that this is the way all women arrive, they have one child, then become infertile and without menses, or just the women who were are already pregnant before they transitioned into this world.

Either of these directions would create interesting character and social implications for the world you are building. For example, if you decide to go with women who arrive already pregnant, perhaps these women are celebrated by the society for their special role as mothers? Perhaps becoming a mother is hard because the child immediately returns to the realm the mother just came from? Just some thoughts.

-C

I would say you would want some children anyway as a practical social matter. Imagine if you only had the same 1000 people to talk to, you would soon know everything about everyone. They intern would know about you, and everyone would be bored. No new ideas would emerge, and your place would end up being a boring nightmare.

Well, periods are for removing unused eggs. If they can't make children, why would there be eggs? So there would be no eggs to remove. Thus, no periods.

• False. If the oviduct is jammed, eggs cannot propagate to the womb and the woman is sterile. Yet, the cycle still goes on and other "systems" and "procedures" are working as usual. – Crowley Nov 23 '16 at 13:00
• @Crowley Alright, but assuming no biological malfunction, which would probably be the case for an immortal, if they can't get children, there can't be eggs. – stommestack Nov 23 '16 at 13:04

I agree with FirstLastName, it would be easier to tackle this issue by changing the idea of them not being affected by time to the idea that time resets itself on a biological scale for them, i.e they go through a 24-hr cycle of time biologically at the end of which they reset to back to how they were at 0 hrs, which would give you the freedom to decide if they were menstruating during their time of original death they would continue to in the afterlife, however statistically most would not be, this would also help with the idea of pregnancy as after 24hrs the fetus would cease to exist.

Maybe we should think less about why a world would need a menstrual cycle and more about why male and female, exist.

A menstrual cycle would imply the creation of eggs to be complimented by sperm. If no such cycle exists, then there isn't a need to propagate genetic code.

This phenomena forces your hand to acknowledge the chief motivations of biology. In a stochastic system, subsidiary systems (menstrual cycles, the philosophical implications of the golgi bodies, the necessity of flagellation, etc) are used as relays to provide coverage for the overall economy of survival.

So, no.

But then you would need to tailor their relays to an end goal that presupposes a biological crescendo; that all systems participate in the infinite survival mechanisms to hedge against all threats to survival.

It's in this moment that we can define the immortal being's phenomena as a static compendium of non-trivially, proficient resilience—an infinitude to match such a continuous identity

Well I think if a woman is about to be immortal you can make them either be born without eggs but having normal levels of estrogen or create your immortal girl with Androgen insensitivity Syndrome. Both options will make them never menstruate and be esterile. If they are immortal making them infertile pose no risk in having a superpopulation of immortal people.

## protected by Community♦Nov 23 '16 at 20:36

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