Somebody please give me a biology lesson

[JustPutSomeGlitterOnIt]

Ok so I have 3 children and have started on the injection to avoid having any more.
But I have a theory about being on the injection.
A terrible, troubling theory.

Here are my premises:

1. Menopause happens when I run out of eggs
2. I am fertile up until I run out of eggs
3. I run out of eggs by releasing most, and a few dying
4. I don't release eggs on the injection
5. Therefore I am just delaying my fertility, and I'm going to get to 50+ with all my little eggs nice and intact and be fertile up to like bloody eighty YEARS OLD!

Please somebody explain to me why I am wrong.

I'm 26 now, so I've got another entire LIFETIME in which to avoid a surprise.

Surely if I'm not releasing eggs, they're just sitting there until I come off the injection. And all of those years when normally you're releasing one a month and usually bleeding it out aren't going to happen. So my eggs will last far longer than if I were not on the injection. And menopause won't hit until I get rid of them all, which will only start to happen again once I come off the injection, which isn't going to be for DECADES.

No?

TIA

Ooh I’m interested in this too. Good question OP!

Oh thank goodness someone doesn't think I'm being an absolute loon!

I just wonder if we're all growing into generation of enormously delayed fertility and menopause!

The only option I can think around it is that eggs die with time. But still, we need to release some too.
Menopause only happens around 50 because we all have a similar amount of eggs and a similar amount of periods and children.

Is ovulation inhibiting contraception going to change this?

This is why my science teachers avoided me

Good question! I am older than you (nearly 40) and would like to go onto hormone contraception but wonder how I will then know if my menopause starts??

I don't think it is because your eggs deteriorate over time too. I was on the pill most of my adult life (apart from pregnancies) and went through the menopause quite early at 47. I may be wrong though, it's a good question.

Logic would dictate you are correct, but there’s little evidence it’s true.

academic.oup.com/humrep/article/16/8/1657/624673
plannedparenthood.tumblr.com/post/73874467438/does-birth-control-delay-menopause

It’s a bit more complicated than that.
As you get older, it’s not just the eggs that are fewer or of less quality. Hormones such as progesterone and oestrogen vary a lot too. It’s the variation on hormones for example that starts the menopause, not the fact there are no eggs left.

Eg women with PCOS don’t ovulate (or not as often as they should) so often have a big egg reserve when they are 40yo (measured as a high AMH). It doesn’t mean that they can get pregnant easily or that they never go through the menopause because the other hormones behave ‘normally’ and decline with age so the menopause still starts.

Does it make sense??

Oh ok! Well that's reassuring.
Yes I can see that they'd also die and deteriorate, but surely no quicker than if you're not on contraception - so you'll still be holding on to more than usual.

My understanding is that you start life with 1-2 million of eggs already in your ovaries and they gradually die off - down to around 72,000 by the age of 30. So they'll still be dying off whether you are on contraception or not.

Surely ovulating inhibiting contraception only mimics what would have happened in the past though, where women spent much of their adult years pregnant or breast feeding and therefore not ovulating? So my GGM had 15 children, pretty much one every year or so from her mid 20s. They still entered menopause in their 50s.

There has to be more to it than just the number of eggs eg the age of the eggs and the production of female hormones.

Interesting question though.

Aaaahhh thank you Hermione yes. So essentially start of menopause isn't actually determined purely by a lack of eggs - it's a change in hormones levels too?
I thought that was the egg rather than the chicken - I.e hormone changes were prompted by a lack of eggs

Aahh yes that's true Arthuritis if you're 'not releasing' them from contraception, you're quite likely to be 'not releasing' them from 9 months of pregnancy or breastfeeding instead!
So maybe it balances! Ish

It's declining hormone levels that equates to menopause not number of eggs left.
If it was egg numbers why would some people have an early menopause?

Well jelleybean I'd just assumed that they'd been born with far fewer than average eggs

I have just started the injection. I’m in my 40s. I asked about how it would effect the menopause and she said it would just happen as normal.

The menstrual cycle is controlled by a cycle of hormones which each stimulate each other and cause things to happen, e.g. Follicle Stimulating Hormone causes the egg to mature in the ovary and causes oestrogen to be released from the ovary, which in turn causes the uterus lining to develop and another hormone to be released which causes ovulation.

Menopause happens when these hormones are no longer being produced. It has nothing to do with the number of eggs you have left.

Hormonal contraceptives like the pill or the injection artificially keep progesterone levels high which mimics pregnancy, so stops ovulation as the hormones which cause an egg to be released won't be released during pregnancy. So it's like your body thinks it's pregnant.

You definitely don't release most of them! On average 12 a year will be released, I think they die at a rate of around 1,000 a month or something like that.

Thank you celial. So it sounds like hormone change causes lack of eggs, not lack of eggs causes hormone change.

I was told as well when I made twins that they tend to be common in older mums whose hormones cause them to, as my boyfriend put it, 'carpet bomb eggs'. So basically, you get rid of a few each time nearing menopause

Bear Crikey 😳

What they don't tell you is that the injection isn't a contraceptive solution to last the rest of your reproductive life. I was on it for 5 years (the hormones contributed to a massive weight gain over that time) and then when I tried to book my next appointment they said actually it's not recommended long term as it increases risks of complications to have the injections for years it's a better solution for if you aren't ready to start a family yet or as a simple solution for the months in between having dc1 and ttc dc2. I would advise a different solution sooner rather than later.

But in answer to your question hormonal contraceptives work by tricking the body into thinking it is already pregnant. If menopause was just a case of running out if eggs, a woman could theoretically have back-to-back pregnancies into her eighties by only releasing one every 9 months. That obviously doesn't happen so it must be about more than just eggs.

Omg I actually wondered about this the other day. Good to know. Thanks people!

Such an informative thread.
So in theory if someones hormone levels were hightened after years of having injection, even though they're meant to be in menopause they could get pregnant?

The injection is only progesterone, it doesn't cause heightened levels, it basically gives you a steady level.
During a cycle progesterone peaks and then drops. The drop triggers the shedding of the womb.
If you have a fertilised egg implant the early embryo produces progesterone to stop the shedding, after a short time it produces bhcg the pregnancy hormone which takes over the job of progesterone.
So the injection, like the implant and mirena coil all release a steady state of progesterone, chence fooling your body into thinking its pregnant. So you don't ripen and release eggs.
There is no evidence to support claims the injection causes weight gain, or it increases risk of 'complications'. It is not recommended under 18 as starting it that early can increase risk of osteoporosis.
Other wise it is a safe and sensible method of contraception.

Yes that’s how women in their 60s can get pregnant.
They dont use their own eggs (the quality and quantity wouod t be good enough) and they inject hormones that replicate the real cycle before the implemtation of the embryo.
Once the embryo is implanted, it triggers another set of hormones to carry on with the pregnancy.