What is the most common cause of "self correcting" infertility?

I know that’s not the correct term, but this:

A couple try to have a baby (or at least don’t try not to) for some period of time- several years even- and have no success (neither full-term pregnancies nor miscarriages or stillbirths).

After several years however the woman conceives and has a full-term healthy child, and after that first child the children come as regularly paced as the couple desires.

This happened with my parents (married 7.5 years before my sister was born- she could not get pregnant- then had 3 [and in case you’re wondering we look like our father;)]) and with my aunt, and you find it a good bit in genealogy*. I’m just curious what will cause infertility but correct itself without medical intervention after a few years. (My parents and my aunt/uncle went to fertility specialists in the 1950s but obviously there’s been some work since then.)
*Admittedly in genealogy there’s no way of knowing if there were miscarriages since they weren’t usually recorded, though stillbirths and infant deaths usually were. The real Charles and Caroline Ingalls {of Little House fame} were married 5years before their oldest was born and in records she’s listed as having given birth to 5 children (her 4 daughters and the son who died in infancy) with no evidence of any conceptions in that 5 years. Jefferson Davis’s wife Varina did note her trouble conceiving during the first years of their marriage, but after 4 years of no kids [actually 6 but he was away from her for 2 in D.C. and then Mexico] she gave birth to 6 in the usual succession [about 1 every couple of years], so another case.

I think it was Stephen Potter who pointed out that doctors are the only profession who can actually increase their professional standing by saying “alas, we don’t know” in a sufficiently solemn way.

A high proportion of infertility cases have no identified cause. I assume that this is true also of the cases which resolve spontaneously.

Apparently the symptoms of PCOS (which can cause infertility) can be milder following a successful pregnancy.

I can’t find a good online cite for this, but a book I own called The Short Life & Long Times of Mrs Beeton claims syphilis as a likely reason for Isabella Beeton’s early run (7 years) of stillbirths and sickly short-lived infants, and that she was probably recovering at about the 7-year mark (at which point she had two healthy children, dying in childbirth with the second)

I don’t think (untreated) syphilis is very common today, but it certainly was a hundred years or so ago

It could also be down to changes in diet or lifestyle (job etc). About a third of cases of infertility are male factor, and it could be that for the initial period of time, the male partner is ingesting, or being exposed to, something that decreases the count/motility/morphology of the sperm. If this then changes, and the sperm quality improves, the couple might then ‘suddenly’ go on to have normally spaced children.

Or how about a scenario where, again, lifestyle factors (working away from home, working long hours) mean that for an initial period of time the couple isn’t having intercourse enough at the right times. Things change, and suddenly they have the time and energy to get busy when it matters (even if they don’t know this).

Also, in the cases of unexplained infertility, doctors are usually unable to give a diagnosis (sometimes they can after you have been through advanced fertiltity treament like IVF). However they will always say that there is a possibility that you may conceive naturally, even if you haven’t for the preceding, say, 5 years. It could be that the couple was unlucky, for wont of a better word, for a long time, and then hit the jackpot several times in a row. Not a great answer, but as those of us who have been through infertility and fertility treatment know, there aren’t often a great many satisfactory answers to the questions we have as to why we can’t conceive or when we might conceive.

I’m going through unexplained infertility right now (further investigation pending, but everything is normal - cycle, Day 3 and 21 blood tests, I ovulate, track my temps, blah, blah, but next step is a laparoscopy) and a lot of couples are in the same boat - a surprising number, to be honest. Some get pregnant with little or no intervention, some need medical help.

It could be a combination of things. The woman could have cervical stonosis (a very tight cervix) and the man could have the bare minimum of normal sperm, or a normal count with abnormalities in each sperm.

Changes in lifestyle or diet can make a couple more fertile. Being overweight can cause problems, as can having a poor diet, smoking, or not exercising. If a woman loses 50 lbs., that may be the ticket to get knocked up.

There are some vitamins and herbs that some say can help (though the Dope doesn’t like alternative medicine!), some people just need help with cervical mucus (like me, I don’t produce much, so we use PreSeed). It could be timing - does she know when she’s fertile and do they do any type of intercourse pattern?

If all tests come back normal (i.e.: HSG, laparoscopy, semen analysis, clomid challenge, blood tests, etc.) then it’s usually unexplained fertility, but that doesn’t mean they can’t still have a child.

Did your dad switch from briefs to boxers?

All the other stuff that isn’t a serious medical condition - diet, obesity, etc seem to be covered.

But there are a lot of things that can make a man more or less fertile.

Other obvious question:
Were they doing it right?

Conversely, if a woman is extremely fit - daily workouts at the gym, triathlete, etc - the doctor may ask her to take it easy and gain a few pounds. The reproductive system needs resources available to help it work right.

Yeah, Sampiro, did your parents do too much anal and not enough of the old fashioned way?

Don’t know if it’s relevant, but I know from experience that it’s common in horses to have a broodmare produce a foal every year, regular as clockwork, even when up in years (up to age 20, 25, or beyond). But if for any reason, the mare misses a year, and does not produce a foal, it is often very difficult to get her back in foal the next year.

An aged broodmare’s reproductive system seems to continue just fine as it’s going, but if it ever stops for a year, it can be real hard to restart.

Yep. As a woman afflicted with Polycystic Ovarian Syndrome, that’s something they told me. My doc told me that once I have a kid, the symptoms won’t be as severe, usually. Your body starts producing different hormones in pregnancy and kind of slightly “re-boots” your ovaries.

Some of it could be statistical variance. About 85% of women who have regular intercourse will become pregnant over the course of a year. Ergo, 15% will not.

A certain percentage of women will just not get lucky over several years. Then the dice come up double sixes.

The Lovely and Talented Mrs. Shodan and I went thru a little of this - all kinds of poking and prodding and exams, and at the end, “We can’t find anything wrong with either of you”. We went ahead with adoption (and I have a vasectomy) so we never found out if we would have had children the old-fashioned way.

Regards,
Shodan

That’s a pretty definitive factoid. I know a lot of women with regular sex lives who don’t get pregnant every year. Citation of this number please.

I thought of another scenario, although this one would only apply to more recent times. If a couple fails to conceive for a period of time, and then goes on to have fertility treatment, they could then decide that when they wanted another kid, they were just going to go straight back to treatment, rather than trying for another 3 or 4 years on the offchance. To the outside observer, not knowing of their treatment, it could look like a long time with no kids and then all of a sudden a few in a row. Many couples who go through IVF will have left over frozen embryos, and it would make sense to go back and try them when they were ready.

Personally speaking, I have no intention of waiting another 3 years after this kid is born before going back for more IVF. If it doesn’t happen naturally within whatever time period seems right, I’ll be making that appointment (which could well be three years, but you see my point!)

Apologies for answering for Shodan, but I believe he meant couples not using any form of contraception.

It’s a pretty widely used statistic, so I’m sure there’s a more authorative cite out there, but here’s something for starters.

( Bolding mine)
Well, there you have it. I’m surprised no one thought to check that.

That’s a chart of people trying to conceive - not of every woman who is active sexually.

A)I’d buy 85% success rate per year of people trying to concieve.

B)I don’t really believe that 85% of women who are sexually active and don’t use contraception get pregnant in a given year. I’m sure the statistic is a high, but not as high as just those people trying to conceive.

C) I definitely have problems with saying 85% of sexually active women get pregnant each year.

The difference between A and C is absolutely huge.

Sorry, maybe I wasn’t clear enough. I meant couples not using contraception, trying to conceive, which I believe is what Shodan was talking about (seeing as we are talking about infertility here).

Even then, many couples trying to conceive don’t do a particularly scientific job of it (intercourse in the most fertile window), so I would assume that that statistic isn’t too far off a regular couple just having lots of unprotected sex over the course of a year.

Cite.

Regards,
Shodan

An average couple who is regularly having unprotected intercourse is trying to conceive whether they realize it or not.

Regards,
Shodan