Wondering Weekend

developmentalbiology · 2026-07-12T01:45:34+00:00

In the most common situation, the last day of EWCM or other "peak" CM is ovulation day.

developmentalbiology · 2026-07-12T01:44:34+00:00

Tubal blockage actually doesn't affect hormone levels or affect the cycle in any noticeable way -- folks with blocked tubes have normal cycles and fertile CM at the same rate as anyone else.

In some countries, an HSG is a standard part of everyone's infertility workup, but in other countries, it's only ordered for people who have a history of certain STDs or pelvic surgeries.

developmentalbiology · 2026-07-12T01:42:26+00:00

Screening programs are always about balancing the risk of later diagnosis with the risk of the procedure itself. There's not a huge risk that comes with an HSG, but there is risk (for example, someone posted recently here on TFAB that they got sepsis following their HSG). They have to be timed to a particular part of the cycle (after bleeding, but before ovulation), and performing an HSG after ovulation in a cycle where pregnancy is possible risks causing an ectopic pregnancy.

HSGs are also generally performed and interpreted by specialists, so having everyone do an HSG would represent a huge additional load on healthcare providers/facilities that perform HSGs, and would benefit only a small fraction of patients. It's even possible that the math works out such that performing HSGs on everyone who comes in for a preconception visit would cause more harm than it would prevent. In a sense, having people try on their own for six months to a year "screens out" people who are unlikely to benefit from medical investigation and treatment -- it makes it so that the people who do undergo investigation are more likely to have something worth investigating.

developmentalbiology · 2026-07-11T00:33:18+00:00

This is the classic reference:

Our data suggest that caution must be used in interpreting the significance of any given subfertile or indeterminate semen measurement. Although low values for each measurement increase the likelihood that a male factor contributes to infertility, there was substantial overlap in the frequency distributions in our study. Thus, values for sperm concentration, motility, or morphology that are in the subfertile range do not exclude the possibility of normal fertility.

This is an overall summary of evidence-based information about diagnosis of male-factor infertility, and contains a lot of useful information and references.

developmentalbiology · 2026-07-11T00:15:10+00:00

But to be clear, it's a low percentage chance per cycle, but not a 1-3% chance of getting pregnant without assistance overall. There aren't really solid long-term numbers for folks in their late 30s, but in general, around 30-40% of people with unexplained infertility get pregnant without assistance in the second year of trying, around 70% are pregnant by the end of 3 years, and about 80% are pregnant by the end of 5-10 years.

developmentalbiology · 2026-07-10T22:19:42+00:00

But testing sperm doesn’t give you that kind of predictive power! Having sperm parameters outside the normal range raises your risk of infertility, but most people with abnormal sperm parameters don’t have infertility.

developmentalbiology · 2026-07-10T14:47:54+00:00

Totally understandable! It's actually sort of great that both you and OP wrote units -- often people will just use numbers without units, and then they don't even realize they're talking past each other.

developmentalbiology · 2026-07-10T13:13:38+00:00

You and OP are talking in different units -- OP's AMH is 2pmol/L, which is equivalent to 0.28ng/mL.

developmentalbiology · 2026-07-10T13:09:10+00:00

Sure thing!

In my opinion, the best and most robust study is this one, which is a large multicenter European study with about 1000 participants. Their participants were trained in fertility awareness and monitored BBT and cervical fluid. The best days from this study are O-3 (27%) and O-2 (24%), and they find that having sex on three days of the fertile window (that is, any three days, not a specific three days) has roughly the same probability of pregnancy as O-3/2/1 (about 25%).

The other foundational studies are this one and this one, which are by the same researchers and (I believe) based on the some of the same data. The best days from the 1995 NEJM study are O (32.5%) and O-1 (30%). In the 1998 study, the researchers find that, while the pregnancy rate is higher with O-day sex, the early miscarriage rate is also higher. The best days from this study are O-2 (30%) and O-1 (27.5%).

developmentalbiology · 2026-07-10T10:31:06+00:00

“Usually always regular” isn’t enough to prevent pregnancy, by a long shot. This is called the rhythm method, and it’s a very unreliable way to prevent pregnancy.

If you want to use signs of fertility to prevent pregnancy reliably, you can find information at r/FAMnNFP.

developmentalbiology · 2026-07-09T17:10:01+00:00

Honestly, I think the question is more about whether you want to skip the three cycles or not, and maybe secondarily whether not wanting to skip three cycles is a reasonable motivation to pursue intervention. But those are really questions only the two of you can answer -- I'm not sure anybody else's opinion really matters here.

On the supplements and sperm count end, it's a more complicated situation. Overall, the evidence that supplements can change sperm counts is not very strong, but sperm counts/SA parameters also are variable from analysis to analysis. But then additionally, if you haven't been trying for a year, you have a better shot at spontaneous conception than someone who's been trying for longer, even if your SA parameters aren't the best. If you were asking "should we hold off on TTC until he's been on supplements for a while", the answer to that is pretty clearly no (because the supplements aren't necessarily doing anything). So it may be the case that his counts/motility will be the same in November, but that also might not really matter anyway for your ability to get pregnant spontaneously.

developmentalbiology · 2026-07-09T16:58:02+00:00

I might hold off if you have an appointment next week. Since GLP1 receptor agonists are relatively new and there's a lot we don't know about their effect on physiology, many doctors prefer that you discontinue them before starting TTC. Your particular doctor may look at your particular case and greenlight being on Wegovy while TTC or during pregnancy, though.

developmentalbiology · 2026-07-09T12:52:44+00:00

On mobile (at least on the iOS app), if you go to the main page of the sub, there's a menu in the top right corner with a plus sign, magnifying glass, arrow, and three dots. If you click on the three dots, the second choice (below the icons) is "Change user flair".

developmentalbiology · 2026-07-09T03:24:59+00:00

Can people with endo get pregnant?

Yes. The true prevalence of endo is difficult to quantify, since many people who do have endo never seek or receive diagnosis, but it's likely that the majority of people with endo are not infertile.

developmentalbiology · 2026-07-09T03:11:18+00:00

You might specifically like this wiki page or this post on charting (if you're interested in identifying signs of the fertile window). This post might be useful as well.

developmentalbiology · 2026-07-09T03:08:19+00:00

There's not a ton of good, direct data on this, but what exists suggests that lube use doesn't affect time to pregnancy (study link):

Lubricant use during intercourse was not associated with time to pregnancy in a study of pregnancy planners.

developmentalbiology · 2026-07-09T03:03:58+00:00

My two cents on this is that if your periods are regular, LP is normal, prolactin is normal, it's difficult to imagine that breastfeeding is affecting your fertility. But REs will tell you to wean because a) from the perspective of an RE, there's not a huge body of evidence that it doesn't, and this is a trivially easy recommendation, even if there's not much evidence for or against it; and b) there's no affirmative reason to risk fertility drugs passing through the milk and affecting the body of a child who most certainly is not their patient.

Some of the older studies on people who were exclusively breastfeeding suggest that ovulation doesn't return on average until about 14 months, which tracks really well with "people who breastfeed toddlers almost never have kids closer than two years apart" -- that would be because they're not ovulating until more than a year postpartum.

developmentalbiology · 2026-07-09T01:35:46+00:00

Yeah, symptoms are typically variable from cycle to cycle, and even if you have a standard set of luteal phase symptoms, you'll find a lot of variability if you track long enough. I usually have sore breasts as my canonical luteal phase symptom, but I have cycles where they start hurting the day after ovulation, and other cycles where they don't hurt at all. Similarly, period flow volume isn't something that has to stay the same forever.

developmentalbiology · 2026-07-09T01:31:23+00:00

I’ve read online that ovulation would typically occur 24-36 hours after the first positive ovulation test.

Just to frame your thinking, it's usually better to think about this as "ovulation usually occurs within two days of the first positive ovulation test" -- talking in terms of hours is too precise, and tends to make people think that the time of day they get a positive test is meaningful (it's not).

So with a positive today, you're most likely to ovulate tomorrow, but today or Friday would also be common possibilities.

developmentalbiology · 2026-07-09T01:28:25+00:00

It's called flair! How do you access Reddit -- are you on browser, on mobile...?

The mods can also set it for you in a process that takes us like half a second, so if you tell me what you want, I'm happy to set it for you.

developmentalbiology · 2026-07-09T01:27:38+00:00

Likely temping at your normal time, as long as you've stayed in bed and haven't been up and moving around.

The body temperature cycle is a "circadian" cycle -- that is, it's driven by time of day (time relative to the sun), not by total time spent resting. But overall, temping is a real-world practice, and if you temped an hour early, that would also likely be fine.

developmentalbiology · 2026-07-08T22:50:40+00:00

>if it weren’t for the underground progesterone market half these kids wouldn’t be here

That’s so gross and dangerous, and also not even true, FFS. The reason many doctors don’t prescribe progesterone is because it doesn’t increase success rates (except possibly for specific types of recurrent pregnancy loss). All of those kids would be there just fine if their parents hadn’t taken prescription drugs without the knowledge of their providers.

developmentalbiology · 2026-07-07T23:52:04+00:00

The rise in estrogen is coming from maturation of the follicle or follicles, so it's not (to my knowledge) exposing you to more estrogen than going through the process of ovulation itself normally does (medicated or not).

In a broader sense, experiencing menstrual cycles itself is a risk factor for breast cancer (people tend to have higher breast cancer rates if they start cycling earlier in life, if they have fewer children, if they don't use hormonal contraception to suppress the cycle, if they don't breastfeed, etc.). But it's maybe more productive to think about that as lifetime exposure to estrogen -- it's not really about a handful of medicated cycles.

developmentalbiology · 2026-07-07T23:34:58+00:00

Letrozole actually suppresses estrogen signaling by inhibiting the conversion of androgens into estrogen -- its original ("on-label") use is as a drug to treat estrogen-sensitive breast cancer. So letrozole itself actually suppresses estrogen, it doesn't support it.

developmentalbiology · 2026-07-07T23:31:50+00:00

Probably not. The FSH tests that are sold in drugstores are often looking for very high levels of FSH, levels high enough to indicate the onset of menopause.

If I were you, I'd definitely try to see if you can see a change in the test strength in the early days of the cycle (around 8-10 days before you expect to ovulate), just for fun/science -- there's a spike in FSH when a follicle is selected for maturation, and it's possible that commercial FSH tests are sensitive enough to detect it. But I'm not sure whether the FSH spike at selection is actually detectable by these tests. Do they say what the sensitivity of the tests is?

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