TTC With Endometriosis and Short Cycles Over 35
Should you keep waiting or get evaluated now with endometriosis, short cycles, and age 35+?
Get evaluated now — ASRM guidance says cycle length under 25 days and known endometriosis are each, independently, conditions that warrant testing without the standard 6-12 month wait. Combined with a year already spent trying, there isn't a strong evidence-based case for continuing to wait and see.
If you have a known endometriosis diagnosis, you're in your mid-to-late 30s, your cycles run on the shorter side, and you've been trying to conceive for about a year with negative test after negative test, you're carrying a lot of uncertainty about whether to keep waiting or get evaluated now. The research on this is actually more direct and more actionable than most people realize — short cycles, endometriosis, and time already spent trying all point toward the same conclusion, independently of each other.
First, Let's Retire "Just Relax and It Will Happen"
This advice is not just unhelpful — it's not supported by the evidence, and it's worth knowing that clearly rather than just feeling annoyed by it. A landmark meta-analysis published in the BMJ, led by researchers at Cardiff University, reviewed data from 14 studies involving 3,583 women undergoing fertility treatment and found no association between pre-treatment emotional distress and treatment outcomes — women experiencing significant stress were just as likely to conceive as those who weren't. A 2016 Cochrane review of randomized controlled trials on stress-reduction interventions and pregnancy rates found the evidence too inconsistent and low-quality to draw a meaningful conclusion in either direction. The honest scientific position: infertility causes real, measurable stress, but there's no rigorous evidence that stress causes infertility, and relaxation is no more a cure for a physiological fertility issue than it would be for any other medical condition. If you're hearing this advice, it's fair to redirect the conversation toward what's actually happening with your cycle and diagnosis. If that is your situation, this is where we start: PCOS & Endometriosis.
What Short Cycles (less than 25 Days) Actually Indicate
This is worth taking seriously rather than dismissing as normal variation. A systematic review and meta-analysis found that menstrual cycle length is closely tied to ovarian reserve markers throughout the reproductive years, and that a short cycle length compared to a longer one within the "normal" range (21-35 days) is significantly associated with lower ovarian reserve test values, reduced fecundability, and worse IVF outcomes — independent of age. A separate cohort study found that clinical pregnancy rates were significantly lower in women with cycles of 21-28 days compared to those with cycles of 29-35 days, and that shorter menstrual cycle length correlated with lower AMH and reduced antral follicle count.
The mechanism behind this involves the follicular phase specifically — the portion of the cycle before ovulation. Research from the BioCycle Study, which tracked hormone levels across cycles in 259 healthy women, found that shorter cycles come with an earlier rise in FSH, meaning the body is essentially recruiting and selecting a dominant follicle sooner than it otherwise would. This pattern — a compressed runway to ovulation — is the same one seen as ovarian reserve naturally declines with age, whether due to age itself or diminished ovarian reserve independent of age. Regular ovulation is a good sign in general, but a consistently short cycle length, even a regular one, isn't the same thing as a fully reassuring fertility picture — it can be an early, easily overlooked signal worth investigating directly.
The Endometriosis Piece
Endometriosis has a real, measurable effect on monthly conception probability. The typical monthly fecundity rate (chance of conceiving in a given cycle) for couples without fertility issues runs 15-20%; for women with untreated endometriosis, that rate drops to an estimated 2-10% per cycle. The exact mechanism isn't fully settled, but proposed pathways include pelvic adhesions and distorted anatomy, chronic pelvic inflammation affecting the reproductive environment, and immune dysregulation — all of which can interfere with conception independent of whether ovulation itself is happening normally. Related reading: severe endometriosis without pain.
What This Means for the "Wait or Get Evaluated" Question
This is where the evidence gives a genuinely clear answer, not just a general reassurance to "talk to your doctor eventually." ASRM's committee opinion on fertility evaluation is explicit: while general guidance suggests waiting 12 months (under 35) or 6 months (35 and older) before evaluation in the absence of other risk factors, diagnostic testing should be initiated without delay for anyone presenting with a condition already known to affect fertility — and menstrual cycle length under 25 days is specifically named as one of those conditions, alongside known or suspected endometriosis.
In other words: a cycle length under 25 days and a known endometriosis diagnosis are each, independently, reasons ASRM guidance says shouldn't wait for the standard timeline - they warrant evaluation now. Combined with already being a year into trying at 36, there isn't a strong case for continuing to wait and see. This is a situation where "go get evaluated" is the evidence-supported answer, not an overly cautious one.
What a Reasonable Next Workup Looks Like
Given this specific combination — known endometriosis, short cycles, a year of trying — a reasonable initial evaluation typically includes AMH and antral follicle count (to directly assess ovarian reserve given both endometriosis and short cycle length independently raise this question), mid-luteal phase progesterone testing (to confirm adequate progesterone production and rule out a luteal phase issue), updated pelvic imaging to check for any endometriomas or anatomical changes since the original diagnosis, an HSG to assess whether the fallopian tubes are open (relevant given endometriosis's association with pelvic adhesions), and a semen analysis for a male partner, since a full evaluation looks at both partners rather than assuming the explanation lies with one.
None of this needs to happen at once, and it's reasonable to start with a conversation with a GP or gynecologist — something many patients do first before reaching us in Huntington — about referral to a fertility specialist, given the specific risk factors already present. The point isn't to create alarm - it's that the evidence points toward "start the evaluation now" rather than "wait and see for a few more months," which is a meaningfully different, more actionable answer than the wait-and-see advice so often given by default. Related reading: failed FET with severe adenomyosis.
This article is for general educational purposes and isn't a substitute for individualized guidance from your own physician. Evaluation timing and testing decisions should be made directly with your care team.
East to West Fertility, is a metabolic and immune-focused fertility practice in Huntington, NY, serving Long Island, NYC, and beyond. We help patients with endometriosis and ovarian reserve concerns build a clear evaluation and treatment plan, working alongside your OB/GYN or REI care. Learn more about our Metabolic & Immune Fertility Evaluation at easttowestfertility.com or call 631-416-4940.
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