When to See a Fertility Doctor: Timelines by Age

If you are reading this, you are probably either about to start trying or a few months in, and the question quietly forming in your head is some version of "how long is too long to wait." This post answers that question with an age-by-age rule, a clear list of situations that override the wait, and what the first workup actually looks like so you can walk in knowing what to expect.

The standard advice you have probably heard is "try for a year and then see someone." That advice is correct for some couples and badly wrong for others. The first thing I want to settle is the age threshold, because the guidelines themselves shift it, and most of the harm I see in clinic comes from people taking the under-35 advice when they are 37, or assuming nothing can be done when they are 41.

The standard rule, and why it has an age bracket

The clinical definition of infertility used by the National Institute for Health and Care Excellence (NICE) in the UK and the American Society for Reproductive Medicine (ASRM) in the US is the same in shape. Under 35, infertility is twelve months of regular unprotected intercourse without conception. At 35 and over, that threshold halves to six months.^{1 2} ASRM has further clarified that for people 40 and over, immediate evaluation is appropriate; you do not need to "try" for a defined period first.

The reason the threshold halves at 35 is biological, not moral. Monthly fecundability, which is the chance of conceiving in a single cycle, declines gradually through the late twenties and early thirties and then steepens. The variability of female reproductive ageing is well described: the ovarian reserve and the rate of follicular atresia accelerate from the mid-thirties onward, and the curves are not linear.³ Six months at 36 is meaningfully different from six months at 26 in terms of what is happening biologically inside the ovary.

I want to be clear about what meeting the threshold means. It does not mean something is wrong with you. It means you have crossed the line where a baseline workup is reasonable and where the clinical community has agreed that further waiting is no longer the best advice. Many couples who hit twelve months at 32 conceive in month thirteen with no intervention. The point of the threshold is to stop time from quietly draining out without anyone looking at why.

Age-by-age timelines

The age you are reading this at is the single most useful variable for deciding when to see someone. Below is how I actually break it down with patients in clinic.

Under 35

Try for twelve months before requesting a workup, unless one of the red flags later in this post applies. Monthly fecundability in healthy young couples is around 20 to 25%, and cumulative pregnancy rates reach roughly 80 to 85% by twelve months of trying.⁴ If you are 28, have regular cycles, and have been trying for four months, the most useful thing I can tell you is that you are well within the normal range and that anxious testing this early will not change anything.

The exception, even under 35, is when something about your history is already abnormal. Long cycles, absent cycles, known PCOS, endometriosis, prior pelvic surgery, severe period pain, or a partner with known testicular history all change the picture. We will get to that list in the next section.

35 to 37

Try for six months before workup. This is the bracket where I have lost count of how many couples sat in front of me at 36 saying "our GP told us to give it another year," and that year was the wrong year to spend. Fecundability drops modestly in this window, and ovarian reserve begins its more rapid decline. The clinical guidelines explicitly shorten the timeline here for a reason.^{1 2}

If you are 35 to 37 and approaching the six-month mark, book the GP appointment now rather than at month six. A baseline workup takes weeks to complete, and you want the results in hand by the time the six-month threshold is crossed, not just starting the queue.

38 to 40

See a doctor at three to six months of trying, or before starting if you have any risk factors at all. Fecundability in this bracket is roughly 10 to 15% per cycle, and the cumulative pregnancy rate by twelve months drops more sharply than many patients expect. I would much rather you walk in with a baseline anti-Müllerian hormone (AMH) and antral follicle count (AFC) before you start, so the conversation about treatment options is informed rather than reactive.

AMH at this stage is best framed as a counselling number, not a prediction. A low AMH at 39 does not mean you cannot conceive naturally. It does mean that if you decide to escalate to IVF, your stimulation protocol will be designed differently, and the timeline conversation needs to start sooner.⁶

40 to 42

See a doctor before starting, or at three months at the latest. At this age, time-to-treatment matters more than time-to-diagnosis. Twelve months of trying followed by a six-month workup followed by a nine-month referral wait is twenty-seven months, and at 41 that is a different decision than at 31.

I will have the realistic conversation with you about success rates with your own eggs versus donor eggs at this stage. I do not catastrophise, and I do not over-promise. The published data on autologous IVF outcomes by age is sobering past 42 but not zero, and the right path is whatever lets you make a decision with full information rather than panic.⁷

42 and over

See a fertility specialist before starting trying. The decisions around IVF, donor egg, the realistic goal, and the financial and emotional commitment of treatment all need to be on the table from the first conversation. Waiting six months to see if natural conception will work at 43 is, in most cases, six months that would have been better spent on a stimulation cycle or on the donor egg conversation. I say this gently, not to alarm. I say it because the couples I see who regret their timeline at this age almost always say "I wish we had started sooner."

Reasons to skip the wait, at any age

Several specific situations override the age-based rule. If any of these apply to you, you do not need to wait twelve months, or six, or three. You should book an appointment now regardless of how long you have been trying.

• Irregular cycles: cycle lengths consistently shorter than 21 days or longer than 35 days, or cycle-to-cycle variability of more than seven days. This is the single most common reason couples should not be waiting the year.
• Absent periods for three or more months (secondary amenorrhoea), outside of breastfeeding, pregnancy, or hormonal contraception.
• Known PCOS, endometriosis, fibroids, pelvic inflammatory disease, or prior pelvic or tubal surgery.
• Previous chemotherapy, pelvic radiotherapy, or ovarian surgery on either partner.
• Two or more miscarriages, which is a separate diagnostic pathway that should not wait for a "trying for a year" threshold.
• Partner with known testicular trauma, varicocele, mumps orchitis after puberty, prior chemotherapy, or cryptorchidism (undescended testes in childhood).
• Same-sex couples or single parents planning with donor sperm, who are on a different pathway from day one and should be in front of a GP or REI before treatment cycles begin.

A more detailed walk-through of these red flags lives in our companion post on the signs you might need fertility help sooner. The short version is that if any of these apply, the year-of-trying rule is not your rule.

GP first, or fertility specialist first

The route into the workup depends on where you are and how your healthcare is structured.

In the UK, the GP is the standard first stop in the NHS pathway. The GP can order most of the baseline tests directly and then refer to a fertility clinic when criteria are met. The Integrated Care Board (ICB) controls funded onward treatment, and the criteria vary by postcode, which is worth knowing early.

In the US, the route depends on insurance. Many couples go directly to their OB-GYN, who orders the initial workup. Others go straight to a reproductive endocrinologist (REI), particularly if their plan allows it or if they are paying privately. Either route is reasonable.

Wherever you are, the baseline workup is broadly the same: day 2 to 5 follicle stimulating hormone (FSH), luteinising hormone (LH), and oestradiol; AMH on any cycle day; thyroid stimulating hormone (TSH) and prolactin; mid-luteal progesterone to confirm ovulation; transvaginal ultrasound for antral follicle count and uterine cavity; and a semen analysis for the partner.⁵ Our post on talking to your GP about fertility walks through how to ask for this baseline without losing your ten-minute appointment to a "just keep trying" script.

What a first fertility workup actually looks like

If you have never had one of these, here is what is on the order form. This is general; your clinician may add or remove tests based on your specific history.

For the person carrying

• Day 2 to 3 hormonal panel: FSH, LH, and oestradiol. These give an early-follicular signal about ovarian reserve and pituitary signalling. Timed bloods only; not useful on day 14.
• AMH on any cycle day: AMH is a snapshot of ovarian reserve. It is not a fertility forecast and a low number does not mean you cannot conceive. A low number does change how a stimulation protocol would be designed if you went on to IVF.
• TSH and prolactin: Untreated thyroid disease and hyperprolactinaemia are common, treatable, and easy to miss. Both can suppress ovulation.
• Screen for diabetes if BMI or history suggests it (HbA1c, fasting glucose).
• Transvaginal ultrasound: antral follicle count, uterine cavity, fibroids or polyps, ovarian cysts.
• Mid-luteal progesterone: a single blood test seven days after suspected ovulation, used to confirm that ovulation actually happened in the cycle being measured.
• Tubal patency: hysterosalpingogram (HSG) or hysterosalpingo-contrast sonography (HyCoSy), usually after the above results are in.

For the partner

• Semen analysis to WHO 6th edition criteria.⁷ Two to seven days of abstinence before the sample, analysed at a recognised lab.
• Repeat after six to twelve weeks if the first result is abnormal: a single abnormal sample is not a diagnosis. Spermatogenesis is a roughly seventy-four-day process, and one fever or one bad week can throw a single result. Repeat before any conclusion.
• Hormonal workup (FSH, LH, testosterone) only if the semen analysis is genuinely abnormal on repeat testing.

If I could change one thing about how the average couple's workup gets ordered, it would be this. Semen analysis should be in the first round of tests, not the third. It is a single sample, a single lab, a single week. Roughly half of subfertility involves a male factor in part or in whole, and the test is cheap and fast. We should not be doing nine months of investigation on one body when the other has not been checked.

What "abnormal" results actually mean, and what they do not

The hardest part of receiving fertility test results is the gap between the number on the page and what it means for you. Three things are worth holding onto.

First, AMH below the age-adjusted reference range does not mean you cannot get pregnant. It means you have fewer eggs remaining than the population average for your age. The eggs you do have are not, on average, worse quality. AMH predicts response to IVF stimulation; it does not predict natural conception well.

Second, a single low semen analysis is repeated, not acted on. I have seen couples in genuine distress over a one-off result that, on repeat six weeks later, was completely normal. Repeat the test.

Third, "unexplained infertility" is a real and common diagnosis, and it is not a failure of testing. It means the standard battery of investigations did not find a single clear cause. It does not mean you cannot conceive. It changes the treatment conversation, but it is not a verdict.

Calm framing on results matters more than completeness. Your job, walking out of an appointment, is to know what the result is, what it means in the context of your other results, and what the next step is. Not to leave with a number you do not understand and three weeks of Google in front of you.

When to escalate within the workup

The other place couples lose time is after the workup, not before it. A few markers I use in clinic for when to push for an REI referral if you are still under a GP or general OB-GYN.

• Three months after an abnormal result without a clear plan: ask for a reproductive endocrinology referral. Abnormal results sitting in a notes folder are not investigation; they are deferral.
• Tubal blockage, severe male factor (total motile sperm count under five million), or age 38 and over: fast-track to the IUI or IVF conversation. Endless monitoring at this stage is rarely the right answer.
• Two or more miscarriages: separate recurrent pregnancy loss pathway, often a different team.

A bridge to the next stage of the journey is our pillar on getting diagnosed, which covers what the conversations and tests look like once you cross from "trying" into "investigating."

What to do this week

If you have read this far, the most useful thing you can do is convert the reading into a single action this week.

1. Note the date of your last day-1 period. If you cannot remember the exact date, estimate.
2. Map your last three cycle lengths, or estimate them if you have not been tracking. Pattern matters more than the exact numbers.
3. Write down your age, BMI if you know it, any known conditions, current medications, and your partner's relevant medical history including any childhood testicular surgery or cancer treatment.
4. Book the GP or OB-GYN appointment with one specific ask: "I want to start trying," or "I have been trying for X months and I would like a baseline fertility workup." Specific is what short appointments need.

If you are not yet at the threshold but planning, the preconception checklist is a good companion piece. If you are at the threshold, the next post in this section walks through the GP conversation itself.

What's next

• If you are not yet at the threshold but planning ahead: Preconception Checklist
• If you meet the threshold and are ready for the appointment: Talking to Your GP About Fertility
• If you have red flags, PCOS, or a feeling that something is off: Signs You Might Need Fertility Help Sooner
• If results come back abnormal and you have been told something needs further investigation: Getting Diagnosed (Section 2)

Sources

1. National Institute for Health and Care Excellence. Fertility problems: assessment and treatment. NICE Clinical Guideline CG156. 2013, updated 2017. https://www.nice.org.uk/guidance/cg156
2. Practice Committee of the American Society for Reproductive Medicine. Definitions of infertility and recurrent pregnancy loss: a committee opinion. Fertility and Sterility 2020;113(3):533-535. https://www.asrm.org/practice-guidance/practice-committee-documents/definitions-of-infertility/
3. te Velde ER, Pearson PL. The variability of female reproductive ageing. Human Reproduction Update 2002;8(2):141-154. https://academic.oup.com/humupd/article/8/2/141/660766
4. Practice Committee of the American Society for Reproductive Medicine. Optimizing natural fertility: a committee opinion. Fertility and Sterility 2017;107(1):52-58. https://www.asrm.org/practice-guidance/practice-committee-documents/optimizing-natural-fertility-a-committee-opinion-2022/
5. American College of Obstetricians and Gynecologists. Committee Opinion No. 781: Infertility workup for the women's health specialist. Obstetrics & Gynecology 2019;133(6):e377-e384. https://www.acog.org/clinical/clinical-guidance/committee-opinion/articles/2019/06/infertility-workup-for-the-womens-health-specialist
6. ESHRE Guideline Group on Female Fertility Preservation. ESHRE guideline: female fertility preservation. Human Reproduction Open 2020;2020(4):hoaa052. https://academic.oup.com/hropen/article/2020/4/hoaa052/5912280
7. World Health Organization. WHO Laboratory Manual for the Examination and Processing of Human Semen, 6th edition. Geneva: WHO; 2021. https://www.who.int/publications/i/item/9789240030787