The 2026 NICE Fertility Guidelines: When to Seek Help Conceiving

On March 31, 2026, the UK's National Institute for Health and Care Excellence (NICE) published NG257 - its first comprehensive overhaul of fertility guidance since 2013. It replaces the old CG156 guideline that a generation of clinicians had relied on.

The headline is a shift in philosophy: away from one-size-fits-all treatment pathways and toward individualised, diagnosis-driven care that starts in primary care, not the fertility clinic.

For anyone thinking about trying to conceive, the most useful parts aren't the funding tables. They're the clear answers to two questions almost everyone asks: How long should it take? and When should I actually get help?

This guide translates the new guidance into plain language - what changed, what it means for you, and what to do with the months before you need a clinic at all.

What "fertility problems" actually means

Doctors define infertility as not conceiving after a defined period of regular, unprotected sex - not as a permanent verdict. Most couples who haven't conceived in their first few months are completely normal.

The numbers behind that: among couples having regular unprotected sex, roughly 8 in 10 conceive within one year, and around half of the remaining couples conceive in the second year. So a few months without a positive test is expected, not a red flag.

What NG257 does is set out when the wait stops being routine and becomes a reason to investigate - and crucially, it makes that threshold depend on your age and your history, not a single fixed rule.

The problem this update solves

The old 2013 guideline was written for a different era. It treated most people heading toward IVF as broadly similar, gave little structured guidance to GPs, and barely acknowledged that conditions like endometriosis change the entire fertility picture.

In the years since, two things shifted. People are trying to conceive later, which makes age-related timing advice far more important. And the evidence on specific diagnoses - endometriosis, male-factor infertility, ovulatory disorders - got strong enough to justify tailored pathways instead of a single funnel toward assisted conception.

NG257 is the response: assess earlier, assess in primary care, and match the path to the diagnosis.

What changed

1. A clear "when to seek help" threshold

NICE sets the referral and investigation thresholds like this:

• Under 36: seek assessment after 12 months of regular unprotected sex without conceiving.
• 36 and over: don't wait the full year. You should be offered clinical assessment at presentation - that is, as soon as you raise it.
• Using artificial insemination: seek assessment after 6 cycles without conceiving.
• Any known cause or risk factor (irregular or absent periods, a history of pelvic infection, known endometriosis, previous cancer treatment, undescended testes in a male partner): get assessed earlier, not after the standard wait.

This roughly aligns with longstanding US advice from ACOG, which suggests evaluation after 12 months under 35 and after 6 months at 35 or older.

2. Fertility care starts in primary care

A major change is that the initial assessment now happens at the GP level, before any specialist referral. That includes baseline lifestyle guidance both partners can act on immediately:

• For women: alcohol, smoking, BMI, and folic acid before conception
• For men: smoking, recreational drugs, occupational heat exposure, and even underwear type

It also means earlier, simpler tests - confirming ovulation, checking for infection, and a semen analysis for the male partner - rather than a long wait to be seen.

3. Endometriosis recognised as a distinct fertility entity

For the first time, NG257 gives endometriosis its own pathway. Rather than treating it as background noise, the guideline calls for personalised assessment and a tailored plan - expectant management or surgery first where appropriate, then IUI or IVF if needed. If you've been diagnosed with endometriosis, this is the change most likely to affect your care.

4. Updated IVF and insemination access (NHS)

The funding tables apply to NHS-funded treatment in England specifically, but they signal how the evidence is read:

• Under 40: up to 3 full IVF cycles recommended
• 40 to 41: 1 cycle
• 42 and over: IVF is not recommended on cost-effectiveness grounds
• Intrauterine insemination (IUI): expanded to between 4 and 12 cycles depending on the indication

The guideline also explicitly includes trans and non-binary people and fertility preservation for the first time.

What this means for you

Strip away the institutional language and the practical message is simple:

If you're under 36 and otherwise healthy, give it a year of well-timed trying before you worry. Most people conceive in that window.

If you're 36 or older, don't sit on it. Both NICE and ACOG now agree that the calendar matters more than it used to, and waiting a full year can cost you options. Raise it with a clinician sooner.

If your periods are irregular or absent, or you have a known condition, get checked early - regardless of how long you've been trying. Irregular ovulation is one of the most common and most treatable causes of difficulty conceiving.

The thread running through all of it: the months before you reach a clinic are not wasted time. Used well, they're where you give yourself the best odds - and where good tracking pays off most.

Why age keeps coming up

The reason 36 is a turning point in the guidance comes down to ovarian biology, and a 2025 ACOG committee statement on anticipatory counselling for fertility decline lays it out clearly.

Female fertility decreases gradually from around age 32, then more steeply after 37. That's driven by the natural drop in both the number and quality of eggs over time. The egg count falls from roughly 300,000 to 500,000 at puberty to about 25,000 by age 37 and around 1,000 by age 51, the average age of menopause.

ACOG's other key point: many people overestimate their monthly odds of conceiving, partly because of misleading information online. Knowing your real timeline isn't meant to cause alarm - it's so you can make decisions, including about fertility preservation, with accurate expectations rather than optimistic guesses.

None of this means conceiving after 35 is rare - it's extremely common. It means the timing of when to seek help shifts earlier, which is exactly what NG257 codifies.

Signs it's worth getting assessed sooner

See a clinician before the standard wait if you notice any of these:

• Periods shorter than 21 days or longer than 35 days, or that skip entirely - a sign ovulation may be irregular, common with PCOS/PMOS
• No detectable ovulation across several tracked cycles
• Painful periods or pain during sex, which can point to endometriosis
• A history of pelvic infection, pelvic surgery, or cancer treatment in either partner
• You're 36 or older and have started trying
• Known male-factor concerns such as previous testicular surgery or low semen analysis results

Raising any of these early isn't jumping the gun. Under the new guidance, it's exactly what the pathway is designed for.

What to do before you need a clinic

These are the highest-leverage steps in the months before any referral - and the ones that make a later clinic visit far more productive.

1. Learn your cycle length. Count from the first day of one period to the first day of the next, across a few cycles. The Menstrual Cycle Calculator gives you a baseline, and a regular, predictable cycle is itself reassuring evidence that you're ovulating.
2. Find and target your fertile window. Conception is only possible on about six days each cycle. Use the Ovulation Calculator and Fertile Window Calculator to map those days, and aim for the two to three days before ovulation. Our guide to ovulation symptoms shows how to confirm timing from your own body.
3. Act on the lifestyle basics now. Folic acid before conception, a healthy BMI, and cutting smoking and heavy alcohol are the same things NICE puts at the front of the pathway. They matter for both partners.
4. Track consistently from the start. When you do see a clinician, months of logged cycles, symptoms, and timing turn a vague "we've been trying" into concrete data they can act on.
5. Know your threshold and hold yourself to it. Under 36, mark a year on the calendar. Thirty-six or older, or with any risk factor, make the appointment early. Don't let the months drift.

How Femora helps

The single most useful thing you can bring to a fertility assessment is a clear record of your own cycle - and that's what Femora is built to capture.

• Fertile window and ovulation predictions - calculated from your own logged cycles, so your timing sharpens month over month
• Cycle ring dashboard - see at a glance whether you're heading into your fertile window
• Symptom and ovulation logging - cervical fluid, mid-cycle pain, and cycle length in one place, the exact signals that flag whether ovulation is regular
• Exportable history - hand your clinician data instead of guesses, which is precisely what the new primary-care-first pathway runs on

Pair the app with the Ovulation Calculator, Fertile Window Calculator, and Conception Date Calculator for quick one-off estimates, and the Due Date Calculator for when it works.

The bigger picture

NG257 doesn't change the biology of conception. What it changes is the timing of action: assess earlier, start in primary care, and match the plan to the person. Treating your cycle as the data source it already is - knowing your length, your fertile window, and your own normal - is how you make those months count, whether you conceive on your own or walk into a clinic already holding the evidence they need.

Track your cycle and fertile window with Femora. Free on iOS and Android.

Sources

• Fertility problems: assessment and treatment (NG257) - NICE, March 31, 2026
• Defining infertility and initial assessment, NG257 - NICE, 2026
• Anticipatory Counseling Regarding Ovarian-Factor Fertility Decline - ACOG Committee Statement, November 2025
• Having a Baby After Age 35: How Aging Affects Fertility and Pregnancy - ACOG
• Infertility - NHS, 2023