IVF at 38–39 occupies a particularly significant clinical position. Success rates have declined measurably from the mid-thirties, but are not yet as low as they will be at 40+. NHS eligibility — which most ICBs cap somewhere between 39 and 42 — is either closing or already at its limit. And for every month of delay in this window, the statistical picture shifts.

This guide is written specifically for patients in this age range — not extrapolated from broader averages that flatten out the details that matter here.

The Numbers at 38–39

HFEA data for patients using their own eggs:

| Age | Live birth rate per embryo transfer | |---|---| | 35–37 | ~25–30% | | 38–39 | ~18–22% | | 40–42 | ~10–14% | | 43–44 | ~5% |

The decline between 35–37 and 38–39 is meaningful — approximately 7–10 percentage points per transfer. Over multiple cycles, cumulative rates are still reasonable: approximately 40–55% over 3 cycles for patients in this range, depending on ovarian reserve.

What the numbers also show: 38–39 is not a cliff edge. Success is still achievable, particularly for patients who begin promptly, have adequate reserve, and who are prepared for the possibility of more than one cycle.

For a detailed explanation of HFEA data, see HFEA success rates explained.

Aneuploidy at 38–39

The chromosomal abnormality rate per egg rises steeply through the late thirties. At 38–39, approximately 50–60% of embryos are aneuploid (chromosomally abnormal), compared to approximately 30–40% at 35–37.

This is the primary reason for the declining success rate — not egg availability (most patients in this range have adequate ovarian reserve for at least a usable stimulated cycle), but egg quality. A higher aneuploidy rate means more cycles produce no transferable euploid embryo, or more transfers fail because the transferred embryo was chromosomally unable to implant.

What this means practically:

  • More cycles may be needed to accumulate a euploid embryo
  • PGT-A (genetic testing of embryos) becomes more clinically relevant in this age group than at 35
  • A single failed cycle does not mean IVF cannot work — it may simply mean the transferred embryo was aneuploid

NHS Eligibility at 38–39

Most ICBs in England have upper age limits for NHS IVF of 39–42. In practice:

  • Many ICBs fund treatment for patients up to their 40th birthday
  • Some ICBs use the age at referral rather than the age at treatment start — which can matter if waiting times push treatment past the threshold
  • Scotland typically uses 40 as the upper limit; Wales 42; Northern Ireland 39

If you are 38–39 and have not yet been referred for NHS IVF, do this now, not in a few months. Ask your GP to expedite the referral given age proximity to NHS eligibility limits. Make it explicit: "I am approaching the age limit for NHS IVF and need an urgent referral."

Check your ICB's current policy at nestie.co/nhs.

Should You Go Straight to IVF?

At 38–39, the case for going directly to IVF — rather than trying IUI or extended natural conception — is stronger than at any younger age:

  • Each month is more valuable than at 35
  • IUI's per-cycle success rate (10–15%) is meaningfully lower than IVF's (~18–22%) and takes the same time per cycle
  • If there are any identifiable factors (endometriosis, male factor, low AMH), IVF is almost certainly more appropriate than IUI
  • The diagnostic information from an IVF cycle (fertilisation rate, embryo development quality, aneuploidy rate if PGT-A is done) is more valuable at this age than at 32

The calculus is different if investigations reveal truly normal parameters with no identifiable cause in a patient who has only been trying for 6 months — but even then, the opportunity cost of 3–6 IUI cycles at 38 is significant.

Ovarian Reserve at 38–39

AMH can vary considerably in this age range. Some patients at 39 have AMH comparable to a 34-year-old; others have significantly reduced reserve. The AMH result is particularly important for treatment planning at this age:

  • Adequate reserve (AMH >10 pmol/L): Standard stimulation protocol, reasonable expected egg yield
  • Low-normal (AMH 5–10 pmol/L): Stimulation will be tailored; expect somewhat fewer eggs
  • Low (AMH <5 pmol/L): Modified protocol; possibly more cycles needed. See low AMH and IVF

PGT-A at 38–39: Is It Worth It?

At this age, PGT-A (embryo genetic testing) becomes a more meaningful clinical consideration than it is at 32–35. With a ~50–60% aneuploidy rate per embryo, transferring untested embryos risks a higher proportion of failed transfers due to chromosomal abnormality.

Arguments for PGT-A at 38–39:

  • Reduces failed transfers from aneuploid embryos (improving per-transfer success rate)
  • Identifies whether any euploid embryos exist in a given cohort — prognostically useful
  • May reduce miscarriage rate (aneuploid embryos are a leading cause of early pregnancy loss)

Arguments against:

  • Adds £2,000–£4,000 to cost
  • Requires freeze-all (no fresh transfer) — adds a cycle
  • Biopsy and freeze slightly reduces the embryo pool
  • If only 1–2 embryos are available, the testing cost per embryo becomes very high

There is no universal answer. Discuss the cost-benefit with your consultant based on your specific situation, number of expected embryos per cycle, and how important it is to you to reduce the chance of a miscarriage from an aneuploid embryo.

See preimplantation genetic testing.

Frequently Asked Questions

Q: I'm 39 next month. Should I rush to start an IVF cycle?

A: If you are approaching your NHS ICB's age limit, yes — initiate the NHS referral immediately. For private IVF, the urgency is about egg quality rather than a policy threshold. Starting a cycle at 39 rather than 40 is clinically meaningful — not because of a hard biological line, but because each year brings a measurable reduction in per-cycle success. If you've been deliberating, 38–39 is not the time to delay further.

Q: I've had one failed IVF cycle at 38. Is it worth trying again?

A: Yes, in most cases. A single failed cycle — particularly if the transferred embryo was not genetically tested — does not predict the outcome of subsequent cycles. Whether to continue, modify the protocol, add PGT-A, or change clinic are all questions worth reviewing with your consultant after a failed cycle. Most of the 40–55% who achieve a baby through IVF in this age group do not do so on the first attempt.

Q: My AMH is normal for my age but my IVF cycle produced few eggs. Why?

A: AMH predicts expected response but doesn't guarantee it. Individual stimulation response can be lower than AMH predicts, particularly in patients who are sensitive to the specific protocol or dose used. This information is useful for the next cycle — the protocol can be adjusted. Discuss with your consultant what the likely explanation is and whether a protocol change is appropriate.

Q: Should I consider donor eggs at 38–39?

A: Not routinely, unless there are specific clinical indications (very low AMH, previous multiple IVF failures, known genetic condition). Most patients at 38–39 with adequate reserve and no prior failed cycles have a reasonable chance with own eggs. Donor eggs become a stronger consideration after multiple own-egg cycle failures, or when AMH is very low and expected yield is minimal. See donor egg IVF in the UK.

Q: Can I do IVF and try naturally at the same time?

A: Yes — natural conception attempts between IVF cycles are both possible and reasonable. IVF cycles typically have a 1–2 month gap between them, and natural conception during this time is not contraindicated. Some patients in this age range conceive naturally between IVF cycles, which is a legitimate outcome to hope for alongside treatment.

This article is for information only and does not constitute medical advice. Success rates are approximate averages; discuss your specific prognosis with your fertility specialist.