What the evidence and ESHRE guidelines actually tell us

One of the most common questions I hear from women with endometriosis who are trying to conceive is:

“Should I have surgery first, or should I go straight to IVF?”

It sounds like it should have a simple answer.

It doesn’t.

For some women, surgery may improve the chance of conceiving naturally.

For others, particularly when time is important or ovarian reserve is already reduced, surgery may delay effective fertility treatment — and ovarian surgery itself can sometimes reduce the number of eggs remaining.

And for some women, the best approach may be neither immediate surgery nor immediate IVF.

The decision depends on much more than simply whether endometriosis is present.

Age, ovarian reserve, pain, the location and severity of endometriosis, previous surgery, fallopian tube function, sperm quality, how long a couple has been trying and their reproductive plans all matter.

That is why I don’t believe the question should simply be:

“Do you have endometriosis?”

The better question is:

“What is the best way for this particular woman to achieve a healthy pregnancy while protecting her future fertility?”

How does endometriosis affect fertility?

Endometriosis can affect fertility in several ways.

In more severe disease, inflammation, adhesions and distorted pelvic anatomy may interfere with the relationship between the ovary and fallopian tube.

Endometriosis involving the ovaries can form endometriomas, sometimes called “chocolate cysts”.

Endometriosis may also affect the ovarian environment, egg numbers and potentially aspects of fertilisation and implantation.

But an important point is often lost:

Having endometriosis does not automatically mean you need IVF.

Many women with endometriosis conceive naturally.

The challenge is identifying who has time to continue trying naturally, who might benefit from surgery, and who would lose valuable reproductive time by delaying fertility treatment.

Does surgery improve natural fertility?

For minimal or mild endometriosis, we actually have randomised trial evidence.

One of the landmark studies was the Canadian Collaborative Group trial published by Marcoux and colleagues in the New England Journal of Medicine in 1997.

The study randomised 341 infertile women with minimal or mild endometriosis to either surgical treatment of visible endometriosis or diagnostic laparoscopy alone.

Pregnancies continuing beyond 20 weeks occurred in:

• 30.7% after surgical treatment
• compared with
• 17.7% after diagnostic laparoscopy alone

The fecundity rate was almost twice as high following operative treatment.

This study helped establish that treating minimal or mild endometriosis surgically can improve the chance of subsequent pregnancy in appropriately selected women.

A later Cochrane review incorporating randomised trials reached a similar conclusion: laparoscopic treatment probably increases viable intrauterine pregnancy compared with diagnostic laparoscopy alone.

However, there is an important limitation.

The trials did not provide good live-birth data, and much of the evidence relates to relatively mild disease.

So surgery can improve natural conception in some women — but this does not mean every woman with endometriosis should undergo laparoscopy before fertility treatment.

What does the ESHRE guideline recommend?

The 2022 European Society of Human Reproduction and Embryology (ESHRE) guideline on endometriosis moved the discussion away from a “one treatment fits all” approach.

For infertility associated with Stage I/II endometriosis, operative laparoscopy can be offered because it may improve ongoing pregnancy rates.

But ESHRE recommends that the decision about surgery should also consider:

• the woman’s age
• ovarian reserve
• pain symptoms
• previous surgery
• other infertility factors
• the woman’s preferences
• and the Endometriosis Fertility Index (EFI)

This is important.

The presence of endometriosis alone is not enough to decide whether surgery is the right fertility treatment.

What is the Endometriosis Fertility Index?

The Endometriosis Fertility Index (EFI) is a clinical tool designed to estimate the likelihood of natural pregnancy after endometriosis surgery.

It incorporates factors such as age, duration of infertility, previous pregnancy history, disease severity and the function of the ovaries, tubes and fimbriae after surgery.

A woman with a favourable EFI may have a reasonable chance of conceiving naturally after surgery.

Someone with a low EFI may be better served by moving more quickly towards assisted reproduction.

ESHRE recommends using the EFI, together with other fertility investigations including sperm assessment, when counselling women about fertility after surgery.

What about an ovarian endometrioma?

This is where the discussion becomes particularly important.

When an ultrasound shows an ovarian endometrioma, it can be very tempting to think:

“There is a cyst. Let’s remove it before IVF.”

But fertility treatment is not quite that simple.

An endometrioma is within the ovary — the same ovary containing the woman’s remaining eggs.

Removing the cyst can inadvertently remove or damage healthy ovarian tissue.

Multiple studies have demonstrated a reduction in AMH (anti-Müllerian hormone) following endometrioma surgery, particularly after bilateral ovarian surgery.

A systematic review and meta-analysis examining 36 studies found significant reductions in AMH in the short, medium and long term following endometrioma surgery, with greater effects after bilateral surgery.

So when fertility is the priority, we have to balance two competing considerations:

• the possible benefit of treating the endometriosis
• against
• the possibility of reducing ovarian reserve

Should an endometrioma be removed before IVF?

Not routinely.

This is one of the clearest messages from the current ESHRE guideline.

ESHRE does not recommend routinely performing surgery for an ovarian endometrioma before assisted reproductive treatment simply to improve live-birth rates.

Why?

Because the available evidence has not demonstrated that removing an endometrioma before IVF improves the chance of having a baby — while surgery can negatively affect ovarian reserve.

A major systematic review and meta-analysis by Hamdan and colleagues examined IVF/ICSI outcomes in women with endometriomas.

Women with endometriomas had similar live-birth and clinical pregnancy rates to women without endometriomas, although fewer eggs were retrieved on average.

Importantly, when women who underwent surgery before IVF were compared with women who did not have their endometrioma surgically treated, surgery did not improve live-birth rates.

That finding fundamentally changes the conversation.

A cyst being visible on ultrasound does not automatically mean it should be removed before IVF.

When might I still recommend surgery before IVF?

There are situations where surgery can still be entirely appropriate.

For example:

• Significant pain
  If endometriosis is causing substantial pelvic pain, painful intercourse or affecting quality of life, the decision is no longer purely about improving IVF statistics.
• Difficulty accessing the follicles
  Occasionally, the position or size of an endometrioma may make safe egg collection technically difficult.
• Suspicious ovarian features
  If imaging raises concern that an ovarian lesion may not represent a straightforward benign endometrioma, further assessment and sometimes surgery may be necessary.
• Deep endometriosis
  Deep infiltrating endometriosis involving the bowel, bladder or other pelvic structures requires a much more individualised discussion. Surgery can significantly improve symptoms for some women. But importantly, evidence that operating on deep endometriosis before IVF improves reproductive outcomes remains uncertain. ESHRE therefore recommends that the decision should primarily be guided by symptoms and patient preference rather than performing surgery routinely in the hope of improving IVF success.

When might I favour IVF rather than surgery?

There are several situations where I would be particularly cautious about delaying fertility treatment for surgery.

• Age
  Age remains one of the strongest determinants of reproductive potential. For a woman in her late 30s, spending many months undergoing surgery and then attempting natural conception may carry a very different reproductive cost from the same strategy in a 28-year-old. We can treat endometriosis. We cannot reverse reproductive ageing.
• Reduced ovarian reserve
  If AMH and antral follicle count are already low, ovarian surgery requires careful consideration. The aim should be to avoid reducing an already limited egg reserve unless surgery has a clear indication.
• Bilateral endometriomas
  Operating on both ovaries can pose a greater risk to ovarian reserve than unilateral surgery.
• Previous ovarian surgery
  Repeated surgery on the same ovary deserves particular caution.
• Blocked or significantly damaged fallopian tubes
  Even excellent endometriosis surgery may not restore normal fertility if tubal function is substantially compromised.
• Significant male-factor infertility
  If ICSI is likely to be required because of sperm factors, surgery solely to improve natural conception may offer relatively little benefit.
• Low Endometriosis Fertility Index
  A low EFI following surgery suggests that prolonged attempts at natural conception may not be the best use of reproductive time.

Does IVF make endometriosis worse?

This is another question I am frequently asked.

Women sometimes worry that the high oestrogen levels occurring during ovarian stimulation will accelerate their endometriosis.

Current evidence is reassuring.

ESHRE states that women with endometriosis can be reassured about the safety of assisted reproductive treatment because ART does not appear to increase endometriosis recurrence rates compared with women who do not undergo ART.

This is particularly important for women who have delayed IVF because they are frightened of “feeding” their endometriosis.

Do women with endometriosis need a special IVF protocol?

Not necessarily.

There has been considerable interest in whether women with endometriosis should have prolonged down-regulation before IVF or whether a particular stimulation protocol is superior.

Current ESHRE guidance does not recommend one specific ovarian stimulation protocol for women with endometriosis.

Both GnRH antagonist and agonist protocols can be used.

Importantly, prolonged GnRH agonist treatment before IVF specifically to improve live-birth rates is not routinely recommended, because the benefit remains uncertain.

Treatment should therefore be individualised according to ovarian reserve, previous response, age and the overall clinical situation rather than applying an “endometriosis protocol” to every patient.

What about medical treatment instead of surgery or IVF?

Hormonal treatments can be very effective for controlling endometriosis-associated pain.

But there is an important distinction between:

• treating endometriosis symptoms
• and
• treating infertility.

Ovarian suppression prevents ovulation while it is being used.

ESHRE therefore recommends against ovarian-suppression treatment simply to improve fertility in infertile women with endometriosis.

If the immediate goal is pregnancy, months of suppressing ovulation do not by themselves increase natural fertility.

Surgery or IVF? My approach

I don’t believe every woman with endometriosis should be sent directly to IVF.

Equally, I don’t believe every visible endometrioma needs to be surgically removed before fertility treatment.

I usually start with several questions.

• How old is she?
• How long has she been trying?
• How much pain does she have?
• What is her ovarian reserve?
• Is the disease affecting one ovary or both?
• Has she already had ovarian surgery?
• Are the fallopian tubes functional?
• What does the sperm assessment show?
• Does she want one child or potentially several children?

And perhaps most importantly:

How much reproductive time can we safely afford to spend?

A 29-year-old with good ovarian reserve, patent tubes, normal sperm and painful Stage I/II disease may reasonably make a very different decision from a 38-year-old with bilateral endometriomas, reduced AMH and two years of infertility.

Both have “endometriosis”.

Their fertility strategy should not automatically be the same.

My take-home message

The question “surgery or IVF?” is the wrong question if it is asked without context.

For some women with mild endometriosis, surgery can improve the chance of natural pregnancy.

For women with significant pain, surgery may have important benefits independent of fertility.

But surgery is not routinely recommended before IVF simply because endometriosis or an endometrioma is present.

In particular, removing an ovarian endometrioma before IVF has not been shown to improve live-birth rates and may reduce ovarian reserve.

For women in whom age, low ovarian reserve, tubal disease, male-factor infertility or previous surgery make time particularly valuable, proceeding towards assisted reproduction may be more appropriate.

The most important decision is therefore not:

“How do we get rid of the endometriosis?”

It is:

“What gives this woman the best chance of achieving the family she wants, while protecting the fertility she still has?”

That is a very different conversation.

Frequently Asked Questions

Should I have endometriosis surgery before trying IVF?

Not routinely. Current ESHRE guidance recommends against surgery before ART solely to improve live-birth rates in women with ovarian endometriomas. Surgery may still be appropriate for significant pain, concerning imaging findings or when an endometrioma makes egg collection difficult.

Can removing an endometrioma reduce my egg reserve?

Yes. Studies measuring AMH before and after endometrioma surgery have demonstrated reductions in ovarian reserve, particularly following bilateral surgery. The individual risk depends on factors including cyst size, whether one or both ovaries are affected, previous surgery and surgical technique.

Can I get pregnant naturally with endometriosis?

Absolutely. Endometriosis does not automatically mean IVF is required. Age, disease severity, ovarian reserve, tubal function, sperm quality and duration of infertility all help determine the likelihood of natural conception.

Does surgery improve fertility in mild endometriosis?

Randomised trial evidence suggests operative laparoscopy for minimal or mild endometriosis can improve subsequent pregnancy rates compared with diagnostic laparoscopy alone. The benefit needs to be considered alongside age and other fertility factors.

Does IVF bypass endometriosis?

IVF can bypass some of the mechanisms through which endometriosis causes infertility — particularly distorted tubo-ovarian anatomy — but it does not remove or cure the underlying endometriosis.

Will IVF make my endometriosis worse?

Current evidence does not show increased recurrence rates from assisted reproductive treatment, and ESHRE considers ART a safe option for women with endometriosis.

Should I freeze eggs if I have an endometrioma?

Not every woman with endometriosis needs fertility preservation. However, ESHRE recommends discussing the advantages and disadvantages of fertility preservation in women with extensive ovarian endometriosis. This discussion can be particularly relevant before ovarian surgery, especially with bilateral or recurrent disease.