Endometriosis and fertility

What is endometriosis, and why does it affect fertility?

Endometriosis is a condition in which tissue similar to the lining of the uterus grows outside it, most often on the ovaries, fallopian tubes, and the tissue lining the pelvis. This misplaced tissue responds to your monthly hormone cycle just like the uterine lining does, thickening and breaking down each month, but with nowhere to shed to. Over time this can cause inflammation, scar tissue, and adhesions that distort the normal position of your ovaries and tubes. It's one of the more common findings among women being evaluated for infertility, though plenty of people with endometriosis conceive without any treatment at all.

The link to fertility comes from several overlapping mechanisms rather than one single cause. Inflammation in the pelvis can affect egg quality, how well the fallopian tube picks up an egg after ovulation, and how receptive the uterine lining is to an embryo. In more advanced cases, scar tissue can physically block or distort the fallopian tubes, or cause an endometrioma — a cyst filled with old blood, sometimes called a "chocolate cyst" — on an ovary. None of these mechanisms mean pregnancy is impossible; they mean the path to it can be less straightforward and worth understanding early.

How much does endometriosis actually lower your chances of pregnancy?

Endometriosis is associated with a longer average time to pregnancy and, in moderate to severe cases, a lower chance of conceiving without treatment, but many people with the condition — including some with significant disease — become pregnant naturally. The effect on any individual depends heavily on the stage and location of the tissue, your age, and whether the fallopian tubes are affected. A mild case found incidentally during unrelated surgery may have little bearing on your fertility at all. A severe case with large endometriomas or blocked tubes is more likely to need medical help to conceive.

This is why doctors talk about endometriosis in terms of probability and typical patterns rather than a fixed verdict on any one person. Two people with the same stage of disease can have very different experiences trying to conceive. Age compounds the picture too — the same degree of endometriosis tends to have a bigger impact on someone in their late 30s than in their late 20s, simply because egg quantity and quality are already declining with age on their own. A diagnosis is information to act on, not a prediction of what will happen to you specifically.

What are the signs of endometriosis you shouldn't ignore?

The most common signs are pelvic pain that's worse around your period, pain during or after sex, pain with bowel movements or urination especially during your period, and periods that are unusually heavy or irregular. Fatigue and digestive symptoms like bloating or nausea around your period are also common but easy to mistake for other things. Some people have no pain at all and only discover endometriosis while being investigated for difficulty conceiving. Because symptoms vary so widely, the absence of pain doesn't rule endometriosis out, and its presence doesn't confirm it either.

Call your provider the same day for pelvic pain severe enough to stop you from working or functioning normally, heavy bleeding that soaks through a pad or tampon every hour for several hours, or new pain accompanied by fever, fainting, or vomiting. These can signal a ruptured endometrioma or another condition needing urgent attention, not just a bad period. Long-standing period pain that you've simply learned to live with is also worth raising at a routine visit — many people wait years before mentioning it, and earlier evaluation gives more options, not fewer.

How is endometriosis diagnosed and staged?

A definitive diagnosis of endometriosis requires laparoscopy, a minor surgical procedure where a doctor looks inside the pelvis with a small camera and can take a tissue sample, though many providers start with a pelvic exam and imaging first. Ultrasound and MRI can pick up larger endometriomas and some deep disease but often miss smaller or superficial patches of tissue. Because of this, a normal scan doesn't fully rule out endometriosis, and many providers will treat based on symptoms and history before pursuing surgery. Staging, from I (minimal) to IV (severe), describes how much tissue is present and where.

Stage doesn't reliably predict fertility impact, which surprises a lot of people. Someone with stage I disease can struggle to conceive, while someone with stage IV disease conceives without difficulty — location and the involvement of the ovaries or tubes often matter more than the total amount of tissue. The table below shows the general pattern doctors describe, not a rule for any individual case.

| Stage | Extent of tissue | Typical fertility consideration | |---|---|---| | I – Minimal | Small, scattered implants | Often limited effect on natural conception | | II – Mild | More implants, shallow | May have modest effect | | III – Moderate | Deeper implants, possible small endometriomas | Effect varies widely by location | | IV – Severe | Extensive disease, larger endometriomas, adhesions | More often associated with reduced natural conception |

What treatments can help you conceive with endometriosis?

Treatment options range from laparoscopic surgery to remove or destroy endometrial tissue and scar tissue, to fertility treatments like ovulation induction, intrauterine insemination (IUI), or in vitro fertilization (IVF), depending on the severity of disease and how long you've been trying. Surgery can improve natural conception rates for some people, particularly when adhesions or an endometrioma are distorting the pelvic anatomy, though it isn't right for everyone and carries its own risks and recovery time. IVF is often recommended when tubes are affected or when other treatments haven't worked, because it bypasses the fallopian tubes entirely. Your provider can weigh these options against your specific findings, age, and how long you've been trying.

It's worth knowing that hormonal treatments commonly used to manage endometriosis pain — like birth control pills, progestins, or GnRH agonists — work by suppressing ovulation, so they need to be paused while you're actively trying to conceive. This can feel like an unfair trade-off if the medication had been controlling your pain well. Talk to your provider about a plan for symptom management during the months you're trying, since stopping treatment doesn't have to mean stopping all support for pain. Fertility specialists who treat endometriosis regularly can usually offer options that weren't available at the point of your original diagnosis.

When should you seek help if you have endometriosis and are trying to conceive?

If you already have a diagnosis of endometriosis, most providers suggest seeking a fertility evaluation sooner than the standard 12-month guideline — often after about 6 months of trying, or right away if you're 35 or older or have known tubal involvement. This isn't because pregnancy is unlikely; it's because endometriosis is a known risk factor, and earlier information gives you and your provider more options to work with. Our guide to [fertility evaluation](/getting-pregnant/fertility-evaluation) explains what that first visit typically involves. Waiting to see what happens rarely helps once endometriosis is already part of the picture.

Seek care sooner rather than later if you have severe or worsening pelvic pain, pain that's begun interfering with daily life, or if you notice new symptoms like pain during bowel movements that weren't there before. If you're also weighing age as a factor — many people with endometriosis are also weighing the effects covered in our [age and fertility](/getting-pregnant/age-and-fertility) guide — the two considerations often point toward the same advice: don't wait longer than you need to. A same-day call is warranted for sudden, severe pelvic pain, fever, or fainting, which can indicate a ruptured cyst or another urgent problem.

What can you do if you have endometriosis and want to conceive?

Track your cycle and time intercourse around your fertile window using a tool like babybumpkit's [ovulation calculator](/ovulation-calculator), since knowing your fertile days matters even more when time may feel more limited. Keep a simple record of your pain patterns and cycle length to share with your provider — it speeds up the evaluation process and helps distinguish typical period pain from something that needs a closer look. If you haven't already had imaging or a laparoscopy, ask specifically about endometriosis if you have any of the symptoms above, since it's still under-diagnosed and often takes years to identify.

If you're actively trying, babybumpkit's [conception calculator](/conception-calculator) can help you estimate your fertile window and plan around it while you pursue evaluation in parallel — the two aren't mutually exclusive. None of these tools change the underlying biology, but using your fertile days well while you wait for appointments or test results is a reasonable thing to do. If anxiety about endometriosis and fertility is affecting you, say so plainly to your provider; they can tell you what's realistic for your specific stage and history, which general information like this can't.

Frequently asked questions