Endometriosis does make it harder to get pregnant, but it doesn’t make it impossible. Between 30% and 50% of people with endometriosis experience infertility, and the monthly chance of conceiving drops significantly. In a typical cycle, someone without endometriosis has roughly a 15% to 20% chance of becoming pregnant. With endometriosis, that number falls to somewhere between 2% and 10%.
Those numbers can feel discouraging, but they tell only part of the story. Many people with endometriosis do conceive, some without any medical help at all. How difficult it is depends on the severity of the disease, which organs are affected, and how long you’ve been trying.
How Endometriosis Interferes With Fertility
Endometriosis affects conception through several overlapping mechanisms, not just one. The tissue that resembles the uterine lining grows in places it shouldn’t, most commonly on the ovaries, fallopian tubes, and the tissue lining the pelvis. Each month, this tissue responds to hormonal shifts the same way the uterine lining does, but it has no way to exit the body. The result is chronic irritation that builds over time.
One of the most direct effects is scar tissue. Repeated cycles of inflammation cause adhesions, bands of fibrous tissue that can bind organs together or block the fallopian tubes. When tubes are partially or fully blocked, the egg and sperm can’t meet. Even when the tubes are open, adhesions can distort the anatomy enough to make it harder for the ovary to release an egg into the tube normally.
But the damage goes beyond physical blockages. Endometriosis creates a hostile chemical environment inside the pelvis. The fluid that surrounds the reproductive organs becomes loaded with immune cells and inflammatory signals. These immune cells can directly interfere with sperm movement, reduce the chances of an egg being fertilized, and even slow the growth of early embryos. Research shows that embryos exposed to this inflammatory environment are less likely to develop normally through the critical early cell-division stages.
The Impact on Egg Supply
When endometriosis forms cysts on the ovaries, called endometriomas, it can damage the surrounding egg-containing tissue. This is a concern even before any treatment begins, because the cyst itself may compress and harm nearby follicles.
Surgery to remove endometriomas adds another layer of risk. A large meta-analysis found that removing these cysts caused a significant drop in ovarian reserve, a measure of how many eggs remain. The marker doctors use to estimate this reserve (called AMH) fell by about 35% to 54% after surgery, depending on when it was measured. This happens because the procedure inevitably removes some healthy ovarian tissue along with the cyst wall. For someone already thinking about fertility, this tradeoff between removing the cyst and preserving eggs is an important conversation to have with a specialist before surgery.
Does the Stage of Endometriosis Matter?
Endometriosis is classified into four stages, from minimal (stage I) to severe (stage IV), based on the location, depth, and extent of the tissue. More advanced disease generally correlates with greater fertility challenges, but the relationship isn’t always straightforward. Some people with mild endometriosis struggle to conceive, while others with severe disease get pregnant without intervention.
That said, the numbers do shift with severity. IVF outcomes illustrate this clearly: in one study comparing people with stage III or IV endometriosis to those with a different cause of infertility (blocked tubes), the endometriosis group had a live birth rate per cycle of about 7%, compared to nearly 17% in the other group. Advanced endometriosis affects not just the anatomy but also egg quality and how well embryos implant, which is why even bypassing the tubes with IVF doesn’t fully level the playing field.
Conceiving After Surgery
For many people, surgical removal of endometriosis lesions improves the odds of natural conception. In a large analysis of patients who had laparoscopic surgery for endometriosis-related infertility, the overall pregnancy rate within one year was 57.3%. The highest rates occurred between three and six months after surgery, which is why fertility specialists often recommend trying soon after recovery.
Even for early-stage disease, surgery can help. A major randomized trial found that surgically treating mild endometriosis lesions nearly doubled spontaneous pregnancy rates compared to doing nothing: about 31% conceived after treatment versus 18% in the group that had only a diagnostic procedure. This suggests that even small, seemingly minor lesions can meaningfully interfere with fertility.
The window after surgery tends to close over time, though, as endometriosis can grow back. If conception doesn’t happen within six to twelve months post-surgery, moving to assisted reproduction is a common next step.
Fertility Treatment Options
When natural conception doesn’t work, the most common paths are medicated cycles (using hormones to stimulate ovulation, sometimes paired with intrauterine insemination) and IVF. Which approach makes sense depends on your age, how long you’ve been trying, and the extent of the disease.
IVF is often recommended earlier for people with endometriosis than for other causes of infertility, particularly when there’s damage to the tubes or ovaries, or when milder treatments haven’t worked after a few cycles. While IVF success rates are somewhat lower for people with advanced endometriosis compared to other diagnoses, it remains the most effective option for many. Some clinics prescribe a period of hormone suppression before starting an IVF cycle to calm inflammation and improve the uterine environment, though protocols vary.
Because endometriomas and their surgical removal can reduce egg supply, some people choose to freeze eggs or embryos before undergoing surgery, preserving their options for later.
Timing and When to Get Help
The general advice for most couples is to try for a year before seeking fertility evaluation, or six months if you’re over 35. But endometriosis changes that calculus. Clinical guidelines recommend that people with known endometriosis be referred to a reproductive endocrinologist on an expedited basis, meaning you don’t need to wait the standard timeline before getting specialized help.
If you’ve been diagnosed with endometriosis and are thinking about pregnancy, an early consultation with a fertility specialist can help you understand your individual situation. Testing your ovarian reserve, checking whether your tubes are open, and reviewing imaging for endometriomas gives you a clearer picture of what you’re working with. Starting that process sooner rather than later matters, because both endometriosis progression and age work against fertility over time.