Endometriosis and Fertility
Understanding how endo affects conception—and what you can do about it.
Key Facts
- Prevalence: 30-50% of women with infertility have endometriosis
- Conception possible: Many women with endo conceive naturally or with treatment
- Severity varies: Stages I-II have better natural conception rates than III-IV
- Treatment works: Surgery can improve fertility; IVF success rates are good
What Is Endometriosis?
Endometriosis occurs when tissue similar to the uterine lining (endometrium) grows outside the uterus—on the ovaries, fallopian tubes, pelvic lining, and sometimes beyond.
This misplaced tissue responds to hormonal cycles just like the uterine lining, thickening and breaking down each month. But unlike menstrual blood, it has no way to exit the body, leading to inflammation, scar tissue, and adhesions.
Common Symptoms
- Painful periods (dysmenorrhea)—often severe
- Pain during or after sex
- Pain with bowel movements or urination
- Heavy periods or bleeding between periods
- Chronic pelvic pain
- Fatigue
- Difficulty getting pregnant
⚠️ Diagnosis Delay
On average, it takes 7-10 years from symptom onset to diagnosis. Many women are told their pain is "normal." If you have severe menstrual pain, pain during sex, or fertility issues, advocate for investigation.
How Endometriosis Affects Fertility
Endometriosis can impact fertility through multiple mechanisms:
Anatomical Distortion
- Blocked tubes: Adhesions can block or distort fallopian tubes
- Ovarian damage: Endometriomas (chocolate cysts) can harm ovarian tissue
- Altered anatomy: Scar tissue can prevent egg pickup or transport
Inflammatory Environment
- Chronic inflammation affects egg and sperm quality
- Inflammatory factors may impair implantation
- Peritoneal fluid may be toxic to sperm
Egg Quality & Ovarian Reserve
- Endometriomas may reduce the number of healthy eggs
- Surgery for endometriomas can also reduce ovarian reserve
- Some studies suggest lower egg quality in endo patients
Implantation Issues
- The endometrium may be less receptive to embryos
- Progesterone resistance may occur
Stages of Endometriosis
Endometriosis is staged I-IV based on location, extent, and depth of implants, as well as presence of adhesions and ovarian cysts. Staging is done during surgery.
Minimal
Small, superficial implants. Few or no adhesions. Monthly fecundity (per-cycle pregnancy rate) estimated at 8-10%—slightly below normal but natural conception very possible.
Mild
More implants, deeper than Stage I. May have mild adhesions. Monthly fecundity similar to Stage I (~8-10%). Most women can still conceive naturally, though it may take longer.
Moderate
Deep implants, small endometriomas on one or both ovaries, filmy adhesions. Monthly fecundity drops to ~3-5%. Treatment often recommended to improve chances.
Severe
Large endometriomas, extensive adhesions, deep infiltrating disease. Monthly fecundity ~1-3%. Usually requires surgical and/or IVF treatment.
🔬 Stage ≠ Pain
Importantly, the stage of endometriosis does NOT correlate with pain severity. Some women with Stage I have debilitating pain, while some with Stage IV have minimal symptoms. Staging primarily guides fertility treatment decisions.
Treatment Options for Fertility
🔬 Expectant Management (Trying Naturally)
Best for: Stages I-II with open tubes, no other fertility factors, younger age
For mild endo, trying naturally for 6-12 months (depending on age) is reasonable. Monthly pregnancy rates are reduced but not zero.
Success: Cumulative pregnancy rate of 40-50% over 2-3 years for minimal/mild endo.
🔧 Laparoscopic Surgery
Best for: Stages I-III to improve natural conception; removing endometriomas before IVF
Excision or ablation of endometriosis lesions can improve fertility, especially in mild-moderate disease. Surgery for endometriomas is more controversial due to ovarian reserve impact.
Success: Surgery for Stage I-II doubles monthly pregnancy rates (from ~2-3% to ~5-7%). For Stage III-IV, improvements are less dramatic but still beneficial.
💡 Timing Matters
Fertility tends to be best in the 6-12 months after surgery, before endo potentially regrows. Many doctors recommend trying to conceive actively during this window.
💊 Ovulation Induction + IUI
Best for: Stages I-II with open tubes
Clomid or Letrozole plus IUI can improve pregnancy rates for minimal-mild endo. Less effective for moderate-severe disease.
Success: ~8-15% per cycle for Stage I-II.
🧬 IVF
Best for: Stages III-IV, failed other treatments, tubal damage, or combined with other fertility factors
IVF bypasses many of the anatomical issues caused by endo. Success rates are slightly lower than for other diagnoses but still good.
Success: ~35-45% live birth rate per transfer (varies by age). Women with endo may need higher medication doses and may retrieve fewer eggs, but embryo quality is often good.
Treatment Comparison
| Treatment | Best for Stages | Per-Cycle Success |
|---|---|---|
| Natural Conception | I-II | 8-10% |
| Post-Surgery Natural | I-III | 5-7% (improved from baseline) |
| Clomid/Letrozole + IUI | I-II | 8-15% |
| IVF | All stages | 35-45% (per transfer) |
Special Considerations
Endometriomas (Chocolate Cysts)
These ovarian cysts filled with old blood are common in endo. The decision to remove them surgically is complex:
- Pros of removal: Improves access to follicles during IVF, may improve egg quality
- Cons of removal: Surgery removes healthy ovarian tissue too, reducing egg reserve
- Current thinking: For IVF, small endometriomas (<4cm) are often left alone. Larger ones or those causing symptoms may warrant removal.
Adenomyosis
Adenomyosis (endometrial tissue growing into the uterine muscle) often coexists with endometriosis. It may affect implantation and increase miscarriage risk. Treatment is more limited, but IVF with proper management can still succeed.
Recurrence
Endometriosis can recur after surgery. Pregnancy itself often suppresses endo temporarily. If conception is a goal, prioritizing fertility treatment over long-term suppressive therapy often makes sense.
Lifestyle & Supportive Care
While these won't cure endo, they may help manage symptoms and support overall fertility:
- Anti-inflammatory diet: Reduce red meat, increase omega-3s, fruits, vegetables
- Avoid endocrine disruptors: Limit plastics, choose organic when possible
- Exercise: Regular, moderate activity may reduce symptoms
- Stress management: Chronic pain is stressful; support your mental health
- Supplements: Omega-3s, NAC, and curcumin show some promise (discuss with doctor)
💡 Finding the Right Doctor
Not all OB/GYNs are experienced with endo. Look for an RE (reproductive endocrinologist) for fertility issues, or an endo specialist/excision surgeon if surgery is needed. Quality of surgery matters significantly for outcomes.
The Bottom Line
Endometriosis makes conception harder—but not impossible. Many women with endo become pregnant, whether naturally, with surgical help, or through IVF. The key is getting properly diagnosed, understanding your stage, and working with specialists who know endo.
Your pain is real, your fertility concerns are valid, and there are paths forward. 💚