Endometriosis And Pregnancy

One of the most common gynecological diseases is endometriosis. This disease is characterized by the growth of endometrial tissue, the inner layer of the uterine walls, outside the uterus1

Approximately 10% of reproductive-aged women in the world are affected by endometriosis with 25-50% of women with endometriosis reporting infertility1.

Given the prevalence of the disease, very few women are free from risk. Endometriosis can significantly and negatively affect both conception and the progress of pregnancy. If it is ignored, endometriosis can lead to infertility1.


Although the exact cause of endometriosis is not certain, possible explanations include2:

  • Menstrual disorders. 
  • Hormonal disorders that lead to cell transformation.
  • Surgical scar implantation. Endometrial cells may attach to a surgical incision after an operation such as a hysterectomy or C-section.
  • Endometrial cell transport. This can occur when endometrial cells are carried away from the endometrium to other parts of the body through blood vessels or the tissue fluid (lymphatic) system.
  • Immune system disorder. A problem with the immune system may make the body unable to recognise and destroy endometrial-like tissue growing outside the uterus.

Risk factors

Several factors place you at greater risk of developing endometriosis, including2:  

  • Not having given birth; 
  • Starting your periods at an early age;
  • Going through the menopause at an older age; 
  • Short menstrual cycles — for instance, less than 27 days; 
  • Heavy menstrual periods that last longer than seven days; 
  • Having higher levels of estrogen in your body or greater lifetime exposure to estrogen that your body produces; 
  • Low body mass index (BMI); 
  • One or more relatives (mother, aunt or sister) with endometriosis;
  • Any medical condition that prevents the passage of blood from the body during menstrual periods; 
  • Disorders of the reproductive tract.


The primary symptom of endometriosis is pelvic pain, often associated with menstruation. Although many women experience cramping during their periods, those with endometriosis typically describe menstrual pain that is much worse than usual. Pain may also increase over time2.  

Common signs and symptoms of endometriosis include2:

  • Painful periods (dysmenorrhea). 
  • Pain during intercourse. 
  • Pain during bowel movements or urination. 
  • Excessive bleeding.
  • Infertility.
  • Other signs and symptoms include fatigue, diarrhea, constipation, bloating or nausea, especially during menstruation.


The main complication of endometriosis is impaired fertility. Approximately one-third to half of all women with endometriosis in the world have difficulty getting pregnant2.

For pregnancy to occur, an egg must be released from an ovary, then travel through the neighbouring fallopian tube, after which it is fertilised by a sperm cell before attaching itself to the uterine wall where it begins to develop.

Endometriosis may obstruct the tube and prevent the egg and sperm from uniting. But the condition can also affect fertility indirectly by damaging the sperm or egg2.

Despite this, many women with mild to moderate endometriosis can still conceive and carry a pregnancy to term. Doctors sometimes advise those with endometriosis not to delay having children because the condition may become worse over time2.

Diagnosis and treatment

Tests to check for physical clues of endometriosis include3:

  • Pelvic exam
  • Ultrasound
  • Magnetic resonance imaging (MRI)
  • Laparoscopy

Treatment for endometriosis usually involves medication or surgery. Doctors typically recommend trying conservative treatment approaches first, opting for surgery only if initial treatment fails3.

Hormone therapy

Supplemental hormones are sometimes effective in reducing or eliminating the pain of endometriosis. The rise and fall of hormones during the menstrual cycle causes endometrial implants to thicken, break down and bleed. Hormone medication may slow endometrial tissue growth and prevent new implants of endometrial tissue3.

Fertility treatment

Endometriosis can impair the ability to conceive. Fertility treatment ranges from stimulating ovaries to make more eggs to in vitro fertilisation. Deciding which treatment approach to take depends upon each patient’s personal situation3.

See your doctor if you have signs and symptoms that may indicate endometriosis.


  1. Navarro, R., Poder, L., Sun, D., & Jha, P. (2020). Endometriosis in pregnancy. Abdominal Radiology. doi:10.1007/s00261-020-02486-7.
  2. Endometriosis. https://www.mayoclinic.org/diseases-conditions/endometriosis/symptoms-causes/syc-20354656 (Last access 14.06.2022).  
  3. Endometriosis. https://www.mayoclinic.org/diseases-conditions/endometriosis/diagnosis-treatment/drc-20354661 (Last access 14.06.2022).