What Is Endometriosis?

Getting Pregnant

Obie Editorial Team

What is endometriosis?

Endometriosis is a medical condition that affects the uterus, fallopian tubes, and sometimes other parts of the body. Endometrial tissue grows outside the uterus and can be located on the fallopian tubes, the ovaries, the bowels, bladder, and sometimes even behind the uterus, bowels, or bladder.

The endometrial tissue outside the uterus builds up each month in response to the normal female hormonal cycle, just like the tissue inside the uterus, and at the end of the cycle, it sheds and causes bleeding. But the endometrial tissue outside the uterus has no route for elimination, so the shedding can cause internal bleeding, inflammation, and subsequent scar tissue formation.

This "misplaced" tissue can cause pain, infertility, and very heavy periods. The pain is usually in the abdomen, lower back, or pelvic areas.  

Signs and symptoms of endometriosis

Endometriosis can present as different symptoms, and some women have no symptoms at all. The most common symptoms of endometriosis include:

  • Pain and/or cramps before and during menstrual bleeding (dysmenorrhea)
  • Painful urination during menstrual periods
  • Painful bowel movements during menstrual periods
  • Pelvic pain during sexual intercourse (dyspareunia)
  • Infertility
  • Fatigue
  • Other gastrointestinal upsets such as diarrhea, constipation, nausea

The ultimate diagnosis is made by laparoscopy, a minor surgical procedure done under anesthesia. Without laparoscopy, the diagnosis is uncertain. A laparoscopy usually shows the location, size, and extent of the growths. This helps the doctor and patient make better treatment choices.

How does endometriosis affect fertility?

Having trouble getting pregnant is sometimes the first sign of endometriosis. Women often have difficulty conceiving since the endometriosis grows on the fallopian tubes. This can interfere with the normal function of the fallopian tubes and thus prevent fertilization by either preventing the egg from meeting the sperm or preventing the fertilized egg from moving down the fallopian tubes.

The growths can even rupture and spread to new areas of the body and a build-up of scar tissue can cause adhesions and obstructions.

What causes endometriosis?

The exact cause of endometriosis is not known, but pain medications and hormones can often help. Severe cases may require surgery. There are also treatments to improve fertility in women with endometriosis.

Endometriosis and pregnancy

In addition to fertility problems, women with endometriosis are also at increased risk for several pregnancy complications including:

  • Miscarriage
  • Preterm labor & delivery
  • Placenta previa
  • Recurrent pregnancy loss (RPL) 
  • Complications from endometriomas (eg ovarian cysts)
  • preterm premature rupture of membranes
  • preeclampsia, pregnancy-induced hypertension (PIH)
  • gestational diabetes
  • gestational cholestasis
  • small for gestational age (SGA) babies
  • antepartum hemorrhage
  • postpartum hemorrhage
  • placental abruption
  • retained placenta
  • malpresentation
  • labor dystocia
  • cesarean delivery
  • stillbirth
  • neonatal death
  • congenital malformations of the uterus

Literature: Breintoft K, Pinnerup R, Henriksen TB, Rytter D, Uldbjerg N, Forman A, Arendt LH. Endometriosis and Risk of Adverse Pregnancy Outcome: A Systematic Review and Meta-Analysis. J Clin Med. 2021 Feb 9;10(4):667. doi: 10.3390/jcm10040667. PMID: 33572322; PMCID: PMC7916165. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7916165/