Endometriosis and Its Effect on Fertility and Pregnancy

Been wondering about endometriosis and its effect on fertility? Dr. Naz explains what endometriosis is, how to get diagnosed, treatments, and how it may impact pregnancy.

By Dr. Nazaneen Homaifar

1. To get started, what is endometriosis?

Simply put, endometriosis is a condition in which tissue similar to uterine lining (or endometrium) implants, or abnormally spreads, along the pelvis or on other organs in the abdomen. It affects about one in ten reproductive-age women globally. There is a strong genetic component, as well: patients with an affected first-degree relative have nearly a seven to ten fold increased risk of developing endometriosis. 

The exact cause of endometriosis is still unknown. The leading theory suggests that during menstruation (or a period), some of the uterine lining tissue (or endometrial tissue) flows back up through the fallopian tubes into the abdomen and then implants and grows—almost like a “reverse menstruation” (endometrial tissue flows out of the vagina and on a pad or tampon, but some flows back into the pelvis). This tissue is estrogen-dependent, something to remember when we go back to discussing treatment options. Other theories suggest that endometrial tissue travels and implants the way cancer cells spread through blood or lymphatic channels. 

Implants of endometriosis can form along the ovaries, fallopian tubes, appendix, rectum and bowel (large intestines), pelvic wall, muscles, and sometimes even in the upper abdomen, like the diaphragm. Implants can also develop from direct transplantation as well; for example, in the abdominal wall after a cesarean section. 

Endometriosis appears in three different forms in the body. The extent of endometriosis (how mild or strong symptoms can be and how it affects the body) are dependent on these features. 

• Superficial peritoneal implants: Small implants less than five millimeters in size along the peritoneum, or the lining of the abdomen. These implants are usually considered the most minimal form of endometriosis 
• Endometriomas: Ovarian cysts that develop from endometrial tissue implanting in the ovary. They are also referred to as “chocolate cysts” because of the dark brownish fluid from the ovary bleeding and scarring over itself.
• Deep infiltrative endometriosis: Invasion of endometriosis in organs within or outside the pelvis usually causing significant scarring, sometimes referred to as a “frozen pelvis.”

You may have also heard of adenomyosis. Adenomyosis is like a sister condition to endometriosis and involves implants of the endometrial lining in the middle layer of the uterus, or the myometrium. Sometimes the implants can be mistaken for fibroids if they’re larger and discrete. The implants give the uterus a bulky and often characteristic globe-shaped appearance on pelvic ultrasound. 

2. What are the symptoms of endometriosis?

Some women with endometriosis may not have any symptoms at all. However, for those affected, some of the most common symptoms of endometriosis include: 

• Pelvic pain
• Pain before and during periods 
• Pain during sex 
• Infertility
• Fatigue 
• Painful urination during periods 
• Painful bowel movements during periods 
• Other gastrointestinal upsets such as diarrhea, constipation, and nausea

Although exactly how endometriosis causes pain is not fully understood, it is thought to be attributed to its inflammatory effects.

People with adenomyosis often have very painful, heavy periods.

3. How is endometriosis diagnosed?

Although endometriosis affects about ten percent of reproductive-aged women, many studies report a long delay between the onset of symptoms like pelvic pain and a diagnosis of endometriosis. In fact, a patient may see seven to eight doctors before a diagnosis of endometriosis. A combination of five studies involving about 1,190 women found a difference of 8.6 years between the age of symptom onset (pelvic pain symptoms) and age at diagnosis. 

Traditionally, medical literature stated that for a diagnosis of endometriosis, surgeons needed to visualize endometriosis lesions at the time of surgery, most often with a minimally invasive approach called laparoscopy, and with tissue diagnosis on pathology. However, it’s not practical to take everyone to surgery in order to provide an endometriosis diagnosis. 

Instead, a combination of symptoms, signs, and imaging findings can be used to make a presumptive nonsurgical diagnosis of endometriosis. This usually includes a physical examination by a gynecologist, a series of questions to better understand the symptoms, and potentially, a pelvic ultrasound to evaluate the uterus and ovaries. An ultrasound will not show superficial peritoneal implants, but it can highlight endometriomas (they have a very characteristic appearance) and sometimes even evidence of deep infiltrative endometriosis.

4. What are the treatments for endometriosis?

Treatments for endometriosis can be categorized as the following: medication management, surgical management, and management with alternative and complementary approaches. The goals of treatment are often centered around: 

• Alleviating symptoms of endometriosis
• Preventing further growth of implants or endometriomas
• Preventing recurrence of endometriomas
• Preserving or restoring fertility

Treatment decisions should be individualized to a person’s symptoms and severity, extent of endometriosis, reproductive desires, and age. 

Medications are used in endometriosis to control symptoms of pelvic pain and menses. Medical management involves hormonal and non-hormonal medications. For pain relief, doctors often rely on nonsteroidal anti-inflammatory drugs (for example, ibuprofen), antidepressants, or medications that treat neuropathic (nerve-related) pain, like gabapentin. Hormonal contraception that contains estrogen and progestin, or progestin-only, are used to suppress the ovaries from functioning, thereby reducing the growth of endometrial tissue. Hormonal options include birth control pills, Depo-Provera injections, the progesterone-only implant, and progesterone intrauterine devices. There are also newer medications on the market specifically designed for people with endometriosis, including elagolix, a gonadotropin-releasing hormone (GnRH) receptor antagonist. 

Surgical management is indicated if a person’s symptoms of endometriosis do not respond to medication management. If there is concern for extensive endometriosis, the surgery should be performed by a gynecologist who is trained to operate on difficult endometriosis cases. If you’re seeing a reproductive endocrinologist and infertility (REI) doctor because you’re having difficulty getting pregnant, you should talk to them about the appropriateness of a surgical treatment. Surgery may include removal of an endometrioma, burning or cutting out endometrial implants, or performing a more extensive surgery, such as removing deep infiltrative endometriosis and organs like the uterus, cervix, and ovaries. 

Alternative and complementary approaches to medical and surgical management include use of acupuncture, biofeedback, pelvic physical therapy, behavioral modifications, and lifestyle changes. Pelvic physical therapy includes internal treatment to stretch pelvic floor muscles, release myofascial pain, biofeedback and trigger point release. One study found that in those with myofascial chronic pelvic pain, 63% (of 146 women) reported significant pain improvement after at least 6 sessions. The evidence to support the effectiveness of acupuncture for pain in endometriosis is limited, mainly because the studies haven’t been robust. In one study, acupuncture significantly reduced pain in cases of severe painful menses. In terms of lifestyle, one study suggested that diets containing high levels of long-chain omega 3 fatty acids (think fatty fish, chia seeds, walnuts, brussel sprouts) decreased the risk of endometriosis, however the quality of evidence is not the best. Like many studies on alternative and complementary approaches, the literature is sparse or the studies are not always rigorously designed, which makes drawing conclusions on the data more difficult. 

5. Does one have endometriosis their whole life?

Yes, but the symptoms tend to improve after menopause when the estrogen that stimulates endometrial implants is no longer active. That being said, depending on the extent of endometriosis, some women may have some symptoms after menopause. 

The American Society for Reproductive Medicine Practice Committee statement concludes, "endometriosis should be viewed as a chronic disease that requires a lifelong management plan with the goal of maximizing the use of medical treatment and avoiding repeated surgical procedures."

6. How does endometriosis affect trying to get pregnant?

Studies suggest that 25-50% of infertile women have endometriosis and that 30-50% of women with endometriosis are infertile. In mild to moderate cases, the infertility may be temporary. In these cases, surgery to remove adhesions, cysts, and scar tissue can restore fertility. In other cases—a very small percentage—women may remain infertile.

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We’re not completely sure of all the ways endometriosis can affect fertility. We think that scar tissue from endometriosis can block the fallopian tubes or impair the release of the egg from the ovary. It may also change the environment in the pelvis and make it difficult for a fertilized egg to implant in the uterine lining. 

7. How does endometriosis affect pregnancy?

Some good news on this front: endometriosis symptoms tend to disappear or improve in pregnancy. However, there are some associated risks to be aware of: in multiple studies, endometriosis has been found to increase the risk of preterm birth, hypertensive disorders in pregnancy (like preeclampsia), and cesarean delivery. Other studies have also found an association with increased risk of miscarriage, placenta previa (the placenta lies over the cervix in pregnancy and necessitates cesarean delivery), and later pregnancy complications. Keep in mind that we don’t fully understand why this is the case and if there are other factors we should consider (like the fact that many of these people may have undergone IVF and IVF in itself increases the risk of some of these conditions). 

In most cases, a history of endometriosis does not mean that patients need to see a high-risk OB doctor during pregnancy, but it’s an important point to discuss with your health care provider during the preconception visit and during the initial prenatal encounter. 

8. Anything else about endometriosis?

There is a lot of important research being done in endometriosis to better understand how it works, what other implications it has on someone’s long term health, and the multimodal approaches that we can use to treat the sometimes debilitating symptoms of endometriosis. If you’re worried that you may have endometriosis, talk to your OBGYN. 

If you have a long standing history of the symptoms or a diagnosis of endometriosis and have found it difficult to navigate the healthcare system, consider searching for a dedicated Center for Endometriosis. These centers (whether in academic medicine or in the private setting) are focused on providing multiple resources to help people with endometriosis, including trained gynecologic surgeons, fertility specialists (REI), nurse practitioners, pelvic floor therapists, and sometimes, patient navigators. For more information on endometriosis, check out information on the following websites:

• Endometriosis.org: A nonprofit website dedicated to information about endometriosis and treatment.
• American College of Obstetricians and Gynecologists: Frequently asked questions about endometriosis.
• American Society for Reproductive Medicine: Provides free materials on reproductive health issues for patients.
• The Endometriosis Association: An independent, nonprofit, self-help organization of women with endometriosis, clinicians, and others interested in the disease.

Have, or suspect you have, endometriosis and thinking about getting pregnant? Now is a great time to check in with your provider for a pre-pregnancy checkup. This guide will spell out how to prepare and what to expect at that visit.