What is an ovarian cyst?

What Is an Ovarian Cyst and Can it Affect Infertility?

9 min read

Worried about a cyst? Whether it’s Dr. Google or your actual doctor that’s put it on your radar, the term “cyst” could be causing a bit of stress. The good news: ovarian cysts are common among reproductive-aged females, and most are a totally normal part of ovulation. To help you figure out where you stand, let’s break down what an ovarian cyst is, how it’s treated and what it means for fertility.

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What is a cyst?

A cyst—in its most basic definition—is a sac filled with fluid or tissue. The characteristics of the cyst (including the type and size) will determine if any medical treatment is needed. When cysts are small, they often don’t cause any symptoms, don’t impact your hormones and resolve on their own. Time is the greatest medicine in many circumstances, and observation is a common approach. 

What are the different types of ovarian cysts?

There are two main types of ovarian cysts: ones that occur because of normal ovulation (functional cysts), and ones that are pathological or abnormal.

Functional cysts: A common part of the ovulation process, benign in nature and self-resolving. 

  • Follicular cysts
  • Hemorrhagic cysts 
  • Corpus luteum cysts

Pathological cysts: Caused by abnormal cell growth not related to the menstrual cycle. 

  • Dermoid cysts
  • Endometrial ovarian cysts 
  • Ovarian tumours

What are functional cysts?

Functional cysts are cysts created during the menstrual cycle because of ovulation. They are considered normal and are typically not cause for concern. Functional cysts are usually classified into three categories: follicular, hemorrhagic and corpus luteum cysts.

Follicular cysts: The ovaries naturally create cysts (in this case, growing follicles) during each menstrual cycle because of ovulation. In the first phase of the cycle a dominant follicle will grow before rupturing to release the egg and this growing follicle can be classified as a follicular cyst. 

Corpus luteum cysts: After the egg is released, the remaining shell of follicular cells forms the corpus luteum, a structure that secretes progesterone. Normally, it breaks down at the end of the menstrual cycle if you’re not pregnant, but on rare occasions it can fill with fluid and persist longer than the two-week luteal phase. If this happens and it grows, it’s called a corpus luteum cyst.

Hemorrhagic cysts: After ovulation, the corpus luteum is formed and sometimes the surrounding cells that have access to the blood supply can bleed into it, creating a hemorrhagic cyst.

What Is a Normal Period? →

What are pathological cysts?

Pathological cysts are cysts that happen outside of what would be expected during a menstrual cycle. This is considered abnormal cell growth and should be monitored and assessed for treatment. Pathological cysts include dermoid cysts, endometriomas and ovarian tumours.

What are dermoid cysts?

Dermoid cysts are slow-growing tumours made up of different types of body tissues (like hair, skin and teeth). Tumour in this case does not mean cancer—it means a mass of tissue that forms abnormally. They rarely cause complications, unless they grow to be quite big (greater than five centimetres). In these cases, the size can cause abdominal pressure or pain. In rare occasions the large dermoid cysts can cause the ovary to twist and stop the blood flow, essentially strangling itself. This is referred to as ovarian torsion and it’s considered a medical emergency that requires surgery to untwist and save the ovary and restore blood flow.

What are endometrial ovarian cysts?

Endometrial cysts are one of the main manifestations of endometriosis, a condition where endometrial tissue is present outside of the uterus. Also called chocolate cysts or endometriomas, endometrial ovarian cysts occur when a cyst is made of endometrial (uterine lining) tissue, and has a dark, dense appearance. Being made of endometrial tissue, this type of cyst responds to hormones just like the uterus; it can bleed internally to a certain degree.

Endometrial cysts can be seen using ultrasound, but they don’t always show the whole picture—endometriomas and their sticky adhesions are sneaky and can lurk throughout the pelvic and abdominal cavities. The bowels can also get in the way of seeing lesions, so if your doctor suspects endometriosis they may ask you to do a bowel cleanse before your ultrasound, or they might send you for an MRI. Although symptoms and imaging are generally enough to be diagnosed with endometriosis, the gold standard is through a laparoscopic surgery to remove the tissue and to analyse it under a microscope.

Learn More About Endometriosis and How It Affects Fertility →

What are ovarian tumours?

An ovarian tumour presents as a cyst and it can be completely benign (like a dermoid cyst), malignant (ovarian cancer) or borderline (currently benign but it has the potential to become malignant in the future). To determine whether a tumour is cancerous or not, doctors can look for some symptoms and signs (for example, prolonged fevers or weight loss, or abnormal or alarming ultrasound findings) and when there’s cause for concern, a diagnosis can be confirmed  by operating to remove the tissue and having it examined by a pathologist in the lab.

What are the symptoms of an ovarian cyst?

Not all ovarian cysts cause symptoms, but some common indicators include abdominal bloating or irregular periods. While most ovarian cysts shrink and disappear on their own, others are at a greater risk for growing, which can lead to more obvious symptoms, like pain.

What does ovarian cyst pain feel like?

About seven percent of women will experience pain because of a cyst during their lifetime. This could be a dull and constant ache or pain in specific circumstances, like during bowel movements or with sex. In more extreme forms, ovarian cyst pain can be sharp and severe, especially if a cyst ruptures or is causing ovarian torsion—the latter of which also comes with nausea and vomiting. Any pain should be assessed by your doctor, but sharp, extreme pain means a trip to the emergency room, for immediate medical attention.

What causes ovarian cysts?

Functional cysts occur when the ovaries respond to hormones (including follicular stimulating hormone and luteinizing hormone) released from the pituitary—anything that might impact the delicate balance of hormones can impact the formation and resolution of cysts. 

Other cysts (like dermoid cysts, endometriomas, and ovarian cancer) often don’t have a specific cause. There are certain things that might place someone at a higher risk of developing them, but this isn’t always a trusty indication. For example, there are scenarios that we know can increase the risk of ovarian cancer (these include a family history or having a specific genetic marker, like BRCA). There are also scenarios that we know lower the risk of ovarian cancer (like if you’ve had a full term pregnancy, if you’ve breastfed, or if you were on hormonal birth control). 

Are ovarian cysts cancerous?

Almost all ovarian cysts are benign—non-cancerous—especially during the reproductive years. Most cysts are formed from normal ovulation and malignancy of an ovarian cyst is rare in pre-menopausal women.

There are some features of an ovarian cyst that might raise more concerns like increasing in size in a short time span, having a solid component within the cyst, noticing thickened or irregular cyst walls or having increased blood flow.

If you are experiencing severe pelvic or lower abdominal pain, your doctor will likely order a transvaginal or pelvic ultrasound as part of your work-up to find the source of the pain. Even if you don’t have any symptoms, if a cyst is seen with ultrasound, your doctor will likely monitor it, sending you for a follow-up ultrasound in a few weeks or months to see if the cyst has disappeared, grown or changed in any way. Although there are some ultrasound features that can help differentiate benign from malignant cysts, the only way to know the nature of a cyst for sure is to remove it and analyze it. In general, if your doctor is concerned about your ovarian cyst, they will likely recommend surgery to remove it as a form of diagnosis and treatment.

What Are Possible Infertility Diagnoses? →

How are ovarian cysts treated? 

In general, functional cysts are considered normal, are common and will resolve on their own with time. They can cause short-term symptoms like pelvic pain, or a delayed period, but in most cases this will sort itself out without any medical or surgical intervention.

Dermoid cysts don’t resolve on their own—they will either remain stable in size or grow, but they won’t shrink. If seen with ultrasound imaging, your doctor will likely monitor and check to see how fast it’s growing, but they likely won’t recommend surgery unless the tumour is at least five centimetres in diameter. At this point the risk of ovarian torsion is higher, and the chance of it being ovarian cancer (though still low) must be considered. 

Since endometriosis is a chronic condition that causes lesions to continue growing and spreading, endometrial ovarian cysts can be difficult to treat. In some cases surgery may be warranted, but, surgery itself, especially when it involves removing tissue in or on the ovary can reduce ovarian egg reserves even further—surgery is often not advised if you are over the age of 35 and undergoing infertility treatment. Also, even if surgery is performed and lesions are removed, without any additional support or treatment, these types of cysts and their sticky adhesions tend to return. 

When it comes to endometriosis, it’s important to work with your doctor to create a treatment plan focused on your goals, which can be reducing pelvic pain or trying to conceive. Traditional treatment options include surgical or medical intervention (hormonal suppression). But, there’s also an opportunity to consult a naturopathic doctor or functional medicine doctor who can provide a supporting treatment plan to slow and prevent the growth of lesions with dietary and lifestyle changes and with specific antioxidant, anti-inflammatory and estrogen-modulating supplements for endometriosis.

Do ovarian cysts affect your fertility?

Functional cysts are not thought to impact fertility, since they are a normal part of menstruation and often resolve on their own. In fact, when doctors spot these on ultrasounds, they often don’t even mention it to patients because there are no negative implications. Pathological cysts are a bit more complicated.

Dermoid cysts and ovarian tumours on their own don’t impact your fertility, but the treatment for them might. If you require surgery, that may lead to scar tissue in your pelvis or a lower ovarian reserve because of the operation on the ovary. And if the tumour is due to ovarian cancer, you may require surgery to remove your ovaries or chemotherapy treatment which can have negative consequences for your fertility. In these rare situations, getting an urgent consult with a fertility doctor is highly recommended and your fertility options might include freezing your eggs prior to having any cancer treatment initiated. 

When cysts are related to endometriosis, they can potentially impact fertility. Studies suggest that endometriosis can negatively impact egg maturation and quality and affect the uterine environment, making it harder for an embryo to implant. And we do know that endometriomas can impact egg reserves, that adhesions around the fallopian tubes might prevent egg and sperm from meeting up, and that endometriosis is strongly associated with inflammation and oxidative stress. Having endometriosis—even severe endometriosis—doesn’t necessarily mean you’ll have a hard time conceiving, but, it’s hard to predict these outcomes, so speaking to your doctor about your fertility goals is key.

When should I see my doctor?

If you’re feeling any severe lower abdominal pain it warrants a visit to your doctor, especially if you’re also dealing with nausea, vomiting, light-headedness or fever. If an ovarian cyst is detected, make sure you speak with your doctor to better understand both the type of cyst you have and the plan moving forward—even if it’s just to wait and see.