Ovarian cysts are extremely common in ovulating women—though you might not know it, most women produce at least one ovarian cyst every month (that’s the follicle your egg comes from!). While the majority of cysts are harmless or even helpful, some ovarian cysts affect fertility, by way of the illnesses that cause the cysts.
What are ovarian cysts?
“Cyst” is the generic name for a fluid-filled sac or cavity that can form in many places throughout the human body. Not all ovarian cysts affect fertility, by the way. In fact, functional cysts sometimes form as a byproduct of the regular process of ovulation. A brief ovulation overview: each month (usually), an egg grows in an ovarian follicle, matures, and breaks out of the follicle before traveling down the fallopian tubes toward the uterus.
Two types of cysts are common byproducts of ovulation:
- Follicular cysts form when, instead of breaking open to release the egg, the follicle stays intact and the cyst continues to grow.
- Corpus luteum cysts, or luteal cysts, sometimes form after ovulation. Normally, once the egg has broken free, the follicle shrinks into a mass of cells known as the corpus luteum, which produces hormones to prepare for the next cycle. Luteal cysts form when, instead of shrinking, the follicle reseals itself and fluid builds up inside.
Both of these cysts are typically harmless and disappear within 1–3 months without treatment. And for pregnant women, corpus luteum cysts are actually super important: they produce progesterone, a hormone that’s essential for the first 8–10 weeks of pregnancy.
Which ovarian cysts affect fertility, and how?
There are a few types of cysts associated with lower fertility. How do ovarian cysts affect fertility? In actuality, it’s not these cysts themselves that make it harder to get pregnant—they are simply symptoms of larger illnesses that may compromise fertility.
Endometriosis is one example of an illness that can cause ovarian cysts that affects fertility. Endometriosis occurs when endometrial tissue—the lining of the uterus—begins to grow in other places, like on the outside of the uterus or the fallopian tubes. One result of endometriosis is ovarian cysts known as “endometriomas,” formed when this tissue grows in the ovaries. Endometriomas can range in size from less than an inch to over 6 inches, and are often filled with dark blood.
While doctors aren’t 100% sure how these ovarian cysts affect fertility, they do know that endometriosis is closely tied to infertility; some studies demonstrate that women with even mild cases of endometriosis have only a 2–4% chance of getting pregnant each month (compared to the 15–20% chance healthy women have). Dr. Iris Orbuch, OB/GYN and endometriosis specialist, estimates that “40% of unexplained infertility is due to endometriosis,” which both “decreases a woman’s ovarian reserve [and] decreases fertility by either an anatomical distortion or via inflammation.”
Learn more about endometriosis.
Secondly, polycystic ovary syndrome (PCOS), a hormone imbalance that causes many tiny ovarian cysts, affects fertility by a higher rate than almost any other condition (besides age). In PCOS, the eggs that begin to develop during the ovulation cycle never mature enough to prompt ovulation, so none of them are released from the ovary. The immature follicles, each containing an immature egg, then cause the ovary to become “polycystic,” filled with these tiny cysts.
The chronic lack of ovulation alters the levels of hormones that play an important role in the ovulation process, and PCOS is often associated with higher levels of male hormones known as “androgens.” It’s not the ovarian cysts themselves that affect fertility in cases of PCOS—it’s the fact that women with PCOS don’t ovulate, and ovulation is essential for getting pregnant naturally.
Can ovarian cysts have other side effects?
While it’s not typical for ovarian cysts to affect fertility, larger or multiple cysts can have other side effects or symptoms, such as bloating, needing to urinate more often, pelvic pressure or pain, or abnormal vaginal bleeding. If your cyst(s) doesn’t go away on its own after a few months, continues to grow, or causes you pain, your doctor might recommend surgery to remove it. With larger ovarian cysts, there is the concern for a rare condition of twisting of the ovary, called ovarian torsion, which—if not corrected promptly with surgery—can lead to loss of an ovary. Alternative treatments for benign cysts include hormonal birth control—such as the pill, vaginal ring, shot, or patch—which prevent ovulation and lower your chances of getting more cysts. Malignant (cancerous) cysts are very rare in young women.
Can treatment for ovarian cysts affect fertility?
That depends on the treatment. Hormonal birth control doesn’t have a long-term effect on fertility (learn more about birth control and fertility). Surgery almost invariably damages some healthy eggs, and complications can (rarely, but sometimes) mean doctors need to remove an entire ovary. Both situations result in a lower egg count, which is one factor in fertility.
Should women with ovarian cysts freeze their eggs?
While not all ovarian cysts affect fertility by way of reproductive illness, there are cases in which a woman may want to consider egg freezing to preserve fertility.
Women with endometriosis who aren’t yet ready to get pregnant are excellent candidates for egg freezing. During endometriosis, the abnormally growing endometrial tissue can cause inflammation, scarring, cysts, and organ damage, including damage to the ovary. And if the ovary is damaged, it can mean impaired egg production or ovulation—or none at all.
Additionally, while surgical treatment of endometriosis offers long-term pain relief, studies show that it may actually reduce ovarian reserve (and therefore fertility) by inadvertently removing healthy ovarian tissue or cutting off blood supply to the ovary. Freezing eggs before endometriosis progresses too far is the best way to preserve fertility options for later in life.
And surgical treatment of other ovarian cysts affects fertility by damaging healthy eggs. Women who have had ovarian cysts surgically removed will typically have a lower egg count. For that reason, women who are considering surgery for ovarian cysts should also consider freezing their eggs—prior to the surgery, if possible, or after the removal of the cyst, if the size or location of the cyst will make egg freezing too risky or complicated.
Learn more about how ovarian cysts affect fertility—and how egg freezing can help: