Most ovarian cysts do not make it harder to get pregnant. The most common type, called functional cysts, actually signal that your reproductive system is working normally. But a few specific types of cysts, particularly those linked to endometriosis or polycystic ovary syndrome, can interfere with conception through different mechanisms.
Functional Cysts Are a Sign of Normal Fertility
Every month, a small fluid-filled sac (follicle) grows on your ovary as an egg develops inside it. That follicle produces estrogen and prepares your uterine lining for a potential pregnancy. When the egg matures, the follicle breaks open to release it. If the follicle doesn’t rupture, the fluid stays inside and forms what’s called a follicular cyst. A second type, a corpus luteum cyst, forms after the egg has been released when the empty follicle fills with a small amount of fluid or blood.
Both of these are functional cysts, and they’re extremely common. They typically resolve on their own within one to three menstrual cycles. Because they form as part of the normal ovulation process, having one is actually evidence that the key steps leading to fertility are taking place. They don’t cause infertility and rarely even change your menstrual cycle, though corpus luteum cysts can sometimes cause spotting.
Endometriomas Can Damage Surrounding Tissue
Endometriomas, sometimes called chocolate cysts, are a different story. These form when endometrial tissue grows on or inside the ovary, creating a cyst filled with old blood. Unlike functional cysts, endometriomas can genuinely compromise fertility through several mechanisms.
The fluid inside an endometrioma is rich in inflammatory molecules and reactive oxygen species, essentially chemicals that cause oxidative stress. These substances leak into the surrounding healthy ovarian tissue, triggering a fibrotic response that degrades the ovarian cortex. That matters because the cortex is where your follicles develop. As the tissue around the cyst breaks down, blood supply to nearby follicles decreases, growth factor secretion from surrounding cells drops, and follicular maturation slows. High levels of oxidative stress can also damage blood vessel formation in the ovary, further reducing the blood flow that developing eggs need.
Interestingly, the damage appears to be more structural than inflammatory. Research comparing the fluid around follicles next to endometriomas with fluid from healthy ovaries found no significant differences in inflammatory markers like interleukin levels. The problem seems to be the physical and chemical erosion of the tissue itself rather than widespread inflammation inside the follicle.
PCOS Involves Cysts, but the Real Problem Is Hormonal
Polycystic ovary syndrome is one of the most common causes of fertility difficulty, and the name suggests it’s about cysts. But what shows up on an ultrasound as “cysts” are actually immature follicles, each containing an egg that never received the hormonal signal to fully mature. In a typical cycle, 15 to 20 follicles begin developing each month, but only one becomes dominant, grows to about an inch in diameter, and releases an egg. The rest stop growing and dissolve.
With PCOS, a hormone imbalance prevents that selection process from working properly. Too many follicles grow at the same time, none becomes dominant, and ovulation either doesn’t happen or happens irregularly. The “cysts” visible on ultrasound are really just stalled follicles. They fluctuate over time, don’t cause pelvic pain on their own, and aren’t the root cause of fertility problems. The underlying hormonal disruption is. Many people with PCOS conceive with ovulation-inducing treatments that address that hormonal imbalance directly.
Dermoid Cysts and Cystadenomas Rarely Affect Fertility
Dermoid cysts are benign growths that can contain hair, skin cells, or fatty tissue. Cystadenomas are fluid-filled cysts that develop on the surface of the ovary. Neither type typically interferes with ovulation or egg quality. They fall into the same general category as functional cysts when it comes to fertility: present but not a barrier to conception.
The main concern with these cysts is size. Ovarian cysts larger than five centimeters increase the risk of ovarian torsion, where the ovary twists on its blood supply. This is a medical emergency, but even when surgery is needed, fertility outcomes are reassuring. In a study of 199 women who had surgery for ovarian torsion, live birth rates were similar whether the ovary was untwisted and preserved or surgically removed entirely. Losing one ovary does not appear to significantly reduce your chances of getting pregnant.
Cyst Removal Surgery Can Reduce Ovarian Reserve
If a cyst does need to be surgically removed, the procedure itself can affect your egg supply. A study tracking women before and after cyst removal found that AMH levels, a blood marker that estimates remaining egg supply, dropped significantly within three months of surgery. On average, AMH fell from about 4.5 to 3.2 ng/mL, a roughly 29% decline.
The extent of the drop depends on several factors. Cysts on both ovaries led to a larger decrease (about 2.1 ng/mL) than cysts on just one side (about 1.2 ng/mL). The type of cyst mattered too: endometrioma removal caused the steepest decline in AMH, followed by cystadenomas, with dermoid cysts causing the least damage. The number of times cauterization was used during surgery also played a significant role. Women who had only one cauterization lost about 0.4 ng/mL of AMH, while those with more than four lost nearly 2.0 ng/mL.
This doesn’t mean surgery should be avoided when it’s necessary, but it’s worth discussing the timing and technique with your surgeon, especially if you’re planning to conceive soon. For endometriomas in particular, the decision of whether to operate or proceed directly with fertility treatment is one that depends on cyst size, symptoms, and your overall ovarian reserve.
When Cysts Delay Fertility Treatment
If you’re pursuing IVF or similar treatments, a cyst discovered at the start of a cycle can sometimes delay things. Clinics generally flag simple cysts larger than about 20 mm (roughly 2 cm) as worth evaluating before starting ovarian stimulation. The exact threshold varies by clinic, with some using 15 mm and others 25 mm as their cutoff. These cysts can produce hormones that interfere with the stimulation medications or make it harder to monitor follicle growth on ultrasound.
In most cases, the cyst either resolves on its own by the next cycle or is drained with a simple aspiration procedure. A one-cycle delay is frustrating but doesn’t affect your overall chances of success with treatment.
Pain During Sex Can Be a Practical Barrier
Even when a cyst has no direct biological effect on fertility, it can create an indirect obstacle. Larger cysts sometimes cause deep pelvic pain during intercourse, which can make it difficult to time sex during your fertile window. If you’re experiencing this, it’s worth bringing up with your provider, since the cyst may be manageable with monitoring or a minor procedure, and addressing the pain can remove a real barrier to conception that has nothing to do with your eggs or hormones.