Discovering one ovary appears larger than the other can be concerning. While sometimes indicating a serious condition, it often results from normal physiological processes or benign issues. This article explores common reasons for ovarian enlargement, providing clarity on this gynecological observation.
Understanding Normal Ovary Size
Ovaries are small, oval-shaped organs located on either side of the uterus. Their size varies significantly with age and hormonal status. During reproductive years, ovaries average 40 x 30 x 20 mm, with a volume between 4 and 6 mL. After menopause, ovarian size naturally decreases, averaging 2.0 cm in length, 1.5 cm in height, and 1.0 cm in width, with a mean volume of about 2.2 mL. It is normal for one ovary to be slightly larger than the other, and size can fluctuate throughout the menstrual cycle.
Common Reasons for Ovary Enlargement
A frequent reason for temporary ovarian enlargement relates to the normal menstrual cycle. During ovulation, a follicle grows and swells, potentially reaching 18-27 mm before releasing an egg. After ovulation, this follicle transforms into a corpus luteum, which can also temporarily enlarge the ovary. These “functional cysts,” including follicular cysts (when a follicle doesn’t rupture) or corpus luteum cysts (when the corpus luteum fills with fluid), usually resolve on their own within a few months.
Beyond these physiological changes, other benign ovarian cysts can cause enlargement. These include dermoid cysts, which contain various tissues like hair or skin, and endometriomas, formed from endometrial-like tissue outside the uterus, often associated with endometriosis. These benign cysts vary in size and may cause one ovary to appear larger.
Polycystic Ovary Syndrome (PCOS) is another common condition leading to enlarged ovaries. In PCOS, hormonal imbalances cause multiple small follicles to develop but not mature or release eggs regularly. This results in larger ovaries containing many small cysts, affecting one or both ovaries, and is often associated with irregular periods.
Infections or inflammation, such as Pelvic Inflammatory Disease (PID), can also cause ovarian enlargement. PID, an infection of the female reproductive organs, can lead to tubo-ovarian abscesses, which are pockets of pus involving the ovary and fallopian tube. Additionally, ovarian edema, a rare condition where fluid accumulates within ovarian tissue, can cause unilateral enlargement, sometimes due to partial ovarian torsion.
Less commonly, an ectopic pregnancy can present with an enlarged ovary. This occurs when a fertilized egg implants outside the uterus, sometimes involving the ovary itself, causing swelling and pain. Benign ovarian tumors, which are non-cancerous growths, can also contribute to an enlarged ovary. While most enlarged ovaries are benign, ovarian cancer, though uncommon, remains a possibility requiring investigation.
When to Seek Medical Advice
While many instances of an enlarged ovary are harmless, certain symptoms warrant a consultation with a healthcare professional. Persistent pelvic pain or discomfort, especially if severe or worsening, should prompt medical attention. This pain might be localized to one side if only one ovary is affected.
Other concerning symptoms include:
Unexplained abdominal bloating or a feeling of fullness.
Changes in bowel habits, such as constipation or increased urinary urgency.
Abnormal vaginal discharge.
Irregular or unusually heavy menstrual bleeding.
Pain during sexual intercourse.
Unexpected weight changes (gain or loss).
If an enlarged ovary is discovered incidentally during an imaging scan, a medical evaluation is still recommended to determine its cause and monitor its progression.
Diagnosis and Management Approaches
When an enlarged ovary is suspected, healthcare providers begin with a physical exam and symptom review. A pelvic ultrasound is often the primary diagnostic tool, imaging the reproductive organs to determine the enlargement’s size, characteristics, and nature (e.g., fluid-filled cyst or solid mass). Blood tests, like a CA-125 level, may also be used, especially if malignancy is a concern, though this marker can be elevated in benign conditions.
Management depends on the underlying cause. For many physiological cysts, watchful waiting is recommended, as they often resolve on their own. For conditions like Polycystic Ovary Syndrome (PCOS), management may involve medications. In cases of large or symptomatic cysts or suspected malignancy, surgical intervention may be necessary. Healthcare providers tailor a management plan based on the diagnosis, aiming to alleviate symptoms and address potential health risks.