From the Guidelines
It's generally normal for one ovary to be slightly larger than the other, but a significant size difference can indicate several conditions that warrant medical attention, such as ovarian cysts, endometriomas, benign tumors, or rarely, ovarian cancer, and other conditions like polycystic ovary syndrome (PCOS) can also cause ovarian enlargement.
Possible Causes of Ovarian Size Difference
- Ovarian cysts (fluid-filled sacs)
- Endometriomas (tissue growth outside the uterus)
- Benign tumors
- Ovarian cancer (rarely)
- Polycystic ovary syndrome (PCOS)
Importance of Medical Evaluation
If you're experiencing symptoms such as pelvic pain, irregular periods, pain during intercourse, or bloating alongside the size difference, you should consult a healthcare provider. They may recommend ultrasound imaging or other tests to determine the cause. Most ovarian size differences are benign and may not require treatment, but proper evaluation is important to rule out serious conditions and provide appropriate management if needed, as suggested by 1.
Diagnostic Approaches
Ultrasound imaging, particularly transvaginal ultrasound (TVUS), is a useful diagnostic tool for evaluating ovarian morphology and detecting conditions such as PCOS, as noted in 1. The diagnostic criteria for PCOS, including the presence of polycystic ovary morphology (PCOM), are discussed in 1.
Management and Treatment
The management and treatment of ovarian size differences depend on the underlying cause, as discussed in 1. In some cases, no treatment may be necessary, while in others, medical or surgical intervention may be required. A healthcare provider can determine the best course of action based on the individual's specific condition and symptoms.
From the Research
Causes of Ovarian Size Difference
- Polycystic ovary syndrome (PCOS) is a condition that can cause one ovary to be larger than the other, as it is characterized by enlarged ovaries with multiple cysts 2, 3, 4, 5.
- The size difference between the two ovaries can be due to the presence of polycystic ovarian morphology (PCOM) in one ovary, which can lead to a missed diagnosis of PCOS if only one ovary is examined 4.
- Other factors such as ovarian torsion, hematosalpinx, and ovarian hemorrhage can also cause size differences between the ovaries 6.
- Sonographic features such as antral follicle count and ovarian volume can be used to evaluate ovarian size and morphology, but there can be substantial differences between the right and left ovary, even in normal individuals 4.
Sonographic Evaluation
- Ultrasound imaging is a useful tool for evaluating ovarian size and morphology, and can be used to diagnose PCOS and other ovarian conditions 2, 3, 4, 5.
- The use of ultrasound can help identify size differences between the ovaries and detect conditions such as PCOM, ovarian torsion, and hematosalpinx 4, 6.
- Magnetic resonance imaging (MRI) may also be used as an alternative imaging modality for diagnosing PCOM, particularly in adolescence 5.
Clinical Implications
- The diagnosis of PCOS and other ovarian conditions requires a thorough evaluation of both ovaries, as size differences between the ovaries can be a significant factor in diagnosis 4.
- The use of sonographic features such as antral follicle count and ovarian volume can help clinicians diagnose and manage ovarian conditions, but it is essential to consider the potential for size differences between the ovaries 4.