Are there any conditions in pediatric females where only one ovary develops?

Conditions Where Only One Ovary Develops in Children

Yes, unilateral ovarian absence is a recognized condition in pediatric females, most commonly caused by prenatal torsion or vascular accidents rather than true developmental agenesis, though it can also occur as part of congenital syndromes affecting gonadal development. 1

Primary Etiologies of Single Ovary in Children

Acquired Causes (Most Common)

Torsion or vascular accidents represent the most frequent etiology (52% of cases), occurring during fetal or early postnatal life and resulting in ovarian loss before clinical detection. 1 This mechanism explains why many cases are discovered incidentally during imaging or surgery for other indications, as the event occurred silently in utero or early infancy.

• The affected ovary undergoes necrosis and resorption, leaving no remnant tissue identifiable at surgery 1
• Despite frequent use of the term "ovarian agenesis" in older literature, most cases are actually acquired rather than true developmental absence 1

Congenital/Genetic Causes

Genetic conditions and chromosomal abnormalities can cause true ovarian developmental failure, though these typically affect both ovaries rather than presenting as isolated unilateral absence. 2

• Turner syndrome and other chromosomal abnormalities (trisomy 18,21) reduce the follicular pool and inhibit normal ovarian development, usually bilaterally 3
• NR5A1 gene mutations can present with ovarian insufficiency, sometimes with clitoral hypertrophy at birth or short stature with pubertal delay 2
• Mitochondrial diseases and congenital disorders of glycosylation (CDG) have been associated with primary ovarian insufficiency in pediatric series 2

Associated Congenital Anomalies

When unilateral ovarian absence is identified, clinicians must evaluate for associated genitourinary malformations, as these occur in a significant proportion of cases. 1

• Uterine abnormalities occur in approximately 17% of cases with ovarian absence 1
• Renal abnormalities occur in 22% of cases, and are significantly more likely when uterine abnormalities are also present (p < 0.005) 1
• This association reflects the shared embryological origin of the Müllerian and mesonephric systems 1

Clinical Presentation and Diagnosis

Common Presentations

Most cases of unilateral ovarian absence are discovered incidentally or present with non-specific symptoms rather than reproductive dysfunction. 1

• Abdominal or pelvic pain (30% of cases) 1
• Infertility or subfertility concerns (19% of cases) 1
• Incidental finding during imaging or surgery for other indications (28% had no pre-operative suspicion) 1

Diagnostic Approach

Pre-operative imaging frequently fails to identify ovarian absence, with 28% of cases showing no abnormality on ultrasound or other imaging modalities. 1 This occurs because:

• The contralateral ovary may appear normal and be mistakenly identified as both ovaries on different views
• Small ovarian remnants or streak gonads may be below imaging resolution
• Operator experience and imaging quality significantly affect detection rates 1

Diagnostic laparoscopy remains the gold standard for confirming ovarian absence and should be considered when clinical suspicion exists, as it allows simultaneous assessment of uterine anatomy, the contralateral ovary, and other pelvic structures. 1

Fertility Implications and Prognosis

Women with a single ovary (whether congenital or acquired) have normal potential to conceive naturally or through assisted reproduction, but should expect a shorter reproductive lifespan compared to women with two ovaries. 4

• The incidence of having a single ovary reaches up to 17% in women with severe tubal disease requiring IVF, indicating it is relatively common in fertility populations 5
• Fertility is likely minimally or not affected in women with unilateral ovarian absence, as the remaining ovary compensates 1
• The shortened reproductive period reflects accelerated depletion of the finite follicular pool from a single ovary 4

Iatrogenic Single Ovary

Unilateral oophorectomy in childhood cancer survivors results in similar fertility outcomes to congenital single ovary, with normal conception potential but earlier onset of ovarian insufficiency. 4

• Survivors should receive counseling about the risk of earlier menopause 4
• Those with single ovary after cancer treatment may have additional fertility risks from chemotherapy or radiation effects on the remaining ovary 4

Critical Clinical Pitfalls

Do not assume normal ovarian anatomy based on imaging alone—approximately 28% of cases with surgically-confirmed ovarian absence had normal pre-operative imaging. 1

Always evaluate renal anatomy when unilateral ovarian absence is identified, particularly if uterine abnormalities are present, as renal anomalies occur in 22% of cases. 1

Distinguish between true bilateral ovarian insufficiency (which requires hormone replacement) and unilateral absence (which typically has normal endocrine function from the remaining ovary). 4, 1 The remaining ovary in unilateral absence cases maintains normal follicular development and hormone production throughout childhood. 6, 3