From the Research
Bilateral ovarian follicles in a 20-month-old baby are not typically considered a normal finding on ultrasound, and their presence warrants further evaluation by a pediatric endocrinologist or gynecologist. In female infants and young toddlers, the ovaries should be relatively quiescent with minimal follicular activity until closer to puberty. The presence of multiple follicles in a child this young could potentially indicate premature thelarche (early breast development), precocious puberty, or other hormonal abnormalities.
Some studies have investigated ovarian development in infants, including a 2021 study that characterized ovarian growth trajectories and ovarian follicle development during the first 9 months of life in a large longitudinal cohort of healthy girls 1. However, the most recent and highest quality study, published in 2025, provides normative data of infant ovarian and uterine morphology directly implementable to a clinical setting, which can be used to assess the normalcy of bilateral ovarian follicles in a 20-month-old baby 2.
While isolated small follicles (1-2 mm) might occasionally be seen, multiple or larger follicles suggest hormonal stimulation that is not age-appropriate and should prompt medical investigation to determine the cause and appropriate management. The evaluation would typically include assessment of growth parameters, physical examination for signs of puberty, and possibly hormonal blood tests to measure estradiol, gonadotropins (FSH, LH), and other relevant hormones.
In some cases, the presence of bilateral ovarian follicles might be associated with conditions like McCune-Albright syndrome or exposure to exogenous hormones. Therefore, a thorough medical evaluation is necessary to determine the underlying cause of this finding and provide appropriate management to prevent potential long-term consequences on the child's health and fertility.
Key points to consider in the evaluation of bilateral ovarian follicles in a 20-month-old baby include:
- Assessment of growth parameters and physical examination for signs of puberty
- Hormonal blood tests to measure estradiol, gonadotropins (FSH, LH), and other relevant hormones
- Consideration of potential underlying conditions, such as McCune-Albright syndrome or exposure to exogenous hormones
- Referral to a pediatric endocrinologist or gynecologist for further evaluation and management.