Pediatric ovarian volumes measured at ultrasound after contralateral unilateral oophorectomy

Background: Changes that occur in the remaining ovary after contralateral oophorectomy are not well described.

Objective: To determine average ovarian volume in pediatric patients after contralateral oophorectomy compared to age-matched controls with two normal ovaries.

Materials and methods: We performed a retrospective review of ultrasound examinations and electronic medical records of patients ages 0-18 years who had unilateral oophorectomy from 2000 to 2017 (n=64). We used 384 consecutive normal age-matched ovaries for comparison, analyzing mean ovarian volumes.

Results: Higher mean ovarian volume (mL) was observed in patients who had oophorectomy compared to controls in the first decade of life (P<0.003) and second decade of life (P<0.0003). Higher mean ovarian volume was seen in both premenarchal and menstruating patients with prior oophorectomy when compared to controls (P<0.05 and P<0.0001, respectively). When comparing volume during menstrual cycle, we saw higher mean ovarian volumes in the oophorectomy group compared to the control group for the follicular (P<0.0001), pre-ovulatory (P=0.0005) and luteal phases (P<0.0003). We provide an updated reference of normal ovarian volumes for pediatric patients, with values similar to those already reported in the literature.

Conclusion: Ovarian volume is higher in pediatric patients with one normal ovary following contralateral oophorectomy. The provided normative volumes can be used in evaluating these patients.