In vitro maturation rates in young premenarche patients.

OBJECTIVE:To evaluate in vitro maturation (IVM) efficacy and oocyte retrieval rates after ovarian tissue cryopreservation in young premenarche girls facing chemo- and radiotherapy. DESIGN:A retrospective cohort study. SETTING:University-affiliated tertiary medical center. PATIENT(S):A total of 84 chemotherapy-naïve patients ages 0-18 years referred for fertility preservation between 2004 and 2017: 33 premenarche and 51 postmenarche patients. INTERVENTION(S):None. MAIN OUTCOME MEASURE(S):IVM in the pre- and postmenarche groups and in the subgroups of very young (up to age 5 years) and older (5-10 years) premenarche girls. RESULTS:The number of oocytes retrieved did not significantly differ between the postmenarche and premenarche groups (10.8 ± 8.5 and 8.1 ± 6.8, respectively). However, the overall IVM rate was significantly higher in the postmenarche group (28.2% vs. 15.5%, respectively; odds ratio = 0.47). A separate analysis for patients up to 5 years of age demonstrated significantly lower oocyte yield compared with the older (5-10 years) premenarche girls (4.7 ± 5.2 vs.10.3 ± 7.0 oocytes, respectively) and much lower IVM rates (4.9% and 18.2%, respectively). Correlation of age with number of retrieved and matured oocytes showed a positive significant correlation (r = 0.45 and r = 0.64, respectively). CONCLUSIONS:IVM performed after ovarian tissue cryopreservation in premenarche girls and specifically in very young girls (4 years and younger) yields substantially decreased maturation rates compared with postmenarche patients, raising a question as to the utility of current IVM technique in this age group. Further studies are required to assess modification of the IVM technique for young girls.