Successful pregnancy rates amongst patients undergoing ovarian tissue cryopreservation for non-malignant indications: A systematic review and meta-analysis

Background: Ovarian tissue cryopreservation (OTC) is a fertility preservation method that has been clinically applied for almost 30 years. Studies specifically evaluating patients presenting with non-malignant indications for OTC and their subsequent pregnancy rates are limited. Objective: To summarise the evidence on the rates of successful pregnancy amongst women who have undergone OTC for non-malignant indications. Methods: A systematic review with meta-analysis (PROSPERO registration CRD42022307925) was conducted to investigate the pregnancy outcomes of patients who have undergone ovarian tissue cryopreservation for nonmalignant indications. Articles published in EMBASE and Ovid MEDLINE before October 2022 were screened for inclusion based on the following criteria: original human studies pertaining to OTC with a defined nonmalignant cohort and pregnancy outcomes. The successful pregnancy rates were pooled with a random-effects model of double-arcsine transformed proportions. Sensitivity analysis involved pooling the results of studies with a low risk of bias after being assessed with NIH tools. Results: The database search retrieved 3,225 results, of which 16 were included in the meta-analysis. The pooled successful pregnancy rate was 23.52 % (16 studies, 95 % CI 6.48 to 44.79 %). When subgroup analysis of study types was performed, the successful pregnancy rate was higher amongst case series (47.02 %, 9 studies, 95 % CI 6.98 to 89.00 %) than cohort studies (14.64 %, 7 studies, 95 % CI 3.59 to 29.78 %). Sensitivity analysis limited to studies at low risk of bias revealed a similar pooled successful pregnancy rate of 23.35 % (12 studies, 95 % CI 2.50 to 51.96 %). Conclusions: Approximately one quarter of women who underwent OTC for non-malignant indications had a successful pregnancy. These findings are clinically important for fertility preservation counselling by providing greater evidence for more informed care.