Time from referral to ovarian tissue cryopreservation in a cohort of Danish women

Abstract

Introduction: Young women with a cancer diagnosis often have very little time to decide whether or not to commence fertility-preserving strategies before initiating potentially sterilizing cancer treatment. Minimizing the interval from opting for fertility preservation to completion of the procedure will reduce the potential risk of delaying cancer treatment. In the current study, we have evaluated the period of time from referral to ovarian tissue cryopreservation (OTC) to actual freezing of the tissue in a cohort of Danish women.

Material and methods: The study population comprised 277 consecutive patients with both malignant and nonmalignant diseases referred for OTC from four centers in the Danish network. Statistical analysis was conducted to analyze the impact of age, diagnosis, and referring center on the time from OTC-referral to OTC. A literature search for "random start" protocols for controlled ovarian stimulation (COS) for fertility preservation in cancer patients was performed.

Results: The time from OTC-referral to OTC was significantly influenced by diagnosis, age, and referring center. Women with malignant diseases other than breast cancer, such as sarcomas, pelvic cancers, and hematological cancers, experienced a significantly shorter interval to OTC (5 days) than women with breast cancer (7 days) and nonmalignant diseases including systemic, ovarian, and hereditary conditions (13-17.5 days). Women over the age of 30 years experienced a significantly longer time to OTC (P < 0.03), and the diagnosis determined the length of the interval (P < 0.001). According to the literature, fertility preservation by oocyte vitrification requires 13-14 days, as the average time for 1 round of COS was 11 days and oocyte collection can be performed 2 days later.

Conclusions: It is in the interest of both cancer patients and clinicians to perform fertility preservation as quickly and safely as possible. In a Danish setting, OTC provides a short interval of around 6 days from the patient choosing this option to completion of the procedure. This is considerably less time than what is needed to perform COS and oocyte vitrification, and therefore OTC might be considered the preferred choice of fertility preservation when urgency is needed.

Keywords: cancer; fertility preservation; oocyte vitrification; ovarian tissue cryopreservation; random start ovarian stimulation.