Technical laboratory procedures faced on many oocytes picked up in vitro fertilization cycles

The accumulation of cryopreserved embryos in assisted reproductive technology (ART) centers is an important point of discussion for the clinical and scientific community. This study conducted a survey to explore in vitro laboratories' approaches to handling oocytes and embryos in the face of an ovarian hyperresponse.

We invited ART centers whose laboratories were registered in the National Embryo Production System (2018) to answer an online multiple-choice questionnaire. A total of 57 ART centers participated.

Most of the ART centers were private (92.9%) and about half of them were considered medium/large business, performing at least 30 IVF cycles per month. The ART centers were asked what their concept of ovarian hyper-responsiveness was, and 76% considered more than 15-20 oocytes retrieved. Faced with an ovarian hyper-responsiveness, the main practice reported was injecting all mature oocytes and vitrifying all developed blastocysts (53%), followed by a practice of freezing half of the oocytes and injecting other half of the oocytes (35%). 9% alternated between these two protocols.

Injection of all oocytes followed by embryos cryopreservation is the most common approach when high order number of oocytes is collected, despite it generating many surplus embryos. The findings of this study underscore the necessity for updated consensus on the management and production of embryos, considering the multifaceted considerations involved, as laboratory efficiency and costs. The decision in such cases should focus on the balance of priorities of having a healthy newborn and the responsibility for the fate of surplus embryos.