Dados do Trabalho

Title

In vitro fertilization laboratory practice for handling a large number of oocytes in Brazilian reproductive medicine clinics. Which is the most common practice and its consequences?

Objective

The increase demand for assisted reproduction techniques (ART) leads to a constant improvement in the technologies with the aim of achieving higher pregnancy success rates. The controlled ovarian stimulation (COS) sometimes results in many collected oocytes, which in turn results in a significant number of cryopreserved oocytes and/or embryos. The management of cryopreserved specimens is still uncertain, especially for embryos, and involves ethical, religious, legal, moral, financial, and personal issues. This scenario has generated a significant number of embryos cryopreserved in the ART clinics, which brings discussion leading to a series of discussions about behaviors to reduce surplus embryos. The aim of this study was to assess the profile of in vitro fertilization (IVF) laboratories regarding the handling of oocytes and surplus embryos from women undergoing IVF cycles in Brazil.

Methods

This study was a field research through the application of a multiple-choice questionnaire using an online survey platform (SURVIO). All ART centers, whose laboratories were registered in the National Embryo Production System (SISEMBRIO, 2018) were invited to participate. The questionnaire was developed by the research group and validated before the start of the study. The questions addressed (i) productivity and activity time of the laboratory, (ii) the technical-operational procedures, and (iii) the use and cryopreservation time of the material. The final version, composed of 72 multiple-choice questions pertinent to the understanding of laboratory conduct was sent to 94 IVF laboratories between November 2020 and May 2021. A total of 57 ART centers agreed to participate in the study, and after signature of a consenting term, answered the questionnaire. This study evaluated part of the questionnaire, focusing on technical-operational procedures of IVF laboratories, in the face of ovarian hyper-responsiveness.

Results

Most of the participating ART centers were private (92.9%) and about half of them (47.4%) were considered medium or large, performing at least 30 IVF cycles per month. ART clinics were asked what their concept of ovarian hyper-responsiveness was, and 76% answered that more than 15-20 oocyte collected after a COS. They then answered what was the main conduct when faced with ovarian hyper-responsiveness; 53% reported injecting all mature oocytes and vitrifying all developed blastocysts, 35% reported a fragmental practice of freezing half of the oocytes and the developed blastocysts after injecting half of the oocytes, and 9% alternate between those two protocols. We performed a review of the average cost of IVF laboratory procedures for 15 oocytes. The most common practice of injecting all mature oocytes and vitrifying all developed blastocysts has an average cost of R$4700.00. The approach of fragmental practice has an average cost approximately 40% higher (R$6700.00), while it supposedly could reduce the number of cryopreserved blastocysts.

Conclusion

This study showed that the most commonly used approach in managing a large number of collected oocytes is injection of all oocytes followed by cryopreservation of the developed blastocysts. Despite of that practice has a lower cost, probably results in a higher number of embryos cryopreserved. Moreover, costs may not be the only reason for this choice, but the uncertainty of the yield of oocyte vitrification may contribute to this decision. Given the relevance of this topic and the data presented, it is evident the need to update the consensus belongs conducts regarding the production and management of oocytes and embryos, considering the responsibly and benevolently the parties involved. Guidelines in reproductive medicine practices are essential. Moderating ovarian stimulation and encouraging oocyte cryopreservation are option to avoid high embryo production, besides of outlining issues such as embryo discard and abandonment.

Keywords

embryo cryopreservation; oocyte cryopreservation; surplus embryos, ovarian stimulation; IVF laboratory conduct