25. EFFECT ON GROUP CULTURE VS INDIVIDUAL CULTURE ON VIABILITY AND EMBRYO PLOIDY IN PGT-A TREATMENTS

Introduction The main objective is to test if group-culture (GC) improves the embryo viability and ploidy respect to individual-culture (IC). These improvements would base on the existence of paracrine and autocrine factors secreted in the culture medium by embryos (Dai, 2012). In addition to other considerations, for example, the easiness of handling samples. These macromolecules are secreted by the embryos themselves and it will be for their own benefit and for group in the culture, both for the improvement of embryo viability (Tao, 2013) and chromosomal status. Material and methods Our team designed a retrospective study. Using standardized protocols, we studied clinical history, BMI and patient's age. The population studied are embryos obtained by ICSI in patients destined to PGT-A by maternal age indication. Study groups were categorized in embryos GC (38) and IC (182). Mean age (SD) GC 39.41 (3.00) and IC 40.26 (2.58), and BMI mean in GC 23.32 (4.17) and in IC was 24.59 (4.61). These patients were recruited from IVI Las Palmas from April 2016 and September 2017 and patients from IVI Valencia in the period between January and February of 2017. All the embryos were biopsied on day 5 and 6 and subsequently vitrified. Chromosomally normal embryos were transferred in subsequent cycles. Results W Wilcoxom test was applied by variances differences in GC and IC groups and there was no significant differences in maternal age, BMI, and oocytes fertlizated mean. Secondary outcomes were tested where the GC improves in biopsy, pregnancy, implantation, miscarriage and lifebirth rates. The results suggest that there were no significant statistically differences between the GC and IC groups in any rates studied, although it is appreciated that pregnancy rate and implantation rate could evidence statically by the trend to favour GC. To demonstrate a 5% difference in favor of the GC we would need a sample of 900 cases aproximely. Conclusions GC does not improve the results about variables studied against IC, although several studies related it to an improvement in embryo viability. Nevertheless, more extensive and prospective studies are necessary to determine if the GC really improves chromosomal status and variables related to pregnancy in assisted reproduction techniques.