The impact of Alpha/ESHRE consensus regarding oocytes with aggregates of smooth endoplasmic reticulum (SERa) on in vitro fertilization outcome

The present study aimed to gather information on the impact of Alpha/European Society of Human Reproduction and Embryology (ESHRE) consensus regarding oocytes with aggregates of smooth endoplasmic reticulum (SERa) on in vitro fertilization outcome. In particular, we investigated if patients undergoing intracytoplasmic sperm injection (ICSI) and whose oocytes are discarded due to SERa have a higher chance of embryo transfer cancellation compared to patients without SERa oocytes. This is a nested case-control study drawn from the cohort of women referring for in vitro fertilization with ICSI. Cases were patients showing at least one oocyte with SERa at the time of injection. Controls were subsequent patients showing no SERa oocytes and matched ratio 1:1 for age, clinical indication to in vitro fertilization (IVF), and body mass index. The main outcome was the rate of embryo transfer cancellation. The percentage of women experiencing a transfer cancellation (absence of suitable oocytes or viable embryos) in their ICSI cycle were significantly higher in cases (18 %) compared to controls (8 %) (p = 0.02); however, adjusted odds ratio for FSH and number of SERa oocytes, of follicles, of retrieved oocytes, and of inseminated oocytes were not statistically significant. We have shown that the exclusion of SERa oocytes from ICSI cycles causes an increased frequency of transfer cancellation. This effect is mostly due to the reduced number of available oocytes after exclusion of SERa oocytes.