Deliveries of babies with normal health derived from oocytes with smooth endoplasmic reticulum clusters

PURPOSE: To examine the impact on development of derived embryos from smooth endoplasmic reticulum clusters (SERC) in human metaphase II (MII) oocytes. METHODS: Retrospective analysis at Kyono ART Clinic. Comparison of embryological development, pregnancy, live birth and fetal malformation between oocytes with SERC (the SERC(+) group) and those without (the SERC(-) group) in 2,158 patients (3,758 cycles) after ICSI. RESULTS: Fertilization and implantation rate were significantly lower in SERC(+) MII oocytes than in SERC(-) MII oocytes. After the transfer of fresh and vitrified embryos derived from SERC(+) oocytes, 14 pregnancies resulted in 14 healthy babies, including 2 from fresh embryo transfer (ET) and 12 from vitrified-warmed ET, with no malformations. CONCLUSION(S): The presence of SERC in MII oocytes was associated with significantly lower fertilization rates and implantation rates than seen in SERC(-) MII oocytes within SERC (+) cycles. However, SERC had no impact on post-implantation development as well as neonatal outcome.