Prognosis of oocytes showing aggregation of smooth endoplasmic reticulum

Few cytoplasmic dysmorphisms of oocytes have been reported to negatively influence the further fate of the ova. One such anomaly, namely the central aggregation of the smooth endoplasmic reticulum (SER), has recently been associated with suboptimal outcome in a limited number of patients. In order to increase prognostic value, it was decided to prospectively screen all intracytoplasmic sperm injection patients within 1 year for eggs showing aggregations of SER. In addition, all deliveries (obstetric and neonatal data) were analysed. Occurrence of SER cluster was related to duration (P < 0.001) and dosage (P < 0.01) of the stimulation. Fertilization (58.9%) and blastulation rate (44.0%) were lower (P < 0.01) in affected ova compared with unaffected counterparts (77.4 and 87.8%, respectively). Pregnancies in women with affected gametes were accompanied by a higher incidence of obstetric problems (P < 0.01) leading to a non-significant trend towards earlier delivery and significantly reduced birthweight (P < 0.05). It is strongly recommended to avoid transfer of embryos/blastocysts derived from SER cluster-positive gametes. Patients have to be informed that even transfer of sibling oocytes without this anomaly involves a higher risk of detrimental outcome.