Can healthy babies originate from oocytes with smooth endoplasmic reticulum aggregates? A systematic mini-review

Abstract

Study question: Is it time to reconsider whether oocytes affected by smooth endoplasmic reticulum aggregates (SERa) should still be destroyed?

Summary answer: At the time of writing, the literature shows that 171 apparently healthy babies have been born from SERa+ cycles amongst which 22 were from SERa+ oocytes.

What is known already: The SER dysmorphism has been associated with negative embryological, clinical and neonatal outcomes, which led to a recommendation in 2011 to avoid inseminating affected oocytes. The data in the literature are nevertheless conflicting and some centres have continued using SERa+ oocytes.

Study design, size, duration: A systematic mini-review of the literature to 7 November 2013 was performed with the keywords 'Smooth Endoplasmic Reticulum' and 'oocyte', limited to humans and written in English.

Participants/materials, setting, methods: Articles (Pubmed) and major abstracts where the effect of the SER dysmorphism was studied as an individual feature on embryological, clinical or neonatal outcomes were included in this review.

Main results and the role of chance: From a total of 297 publications identified, 13 were selected as being relevant to this review. One hundred eighty-three babies have been reported to be born from SERa+ cycles, 171 were healthy, 8 live births presented malformations, 3 were neonatal deaths, 1 was a stillborn and additionally 4 terminations of pregnancy occurred.

Limitations, reasons for caution: Data concerning SERa+ oocytes in the literature are scarce, the studies are small, heterogeneous and results are conflicting. The malformations observed could be due to over-reporting of scattered alarming results. Alternatively, an under-reporting of complications cannot be excluded.

Wider implications of the findings: Centres that have or that are including transfers of SERa+ embryos in their IVF procedures should publish their clinical and neonatal outcomes as well as the follow-up of children. The birth of healthy babies from SERa+ embryos is encouraging and might lead in the future to a revision of the current consensus on the SER dysmorphism. Further research is needed to understand the origin of this dysmorphism and help avoid its occurrence. Therefore, until we have a better understanding of the situation, transfers of affected embryos should be carried out with caution.

Study funding/competing interest(s): We have no conflicts of interest to declare and no funding was received.