Elective single-embryo transfer improves cumulative pregnancy outcome in young patients but not in women of advanced reproductive age.

Abstract

The purpose of the present study is to assess the significance of elective single-embryo transfer (eSET) in older women. The outcomes of assisted reproductive technology between 2001 and 2013 at single institution were retrospectively evaluated. Cumulative live birth rates (CLBRs) in one oocyte retrieval cycle were compared between those who underwent eSET and multiple embryo transfer (MET) in fresh cycles. The outcomes of 429 eSET cycles and 965 MET cycles were compared. CLBRs in eSET were higher than those of MET in women under 37 and were comparable in women aged 37 and over. The analysis of the outcomes separately in three age subgroups showed a significantly higher CLBR in young eSET (aged under 37) than that in young MET and similar CLBR between older (aged 37-40 and over 40) eSET and MET. Multiple birth rates were lower in eSET in all age groups. Multivariate logistic regression analyses showed that, in women aged under 37, number of frozen embryos, presence of good-quality embryos, and eSET were significantly related to cumulative live birth. In women aged between 37 and 40, age and number of frozen embryos were significantly related, while eSET was not. eSET in women under 37 resulted in increased CLBR compared with MET. In women aged between 37 and 40, CLBR in eSET group was similar with that in MET group. In both age groups, eSET reduced multiple birth rates. The significance of eSET in older women is limited presently, and further research on the strategy to improve cumulative outcomes is necessary.