Can cumulative pregnancy rates be increased by freezing and thawing single embryos?

详细信息    查看全文

• 作者：Marie Prades ; Jean-Louis Golmard ; Daniè ; le Vauthier ; Gilles Lefè ; bvre ; Catherine Poirot
• 关键词：Cryopreservation ; single frozen embryo ; implantation ; cumulative pregnancy rate ; embryo survival
• 刊名：Fertility and Sterility
• 出版年：2009
• 出版时间：February 2009
• 年：2009
• 卷：91
• 期：2
• 页码：395-400
• 全文大小：127 K

文摘

Objective

To evaluate the extent to which transfers of frozen single embryos increase cumulative pregnancy rates.

Design

Retrospective analysis.

Setting

IVF unit of a university hospital.

Patient(s)

Patients undergoing IVF cycles that were carried out from 2001 to 2005 (n = 1758). Patients were assigned to three groups according to the number of embryos frozen: group A, no cryopreservation; group B, a single embryo frozen; group C, several embryos frozen.

Intervention(s)

Analysis of fresh ETs as a function of the number of embryos frozen and comparison outcomes for the thawing of a single embryo between subgroups B^* (only one embryo frozen and thawed) and C^* (last embryo of the cohort thawed).

Main Outcome Measure(s)

Implantation and pregnancy rates after fresh ETs and embryo survival and pregnancy rates after the transfer of a single thawed embryo.

Result(s)

The pregnancy rate per fresh ET increased significantly with the number of embryos frozen: 16.2 % in group A, 21.4 % in group B, and 26.5 % in group C. For single thawed embryos, survival was higher in group C^* (91.7 % ) than in group B^* (72.6 % ). The pregnancy rate was also significantly higher in group C^* (19.4 % vs. 0 % ).

Conclusion(s)

The freezing of single embryos is of no benefit in cumulative pregnancy rates. ET strategies should therefore be reviewed.