Health Sciences-Methodology, University of Manchester, Manchester Academic Health Science Centre, Manchester M13 9WL, UK.
Hum Reprod. 2011 Mar;26(3):569-75. doi: 10.1093/humrep/deq352. Epub 2010 Dec 16.
IVF treatments carry a high risk of twin pregnancy which confers a higher risk to the mother and child than singletons. Increased use of elective single embryo transfer (eSET) can reduce this twin rate. We aimed to utilize a previously published data set and statistical model based on routinely collected clinical data to predict the outcomes of policies that increase the proportion of eSET.
The models allow simultaneous prediction of outcomes from double embryo transfer (DET) and SET. These models were used to predict outcomes for different scenarios using SET in both the initial (fresh) transfer and over a complete cycle (transfer of all embryos created, with cryopreservation). A total of 16 096 cycles (12 487 fresh and 3609 frozen) from 9040 couples treated between 2000 and 2005 were included in the final analyses.
For any transfer, SET has about a one-third lower live birth rate relative to DET: this can be partially mitigated by appropriate patient and treatment cycle selection, with several realistic policies performing similarly. However, if we consider complete cycles with embryo cryopreservation, it is possible for repeat SET to produce more live births per egg retrieval than repeat DET.
All patients receiving SET would have a higher chance of successful treatment in that cycle if they received DET. The selection of appropriate patients for SET can partially ameliorate the overall loss. For complete cycles, repeat SET could produce more live births per egg retrieval than repeat DET. All treatments involving SET will increase the number of treatments required to achieve a successful outcome and this extra treatment burden will be a significant barrier to the implementation of such treatments.
体外受精 (IVF) 治疗具有很高的双胞胎妊娠风险，这比单胎妊娠对母亲和孩子的风险更高。增加选择性单胚胎移植 (eSET) 的使用可以降低这种双胞胎率。我们旨在利用先前发表的数据和基于常规收集的临床数据的统计模型来预测增加 eSET 比例的政策的结果。
这些模型允许同时预测双胚胎移植 (DET) 和 SET 的结果。这些模型用于使用 SET 预测不同场景的结果，包括初始（新鲜）转移和整个周期（转移所有创建的胚胎，包括冷冻保存）。共纳入 9040 对夫妇在 2000 年至 2005 年期间接受的 16096 个周期（12487 个新鲜周期和 3609 个冷冻周期）进行最终分析。
对于任何转移，SET 的活产率相对 DET 降低约三分之一：通过适当的患者和治疗周期选择，可以部分缓解这种情况，几种现实政策的效果相似。然而，如果我们考虑具有胚胎冷冻保存的完整周期，重复 SET 有可能比重复 DET 每取卵获得更多的活产。
如果接受 SET 的所有患者接受 DET，他们在该周期成功治疗的机会将更高。为 SET 选择合适的患者可以部分减轻整体损失。对于完整的周期，重复 SET 每取卵获得的活产可能比重复 DET 多。所有涉及 SET 的治疗都会增加获得成功结果所需的治疗次数，并且这种额外的治疗负担将成为实施这些治疗的重大障碍。
