同时移植3枚胚胎后发生三胎妊娠的风险因素分析

Analysis of risk factors for triplet pregnancy after a simultaneous transfer of triplicate embryos

目的探讨1次移植3枚胚胎时造成三胎妊娠的风险因素。方法 回顾分析769例一次性移植3枚胚胎周期资料，其中新鲜胚胎移植周期298例、冻融胚胎移植周期471例，分析不同周期类型、女方年龄和移植优胚数与临床妊娠率及二胎妊娠率的关系。结果（1）冻融胚胎移植周期的临床妊娠率56．1％及三胎妊娠率10．2％均显著高于新鲜胚胎移植周期的临床妊娠率48．0％和三胎妊娠率4．2％（均P〈0．05）；（2）新鲜胚胎移植周期中三胎妊娠均发生于年龄〈35岁组（P〈0．01）；冻融胚胎移植周期年龄〈35岁和≥35岁组三胎妊娠率差异无统计学意义（P〉0．05）；（3）新鲜胚胎移植周期移植优胚数分别为0、1、2、3枚时临床妊娠率分别为28．3％、46．7％、50．6％、58．7％，二三胎妊娠率分别为0、2．3％、4．7％、6．8％，移植1枚优胚组与移植2枚优胚组临床妊娠率差异无统计学意义，但有较低的三胎妊娠率（P〈0．05）；冻融胚胎移植周期移植优胚数分别为0、1、2、3枚时临床妊娠率分别为38．9％、54．8％、59．7％、63．9％，三胎妊娠率分别为0、5．0％、13．8％、15．8％，移植l枚优胚组与移植2枚优胚组相比临床妊娠率相近但三胎妊娠率显著降低（P〈0．05）。二胎妊娠均发牛于移植≥1枚优质胚胎周期（P〈0．05）。结论冻融胚胎移植周期较新鲜胚胎移植周期易发生二三胎妊娠；冻融胚胎移植周期可不考虑年龄因素，建议移植≤2枚胚胎，当有≥2枚优质胚胎移植时，建议行选择性单囊胚移植；新鲜胚胎移植周期当有优胚移植且年龄〈35岁时建议移植≤2枚胚胎。

Objective To analyze the risk factors for triplet pregnancy after a simultaneous transfer of triplicate embryos. Methods The investigators carried out a retrospective analysis of 769 cycles in which three embryos were transferred in one treatment cycle, including 298 fresh embryo transfer （ET） cycles and 471 frozen-thawed ET （FET） cycles. The impact of patient age and the number of good embryos transferred on the rates of clinical pregnancy and triplet pregnancy was studied according to different cycle types. Results （ 1 ） The rates of clinical and triplet pregnancy were significantly higher in the FET group （ P 〈 0. 05 ） than those in the fresh ET group; （2） all patients with a triplet pregnancy in the fresh ET group （n =6） were younger than 35 years old （P 〈 0. 01 ）. There was no significant difference between the subgroups in the FET eyele according to patient age （ P 〉 0. 05） ; （3） when none, 1, 2 or 3 good embryos were transferred in the fresh ET cycle, the clinical pregnancy rates were 28.3% , 46.7% , 50. 6% and 58.7% and the triplet pregnancy rates 0, 2. 3% , 4. 7% and 6. 8% respectively. A similar clinical pregnancy rate （P 〉 0. 05） and a significantly lower triplet pregnancy rate （ P 〈 0. 05 ） were observed when 1 good embryo was transferred versus 2 good embryos （ P 〈 0. 05）. When 0, 1,2 or 3 good embryos were transferred in the FET cycle, the clinical pregnancy rates were 38.9% , 54. 8% , 59. 7% , 63.9% and the triplet pregnancy rates 0, 5.0% , 13.8% , 15.8% respectively. A similar clinical pregnancy rate （P 〉0.05） and a significantly lower triplet pregnancy rate （P 〈 0. 05 ） were observed when 1 good embryo was transferred versus two good embryos （ P 〈 0. 05）. All triplet pregnancies occurred in cycles in which more than 1 good embryo was transferred（ P 〈 0.05 ）. Conclusion The patients have more triplet pregnancies in the FET cycle than in the fresh ET cycle. In the FET cycle, the patient age is irrelevant. It is recommended that no more than 2 embryos should be transferred. Selective single blastocyst embryo transfer is preferable if there are more than 2 good embryos available for transfer. No more than 2 embryos should be transferred in the fresh ET cycle if good embryos are available and a patient is under 35 years old.