Experience with the elective transfer of two embryos under the conditions of the german embryo protection law: results of a retrospective data analysis of 2573 transfer cycles.

The German embryo protection law (Embryonenschutzgesetz, ESchG) does not allow embryo selection. Therefore, only as many oocytes at the pronuclear stage (PN), as are planned to be transferred, are allowed to be cultured. It is not known whether, under these conditions, it is possible to reduce the number of embryos for transfer without a corresponding reduction of the overall pregnancy rate (PR). We retrospectively analysed 2573 consecutive transfer cycles following either in-vitro fertilization (IVF) or IVF/intracytoplasmic sperm injection. Out of these cycles, 234, 329 and 792 were performed with one, two, and three embryos respectively, because only that number was available (non-elective transfer). Another 123 and 1095 transfer cycles were performed with two and three embryos, respectively, which were selected from a higher number of PN oocytes (elective transfer). The clinical ongoing PR were 3.9, 9.1 and 17.7% respectively for the groups with non-elective transfer of 1, 2 and 3 embryos, and 22.0 and 22.5% for the groups with elective transfers with two and three embryos, respectively. There was no statistically significant difference in PR between the two elective embryo transfer groups up to the age of 40 years. The multiple pregnancy rate was reduced by 7.9%. The reduction of the number of embryos transferred from three to two can be performed even under the conditions of the ESchG without an effect on the overall PR.

[1]  A. Antsaklis,et al.  Reduction of multifetal pregnancies to twins does not increase obstetric or perinatal risks. , 1999, Human reproduction.

[2]  S. Emiliani,et al.  Comparison of two elective transfer policies of two embryos to reduce multiple pregnancies without impairing pregnancy rates. , 1999, Human reproduction.

[3]  Y. Saito,et al.  Reducing multiple pregnancies by restricting the number of embryos transferred to two at the first embryo transfer attempt. , 1998, Human reproduction.

[4]  D. Gardner,et al.  A prospective randomized trial of blastocyst culture and transfer in in-vitro fertilization. , 1998, Human reproduction.

[5]  M. Dhont,et al.  Avoiding multiple pregnancies in in-vitro fertilization: who's afraid of single embryo transfer? , 1998, Human reproduction.

[6]  A. Templeton,et al.  Reducing the risk of multiple births by transfer of two embryos after in vitro fertilization. , 1998, The New England journal of medicine.

[7]  M. Evans,et al.  Selective termination and elective reduction in twin pregnancies: 10 years experience at a single centre. , 1998, Human reproduction.

[8]  J. Cohen.  How to avoid multiple pregnancies in assisted reproduction. , 1998, Human reproduction.

[9]  L A Scott,et al.  The successful use of pronuclear embryo transfers the day following oocyte retrieval. , 1998, Human reproduction.

[10]  Assisted reproductive technology in the United States and Canada: 1995 results generated from the American Society for Reproductive Medicine/Society for Assisted Reproductive Technology Registry. , 1998, Fertility and sterility.

[11]  D. Gardner,et al.  Culture and transfer of human blastocysts increases implantation rates and reduces the need for multiple embryo transfers. , 1998, Fertility and sterility.

[12]  G. Zeilmaker,et al.  Blastocyst transfer in day-5 embryo transfer depends primarily on the number of oocytes retrieved and not on age. , 1998, Fertility and sterility.

[13]  K. Faber.  IVF in the US: multiple gestation, economic competition, and the necessity of excess. , 1997, Human reproduction.

[14]  D. Gardner,et al.  Culture and selection of viable blastocysts: a feasible proposition for human IVF? , 1997, Human reproduction update.

[15]  J. Lessing,et al.  The optimal number of embryos to be transferred in shared oocyte donation: walking the thin line between low pregnancy rates and multiple pregnancies. , 1997, Human reproduction.

[16]  S. Muasher,et al.  The incidence of multiple gestations after in vitro fertilization is dependent on the number of embryos transferred and maternal age. , 1996, Fertility and sterility.

[17]  K. Diedrich,et al.  Comparison of cryopreservation of supernumerary pronuclear human oocytes obtained after intracytoplasmic sperm injection (ICSI) and after conventional in-vitro fertilization. , 1996, Human reproduction.

[18]  Z. Nagy,et al.  One year's experience with elective transfer of two good quality embryos in the human in-vitro fertilization and intracytoplasmic sperm injection programmes. , 1995, Human reproduction.

[19]  T. Roseboom,et al.  The probability of pregnancy after embryo transfer is affected by the age of the patient, cause of infertility, number of embryos transferred and the average morphology score, as revealed by multiple logistic regression analysis. , 1995, Human reproduction.

[20]  J. Conaghan,et al.  Delaying transfer to the third day post-insemination, to select non-arrested embryos, increases development to the fetal heart stage. , 1995, Human reproduction.

[21]  P. Devroey,et al.  Avoidance of triplet pregnancies by elective transfer of two good quality embryos. , 1993, Human reproduction.

[22]  C. Johannes.  Correction to “Medical Research International, Society for Assisted Reproductive Technology (SART), The American Fertility Society. In vitro fertilization-embryo transfer (lVF -ET) in the United States: 1990 results from the IVF-ET registry. Fertil Steril 1992;57:15–24.” , 1993 .

[23]  P. Brinsden.  A Textbook of In Vitro Fertilization and Assisted Reproduction : The Bourn Hall Guide to Clinical and Laboratory Practice , 2005 .

[24]  P. Kaiser,et al.  Embryonenschutzgesetz : Kommentar zum Embryonenschutzgesetz , 1992 .

[25]  S. Campbell,et al.  The cumulative embryo score: a predictive embryo scoring technique to select the optimal number of embryos to transfer in an in-vitro fertilization and embryo transfer programme. , 1992, Human reproduction.