title: [First experiences with human blastocyst culture after IVF/ICSI under the conditions of the German embryo protection law].
abstract: OBJECTIVE
  Due to the improvements in human embryo culture in the recent years, it is now possible to transfer embryos five days after oocyte retrieval and IVF or ICSI at the blastocyst stage with favorable implantation rates. In Germany it is illegal to cultivate more than 3 embryos, therefore the selection has to be done at the pronuclear stage. There we report our experiences of human blastocyst culture in a routine IVF/ICSI programme under the conditions of the German Embryo Protection Law.
  
  
  METHODS
  The data of 100 couples undergoing the IVF-ICSI programme at the University Clinic of Würzburg were analysed prospectively. 14-18 hours after insemination or micro-injection two or three zygotes with the best pronuclear development were selected for further cultivation. Fertilized oocytes were cultured in sequential media and were then transferred into the uterus 5 days after oocyte recovery. The blastocysts were graded from 1-8.
  
  
  RESULTS
  In 100 cycles a total of 859 oocytes were collected, of whom 663 were fertilized and reached the pronuclear stage (median fertilization rate 88.9 %). 251 zygotes were selected at the PN stage. 51 % of the selected zygotes achieved the blastocyst stage after 5 days (grade 1-5), 28 % were morulae (grade 6-7) and 21 % of the embryos arrested in their development (grade 8). The clinical pregnancy rate was 26 %. Women who conceived had a significant better development of blastocysts on day 5 (grade 4 versus grade 6, P < 0.01) than those not achieving pregnancy.
  
  
  CONCLUSIONS
  In summary, under the current legal conditions in Germany, blastocyst culture cannot improve pregnancy rates as the rate of arrested embryos of over 20 % limits the chances of implantation.
authors.affiliation: Universitäts-Frauenklinik Würzburg, Germany. kp.zollner@mail.uni-wuerzburg.de
authors.forename: K P
authors.initials: KP
authors.lastname: Zollner
authors.forename: U
authors.initials: U
authors.lastname: Zollner
authors.forename: T
authors.initials: T
authors.lastname: Steck
authors.forename: J
authors.initials: J
authors.lastname: Dietl
mesh_terms: D000328:Adult; D010064:Embryo Implantation; D004624:Embryo Transfer; D004992:Ethics, Medical; D005260:Female; D005307:Fertilization in Vitro; D005858:Germany; D006801:Humans; D007231:Infant, Newborn; D010043:Outcome and Process Assessment, Health Care; D011247:Pregnancy; D020554:Sperm Injections, Intracytoplasmic
vernacular_title: Erste Erfahrungen mit der Blastozystenkultur nach IVF oder ICSI unter den Bedingungen des Deutschen Embryonenschutzgesetzes.