Births after a prolonged delay between oocyte recovery and fertilization in vitro

Abstract

Abstract Two normal, healthy children have been born after an oocyte was collected from each of two patients during their natural menstrual cycle, incubated for many hours and then fertilized in vitro. Details of the follicular phase prior to oocyte recovery, fertilization and embryonic development in vitro, and replacement of the embryos are described in detail. One embryo cleaved rapidly after its delayed fertilization, with blastomeres of uneven size and cellular fragments. The luteal phase seemed to be weak in both patients.