The document discusses several new developments in reproductive medicine, including:
1) The use of GnRH antagonists for ovarian stimulation which provides benefits over long GnRH agonist protocols such as less side effects and no difference in live birth rates.
2) Elective single embryo transfer (eSET) which aims to avoid multiple pregnancies and improve pregnancy rates and live birth rates compared to double embryo transfer.
3) Blastocyst culture and vitrification techniques for cryopreservation which provide improved survival and pregnancy rates compared to slow freezing methods.
4) Preimplantation genetic screening (PGS) which aims to select euploid embryos but has not clearly proven benefits to implantation or abortion rates.