Manual of Embryo Culture in Human Assisted Reproduction

"In a span of just a couple of decades, human reproduction has been revolutionized by the widespread use of assisted reproduction. Many couples and individuals who previously could not achieve pregnancy and live birth are now able to fulfill their wish of a family. In addition, it is possible to postpone and plan the time for reproduction through improved cryopreservation techniques for gametes and embryos. Today, assisted reproduction techniques are established all over the world, having led to more than 8 million children born, with an estimated 10 million embryos cryopreserved. It is important to remember that the success of these - now more or less standard - procedures, have been accomplished by the dedicated work of a large number of scientists, embryologists and clinicians. However, despite considerable experimental and clinical research, we still only have a partial understanding of what constitutes a "true" embryo environment. In vivo the oocyte travels from the ovary to the uterus through a landscape of changing physiological conditions. Much effort has been made to mimic this varying environment in the in vitro culture but we still do not know whether in the end the embryos should be in utero for a better environment or maintained in vitro for a better selection. Special focus of research has been directed towards composition of the culture media, handling of the gametes and embryos, and to the design of specialized incubators to create stable and controlled conditions regarding pH, temperature and osmolarity"--