The course of pregnancy and subsequent health of the woman and of her offspring are highly influenced by events in the period between preconception and establishment of ongoing pregnancy. Periconceptional events during gametogenesis, fertilization, implantation and placentation not only determine fertility, but the risk of developing severe conditions of pregnancy such as pre-eclampsia, growth retardation and gestational diabetes, and the long-term health of the offspring. The intrauterine environment has been shown to be a factor in programming fetal development and adaptation, directly impacting on postnatal and later adult health.
While the importance of this crucial and sensitive period for fertility and health is now clear, research in this area has primarily focused on factors determining embryo development in vivo and in vitro, leading in turn to more effective fertility treatments. However, in recent years in vitro fertilization (IVF) pregnancy rates have plateaued. It is now recognized that achieving further improvements in the efficacy and long-term safety of IVF will require a greater understanding of the role of the endometrium in implantation, and the establishment of a healthy placenta, pregnancy and child. Current demographic and societal changes render this area of endeavour particularly important at this time. Aging of the population, rising levels of obesity and changing patterns of reproductive behavior, including increasing delay in childbearing, threaten to have profound effects on the health and demographic balance of Western societies. To meet this challenge, significant improvements in the effectiveness of fertility treatments, the prevention and treatment of pregnancy complications and the promotion of periconceptional health are required.