Preimplantation stress and development.

The developmental origins of health and disease hypothesis holds that inappropriate environmental cues in utero, a period marked by tremendous developmental sensitivity, facilitate cellular reprogramming to ultimately predispose disease in adulthood. In this review, we analyze if stress during early stages of development can affect future health. This has wide clinical importance, given that 5 million children have been conceived with assisted reproductive technologies (ART). Because the primary outcome of assisted reproduction procedures is delivery at term of a live, healthy baby, the postnatal effects occurring outside ofthe neonatal period are often overlooked. To this end, the long-term outcome of ART is appropriately the most relevant concern of the field today. Evidence of adverse consequences is controversial. The majority of studies have concluded no obvious problems in IVF-conceived children, although a number of isolated cases of imprinted diseases, cancers, or malformations have been reported. Given that animal studies suggest alteration of metabolic pathways following preimplantation stress, it will be of great importance to follow-up ART individuals as they enter later stages of adult life.