Epigenetics and assisted reproduction.
OBJECTIVE
Epigenetics encompasses multiple mechanisms by which DNA transcription is altered in various tissues and at different times without changing the underlying gene sequence. Epigenetics plays a key role, especially during embryo and trophoblast development. As assisted reproduction technologies (ARTs) are used during these periods, a potential window of vulnerability exists during which epigenetic alterations may occur.


RESULTS
Evidence for epigenetic alterations following ARTs was established based on an increased incidence of imprinting disorders, a particular epimutation in gametes. Recent work suggests induced ovulation and oocytes with potentially less stable imprints may contribute to a higher rate of the maternal imprint disorders noted. Alternatively, new findings of imprinting abnormalities in oligospermatic men again raise the question as to whether subfertility itself is associated with epimutations.


CONCLUSIONS
Currently, our understanding of epigenetics and assisted reproduction is incomplete. Further searches for ART infants with imprinting diseases are hampered by their rare nature. Perhaps more importantly attention has turned to understanding imprinting and epigenetics in placental function. Further analysis of placental epimutations may provide insight into the higher rates of adverse outcomes such as growth restriction that follow ARTs.
Wilkins-Haug
Louise
L
Division of Maternal Fetal Medicine and Reproductive Genetics, Department of Obstetrics and Gynecology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA. lwilkinshaug@partners.org
D025063:Chromosome Disorders / Q000209:etiology*; D005260:Female; D005718:Gametogenesis; D018392:Genomic Imprinting; D006801:Humans; D008297:Male; D009154:Mutation; D010922:Placenta Diseases / Q000235:genetics; D011247:Pregnancy; D027724:Reproductive Techniques, Assisted / Q000009:adverse effects*