title: Preimplantation genetic screening and human implantation.
abstract: In recent years, preimplantation genetic screening (PGS) has been used and recommended to increase the implantation rate in older women or in couples with previous assisted reproduction (ART) failures, to try to increase pregnancy rates in couples with recurrent abortions, to prevent the transmission of chromosome anomalies to the offspring of carriers of balanced chromosomal rearrangements, or even to try to decrease the incidence of trisomic births in older women. So far, PGS has contributed to increase the implantation rate in older women; however, the rate of clinical pregnancies has not increased, either in older women or in couples with previous ART failures. In couples with recurrent abortions, the pregnancy rate seems to increase, but only when the woman is young (< or =35). In carriers of balanced reorganizations, the prognosis is poor. Attempts to decrease the birth of trisomic children to older women are difficult to evaluate. This absence of relevant results is not related to the technique itself, which is quite safe, but to other still largely unknown factors.
authors.affiliation: Department of Cell Biology, Universitat Autònoma de Barcelona, Edifici CS, 08193 Bellaterra, Spain. josep.egozcue@uab.es
authors.forename: Josep
authors.initials: J
authors.lastname: Egozcue
authors.forename: J
authors.initials: J
authors.lastname: Santaló
authors.forename: C
authors.initials: C
authors.lastname: Giménez
authors.forename: M
authors.initials: M
authors.lastname: Durban
authors.forename: J
authors.initials: J
authors.lastname: Benet
authors.forename: J
authors.initials: J
authors.lastname: Navarro
authors.forename: F
authors.initials: F
authors.lastname: Vidal
mesh_terms: D000026:Abortion, Habitual / Q000235:genetics; D000328:Adult; D002869:Chromosome Aberrations; D010064:Embryo Implantation / Q000235:genetics*; D005260:Female; D005820:Genetic Testing; D006801:Humans; D008423:Maternal Age; D011247:Pregnancy; D019836:Preimplantation Diagnosis; D027724:Reproductive Techniques, Assisted; D014178:Translocation, Genetic