Multiple births following in vitro fertilization treatment: redefining success.

The focus of this article is to review the definition of success following in vitro fertilization (IVF) treatment. Pregnancy rates after IVF have been increasing, but the problem of multiple births with its associated morbidity and mortality has been considerable. This has led to rethinking of assisted reproductive technology (ART) success not only in terms of live birth rates, but also in terms of reduction of multiple births to singleton babies. Single embryo transfer using blastocysts and such other measures are being encouraged. Financial factors and patient satisfaction are key issues. IVF success is thus being redefined.