Programmatic implementation of blastocyst transfer in a university-based in vitro fertilization clinic: maximizing pregnancy rates and minimizing triplet rates.

To assess whether the use of extended embryo culture can reduce the incidence of high-order multiple gestations, a retrospective analysis of 7,418 fresh ETs performed in a university-based IVF clinic from 1997-2003 was conducted, comparing program results before and after institution of a protocol to select patients for extended culture of in vitro fertilized embryos. The incidence of triplet pregnancies was significantly reduced in patients at highest risk for high-order multiple gestations, i.e., those at <35 years of age (16.8% versus 6.8%), those at 35-37 years of age (13.0% versus 5.6%), and recipients of donated oocytes (11.2% versus 4.5%).